A graphene oxide-based electrochemical sensor for sensitive determination of 4-nitrophenol
作者：
Li, Junhua* ;Kuang, Daizhi;Feng, Yonglan;Zhang, Fuxing;Xu, Zhifeng;...
期刊：
Journal of Hazardous Materials ,2012年201-202:250-259 ISSN：0304-3894
通讯作者：
Li, Junhua
作者机构：
[Liu, Mengqin; Xu, Zhifeng; Li, Junhua; Zhang, Fuxing; Feng, Yonglan; Kuang, Daizhi] Hengyang Normal Univ, Dept Chem & Mat Sci, Hengyang 421008, Hunan, Peoples R China.;[Liu, Mengqin; Xu, Zhifeng; Li, Junhua; Zhang, Fuxing; Feng, Yonglan; Kuang, Daizhi] Hengyang Normal Univ, Hunan Prov College, Key Lab Funct Organometall Mat, Hengyang 421008, Hunan, Peoples R China.
通讯机构：
[Li, Junhua] H;Hengyang Normal Univ, Dept Chem & Mat Sci, Hengyang 421008, Hunan, Peoples R China.
关键词：
Graphene oxide;Electrochemical sensor;4-Nitrophenol;Sensitive detection
摘要：
A graphene oxide (GO) film coated glassy carbon electrode (GCE) was fabricated for sensitive determination of 4-nitrophenol (4-NP). The GO-based sensor was characterized by scanning electron microscope, atomic force microscopy and electrochemical impedance spectroscopy. The electrochemical behaviors of 4-NP at the GO-film coated GCE were investigated in detail. In 0.1 M acetate buffer with a pH of 4.8, 4-NP yields a very sensitive and well-defined reduction peak at the GO-modified GCE. It is found that the GO film exhibits obvious electrocatalytic activity toward the reduction of 4-NP since it not only increases the reduction peak current but also lowers the reduction overpotential. Based on this, an electrochemical method was proposed for the direct determination of 4-NP. Various kinetic parameters such as transfer electron number, transfer proton number and standard heterogeneous rate constant were calculated, and various experimental parameters were also optimized. Under the optimal conditions, the reduction peak current varies linearly with the concentration of 4-NP ranging from 0.1 to 120 mu M, and the detection limit is 0.02 mu M at the signal noise ratio of 3. Moreover, the fabricated sensor presented high selectivity and long-term stability. This electrochemical sensor was further applied to determine 4-NP in real water samples, and it showed great promise for simple, sensitive, and quantitative detection of 4-NP. (C) 2011 Elsevier B.V. All rights reserved.
语种：
英文
展开
Bag of visual words and fusion methods for action recognition: Comprehensive study and good practice
作者：
Peng, Xiaojiang* ;Wang, Limin;Wang, Xingxing;Qiao, Yu
期刊：
Computer Vision and Image Understanding ,2016年150:109-125 ISSN：1077-3142
通讯作者：
Peng, Xiaojiang
作者机构：
[Peng, Xiaojiang] Hengyang Normal Univ, Coll Comp Sci & Technol, Hengyang, Peoples R China.;[Wang, Limin] Swiss Fed Inst Technol, Comp Vis Lab, Zurich, Switzerland.;[Wang, Xingxing; Qiao, Yu; Wang, Limin; Peng, Xiaojiang] Chinese Acad Sci, Shenzhen Inst Adv Technol, Shenzhen, Peoples R China.;[Peng, Xiaojiang] INRIA, LEAR Team, Grenoble, France.
通讯机构：
[Peng, Xiaojiang] H;[Peng, Xiaojiang] C;[Peng, Xiaojiang] I;Hengyang Normal Univ, Coll Comp Sci & Technol, Hengyang, Peoples R China.;Chinese Acad Sci, Shenzhen Inst Adv Technol, Shenzhen, Peoples R China.
关键词：
Action recognition;Bag of visual words;Feature encoding;Fusion methods
摘要：
A Comprehensive study on the BoVW pipeline for action recognition task.An evaluation and a generic analysis on 13 encoding methods.Intra-normalization for supervector based encoding methods.An evaluation on three fusion methods.Several good practices of the BoVW pipeline for action recognition task. Video based action recognition is one of the important and challenging problems in computer vision research. Bag of visual words model (BoVW) with local features has been very popular for a long time and obtained the state-of-the-art performance on several realistic datasets, such as the HMDB51, UCF50, and UCF101. BoVW is a general pipeline to construct a global representation from local features, which is mainly composed of five steps; (i) feature extraction, (ii) feature pre-processing, (iii) codebook generation, (iv) feature encoding, and (v) pooling and normalization. Although many efforts have been made in each step independently in different scenarios, their effects on action recognition are still unknown. Meanwhile, video data exhibits different views of visual patterns , such as static appearance and motion dynamics. Multiple descriptors are usually extracted to represent these different views. Fusing these descriptors is crucial for boosting the final performance of an action recognition system. This paper aims to provide a comprehensive study of all steps in BoVW and different fusion methods, and uncover some good practices to produce a state-of-the-art action recognition system. Specifically, we explore two kinds of local features, ten kinds of encoding methods, eight kinds of pooling and normalization strategies, and three kinds of fusion methods. We conclude that every step is crucial for contributing to the final recognition rate and improper choice in one of the steps may counteract the performance improvement of other steps. Furthermore, based on our comprehensive study, we propose a simple yet effective representation, called hybrid supervector, by exploring the complementarity of different BoVW frameworks with improved dense trajectories. Using this representation, we obtain impressive results on the three challenging datasets; HMDB51 (61.9%), UCF50 (92.3%), and UCF101 (87.9%).
语种：
英文
展开
Visible-Frequency Metasurface for Structuring and Spatially Multiplexing Optical Vortices
作者：
Mehmood, M. Q.;Mei, Shengtao;Hussain, Sajid;Huang, Kun;Siew, S. Y.;...
期刊：
Advanced Materials ,2016年28(13):2533-2539 ISSN：0935-9648
通讯作者：
Qiu, Cheng-Wei
作者机构：
[Mei, Shengtao; Mehmood, M. Q.; Zhang, Tianhang; Ling, Xiaohui; Zhang, Lei; Qiu, Cheng-Wei; Hussain, Sajid; Danner, Aaron; Siew, S. Y.] Natl Univ Singapore, Dept Elect & Comp Engn, 4 Engn Dr 3, Singapore 117583, Singapore.;[Mei, Shengtao; Qiu, Cheng-Wei] Natl Univ Singapore, Ctr Life Sci CeLS, Grad Sch Integrat Sci & Engn, 05-01,28 Med Dr, Singapore 117456, Singapore.;[Liu, Hong; Huang, Kun; Teng, Jinghua] Innovis, A STAR, Inst Mat Res & Engn, 08-03,2 Fusionopolis Way, Singapore 138634, Singapore.;[Ling, Xiaohui] Hengyang Normal Univ, Coll Phys & Elect Engn, Hengyang 421002, Peoples R China.;[Zhang, Shuang] Univ Birmingham, Sch Phys & Astron, Birmingham B15 2TT, W Midlands, England.
通讯机构：
[Qiu, Cheng-Wei] N;Natl Univ Singapore, Dept Elect & Comp Engn, 4 Engn Dr 3, Singapore 117583, Singapore.;Natl Univ Singapore, Ctr Life Sci CeLS, Grad Sch Integrat Sci & Engn, 05-01,28 Med Dr, Singapore 117456, Singapore.
关键词：
babinet-inverted;metalens;multifocus;optical-vortex beam;topological charge
摘要：
A multifocus optical vortex metalens, with enhanced signal-to-noise ratio, is presented, which focuses three longitudinal vortices with distinct topological charges at different focal planes. The design largely extends the flexibility of tuning the number of vortices and their focal positions for circularly polarized light in a compact device, which provides the convenience for the nanomanipulation of optical vortices. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
语种：
英文
展开
Recent advances in the spin Hall effect of light
作者：
Ling, Xiaohui;Zhou, Xinxing;Huang, Kun;Liu, Yachao;Qiu, Cheng-Wei* ;...
期刊：
Reports on Progress in Physics ,2017年80(6):066401 ISSN：0034-4885
通讯作者：
Qiu, Cheng-Wei
作者机构：
[Ling, Xiaohui] Hengyang Normal Univ, Coll Phys & Elect Engn, Hunan Prov Key Lab Intelligent Informat Proc & Ap, Hengyang 421002, Peoples R China.;[Qiu, Cheng-Wei; Ling, Xiaohui] Natl Univ Singapore, Dept Elect & Comp Engn, 4 Engn Dr 3, Singapore 117576, Singapore.;[Wen, Shuangchun; Luo, Hailu; Ling, Xiaohui; Liu, Yachao] Hunan Univ, Sch Phys & Elect, Minist Educ, Lab Micro Nanooptoelect Devices, Changsha 410082, Hunan, Peoples R China.;[Zhou, Xinxing] Hunan Normal Univ, Coll Phys & Informat Sci, Synerget Innovat Ctr Quantum Effects & Applicat, Changsha 410081, Hunan, Peoples R China.;[Huang, Kun] Agcy Sci Technol & Res, Inst Mat Res & Engn, 2 Fusionopolis Way,Innovis 08-03, Singapore 138634, Singapore.
通讯机构：
[Qiu, Cheng-Wei] N;[Qiu, Cheng-Wei] S;Natl Univ Singapore, Dept Elect & Comp Engn, 4 Engn Dr 3, Singapore 117576, Singapore.;Shenzhen Univ, SZU NUS Collaborat Innovat Ctr Optoelect Sci & Te, Shenzhen 518060, Peoples R China.;NUS Suzhou Res Inst NUSRI, Suzhou Ind Pk, Suzhou 215123, Peoples R China.
关键词：
geometric phase;spin Hall effect of light;spin Hall shift;weak measurements
摘要：
The spin Hall effect (SHE) of light, as an analogue of the SHE in electronic systems, is a promising candidate for investigating the SHE in semiconductor spintronics/valleytronics, high-energy physics and condensed matter physics, owing to their similar topological nature in the spin-orbit interaction. The SHE of light exhibits unique potential for exploring the physical properties of nanostructures, such as determining the optical thickness, and the material properties of metallic and magnetic thin films and even atomically thin two-dimensional materials. More importantly, it opens a possible pathway for controlling the spin states of photons and developing next-generation photonic spin Hall devices as a fundamental constituent of the emerging spinoptics. In this review, based on the viewpoint of the geometric phase gradient, we give a detailed presentation of the recent advances in the SHE of light and its applications in precision metrology and future spin-based photonics. © 2017 IOP Publishing Ltd.
语种：
英文
展开
Injection of oxygen vacancies in the bulk lattice of layered cathodes
作者：
Yan, Pengfei* ;Zheng, Jianming;Tang, Zhen-Kun;Devaraj, Arun;Chen, Guoying;...
期刊：
Nature Nanotechnology ,2019年14(6):602-608 ISSN：1748-3387
通讯作者：
Yan, Pengfei;Wang, Chongmin;Liu, Li-Min
作者机构：
[Devaraj, Arun; Yan, Pengfei; Wang, Chongmin] Pacific Northwest Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA.;[Yan, Pengfei] Beijing Univ Technol, Inst Microstruct & Properties Adv Mat, Beijing Key Lab Microstruct & Properties Solids, Beijing, Peoples R China.;[Zheng, Jianming; Zhang, Ji-Guang] Pacific Northwest Natl Lab, Energy & Environm Directorate, Richland, WA 99352 USA.;[Tang, Zhen-Kun] Hengyang Normal Univ, Coll Phys & Elect Engn, Hengyang, Peoples R China.;[Tang, Zhen-Kun; Liu, Li-Min] Beihang Univ, Sch Phys, Beijing, Peoples R China.
通讯机构：
[Yan, PF; Wang, CM] P;[Yan, Pengfei; Liu, Li-Min] B;Pacific Northwest Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA.;Beijing Univ Technol, Inst Microstruct & Properties Adv Mat, Beijing Key Lab Microstruct & Properties Solids, Beijing, Peoples R China.;Beihang Univ, Sch Phys, Beijing, Peoples R China.
摘要：
Surfaces, interfaces and grain boundaries are classically known to be sinks of defects generated within the bulk lattice. Here, we report an inverse case by which the defects generated at the particle surface are continuously pumped into the bulk lattice. We show that, during operation of a rechargeable battery, oxygen vacancies produced at the surfaces of lithium-rich layered cathode particles migrate towards the inside lattice. This process is associated with a high cutoff voltage at which an anionic redox process is activated. First-principle calculations reveal that triggering of this redox process leads to a sharp decrease of both the formation energy of oxygen vacancies and the migration barrier of oxidized oxide ions, therefore enabling the migration of oxygen vacancies into the bulk lattice of the cathode. This work unveils a coupled redox dynamic that needs to be taken into account when designing high-capacity layered cathode materials for high-voltage lithium-ion batteries. © 2019, This is a U.S. government work and not under copyright protection in the U.S.; foreign copyright protection may apply.
语种：
英文
展开
Giant photonic spin Hall effect in momentum space in a structured metamaterial with spatially varying birefringence
作者：
Ling, Xiaohui;Zhou, Xinxing;Yi, Xunong;Shu, Weixing;Liu, Yachao;...
期刊：
光：科学与应用 ,2015年4(5): ISA.2015.63_01-ISA.2015.63_06 ISSN：2095-5545
通讯作者：
Luo, Hailu
作者机构：
[Fan, Dianyuan; Shu, Weixing; Wen, Shuangchun; Luo, Hailu; Zhou, Xinxing; Ling, Xiaohui; Liu, Yachao; Chen, Shizhen] Hunan Univ, Sch Phys & Elect, Lab Spin Photon, Changsha 410082, Hunan, Peoples R China.;[Ling, Xiaohui] Hengyang Normal Univ, Dept Phys & Elect Informat Sci, Hengyang 421002, Peoples R China.;[Fan, Dianyuan; Yi, Xunong; Ling, Xiaohui] Shenzhen Univ, SZU NUS Collaborat Innovat Ctr Optoelect Sci & Te, Shenzhen 518060, Peoples R China.;[Fan, Dianyuan; Yi, Xunong; Ling, Xiaohui] Shenzhen Univ, Key Lab Optoelect Devices & Syst, Minist Educ & Guangdong Prov, Shenzhen 518060, Peoples R China.
通讯机构：
[Luo, Hailu] H;Hunan Univ, Sch Phys & Elect, Lab Spin Photon, Changsha 410082, Hunan, Peoples R China.
关键词：
geometric phase;metamaterial;photonic spin Hall effect
摘要：
The photonic spin Hall effect (SHE) in the reflection and refraction at an interface is very weak because of the weak spin-orbit interaction. Here, we report the observation of a giant photonic SHE in a dielectric-based metamaterial. The metamaterial is structured to create a coordinate-dependent, geometric Pancharatnam Berry phase that results in an SHE with a spin-dependent splitting in momentum space. It is unlike the SHE that occurs in real space in the reflection and refraction at an interface, which results from the momentum-dependent gradient of the geometric Rytov Vladimirskii Berry phase. We theorize a unified description of the photonic SHE based on the two types of geometric phase gradient, and we experimentally measure the giant spin-dependent shift of the beam centroid produced by the metamaterial at a visible wavelength. Our results suggest that the structured metamaterial offers a potential method of manipulating spin-polarized photons and the orbital angular momentum of light and thus enables applications in spin-controlled nanophotonics. © 2015 CIOMP.
语种：
英文
展开
A promising sensing platform toward dopamine using MnO2 nanowires/electro-reduced graphene oxide composites
作者：
He, Quanguo;Liu, Jun;Liu, Xiaopeng;Li, Guangli* ;Chen, Dongchu;...
期刊：
Electrochimica Acta ,2019年296:683-692 ISSN：0013-4686
通讯作者：
Deng, Peihong;Li, Guangli
作者机构：
[He, Quanguo; Li, Guangli; Liang, Jing; Liu, Xiaopeng; Liu, Jun] Hunan Univ Technol, Coll Life Sci & Chem, Hunan Key Lab Biomed Nanomat & Devices, Zhuzhou 412007, Peoples R China.;[Chen, Dongchu] Foshan Univ, Sch Mat Sci & Energy Engn, Foshan 528000, Peoples R China.;[Deng, Peihong] Hengyang Normal Univ, Dept Chem & Mat Sci, 165 Huangbai Rd, Yanfeng Dist 421008, Hengyang, Peoples R China.;[Li, Guangli] Hunan Univ Technol, Coll Life Sci & Chem, 88 West Taishan Rd, Tianyuan Dist 412007, Zhuzhou, Peoples R China.
通讯机构：
[Deng, Peihong; Li, Guangli] H;Hengyang Normal Univ, Dept Chem & Mat Sci, 165 Huangbai Rd, Yanfeng Dist 421008, Hengyang, Peoples R China.;Hunan Univ Technol, Coll Life Sci & Chem, 88 West Taishan Rd, Tianyuan Dist 412007, Zhuzhou, Peoples R China.
关键词：
MnO2 nanowires;Reduced graphene oxide;Modified electrode;Dopamine sensor;Electrocatalytic oxidation
摘要：
A promising sensing platform for the ultrasensitive detection of dopamine (DA) has been constructed using MnO2 nanowires-electrochemically reduced graphene oxide modified glassy carbon electrode (MnO2 NWs-ErGO/GCE). The proposed MnO2 NWs-ErGO/GCEs had the large electrochemical active area and relative low charge transfer resistant (R-ct). As a result, the response peak current of the MnO2 NWs-ErGO is about 13 times higher than that of the bare GCE, demonstrating the remarkable electrocatalytic activity toward DA. The electrochemical kinetics revealed that DA oxidation is quasi-reversible reaction coupling with one electron and two protons. Three linear ranges (0.01 mu M - 0.10 mu M, 0.10 mu M - 1.0 mu M, and 1.0 mu M - 80 mu M) were obtained on the MnO2 NWs-ErGO/GCE, with a low detection limit of 1.0 nM (S/N = 3). Moreover, the response current was almost unaltered even in the presence of 100-fold ascorbic acid (AA) and uric acid (UA), suggesting MnO2 NWs-ErGO has good selectivity toward DA. Finally, the MnO2 NWs-ErGO/GCEs were successfully applied to detect DA in the injection solutions and human blood serum samples with high accuracy and good recovery. (C) 2018 Elsevier Ltd. All rights reserved.
语种：
英文
展开
High-sensitivity paracetamol sensor based on Pd/graphene oxide nanocomposite as an enhanced electrochemical sensing platform
作者：
Li, Junhua;Liu, Jinlong;Tan, Gongrong;Jiang, Jianbo;Peng, Sanjun;...
期刊：
Biosensors and Bioelectronics ,2014年54:468-475 ISSN：0956-5663
通讯作者：
Qian, Dong
作者机构：
[Liu, Youcai; Liu, Jinlong; Tan, Gongrong; Li, Junhua; Peng, Sanjun; Deng, Miao; Jiang, Jianbo; Qian, Dong] Cent S Univ, Coll Chem & Chem Engn, Changsha 410083, Hunan, Peoples R China.;[Li, Junhua; Feng, Yonglan] Hengyang Normal Univ, Dept Chem & Mat Sci, Hengyang 421008, Peoples R China.;[Li, Junhua; Qian, Dong] Cent S Univ, State Key Lab Powder Met, Changsha 410083, Hunan, Peoples R China.
通讯机构：
[Qian, Dong] C;Cent S Univ, Coll Chem & Chem Engn, Changsha 410083, Hunan, Peoples R China.
关键词：
Pd nanoparticles;Graphene oxide;Electrochemical sensor;Paracetamol
摘要：
Well-dispersed Pd nanoparticles were facilely anchored on graphene oxide (Pd/GO) via a one-pot chemical reduction of the Pd2+ precursor without any surfactants and templates. The morphology and composition of the Pd/GO nanocomposite were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR) and energy dispersive analysis of X-ray (EDX). The stepwise fabrication process of the Pd/GO modified electrode and its electrochemical sensing performance towards paracetamol was evaluated using electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The experimental results indicate that the as-synthesized Pd nanoparticles are relatively uniform in size (5-10nm) without large aggregation and uniformly distributed in the carbon matrix with the overall Pd content of 28.77wt% in Pd/GO. Compared with the GO modified electrode, the Pd/GO modified electrode shows a better electrocatalytic activity to the oxidation of paracetamol with lower oxidation potential and larger peak current, so the Pd/GO nanocomposite can be used as an enhanced sensing platform for the electrochemical determination of paracetamol. The kinetic parameters of the paracetamol electro-oxidation at Pd/GO electrode were studied in detail, and the determination conditions were optimized. Under the optimal conditions, the oxidation peak current is linear to the paracetamol concentration in the ranges of 0.005-0.5μM and 0.5-80.0μM with a detection limit of 2.2nM. Based on the high sensitivity and good selectivity of the Pd/GO modified electrode, the proposed method was successfully applied to the determination of paracetamol in commercial tablets and human urines, and the satisfactory results confirm the applicability of this sensor in practical analysis. © 2013 Elsevier B.V.
语种：
英文
展开
Green synthesis of silver nanoparticles-graphene oxide nanocomposite and its application in electrochemical sensing of tryptophan
作者：
Li, Junhua* ;Kuang, Daizhi;Feng, Yonglan;Zhang, Fuxing;Xu, Zhifeng;...
期刊：
Biosensors and Bioelectronics ,2013年42(1):198-206 ISSN：0956-5663
通讯作者：
Li, Junhua
作者机构：
[Liu, Mengqin; Xu, Zhifeng; Li, Junhua; Zhang, Fuxing; Feng, Yonglan; Kuang, Daizhi; Wang, Deping] Hengyang Normal Univ, Dept Chem & Mat Sci, Hengyang 421008, Hunan, Peoples R China.;[Liu, Mengqin; Xu, Zhifeng; Li, Junhua; Zhang, Fuxing; Feng, Yonglan; Kuang, Daizhi; Wang, Deping] Hengyang Normal Univ, Hunan Prov Coll, Key Lab Funct Organometall Mat, Hengyang 421008, Hunan, Peoples R China.;[Li, Junhua] Hengyang Normal Univ, Dept Chem & Mat Sci, 165 Huangbai Rd, Hengyang 421008, Hunan, Peoples R China.
通讯机构：
[Li, Junhua] H;Hengyang Normal Univ, Dept Chem & Mat Sci, 165 Huangbai Rd, Hengyang 421008, Hunan, Peoples R China.
关键词：
Graphene oxide;Silver nanoparticles;Tryptophan sensor;Electrochemical tryptophan detection
摘要：
A new kind of nanocomposite based on silver nanoparticles (AgNPs)/graphene oxide (GO) was conveniently achieved through a green and low-cost synthesis approach using glucose as a reducing and stabilizing agent, and the synthetic procedure can be easily used for the construction of a disposable electrochemical sensor on glassy carbon electrode (GCE). The nanocomposite was detailedly characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX), Fourier transform infrared spectroscopy (FTIR) and electrochemical impedance spectroscopy (EIS). The experimental results demonstrated that the nanocomposite possessed the specific features of both silver nanoparticles and graphene, and the intrinsic high specific area and the fast electron transfer rate ascribed to the nanohybrid structure could improve its electrocatalytic performance greatly. Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were employed to evaluate the electrochemical properties of AgNPs/GO/GCE towards tryptophan, and the AgNPs/GO film exhibited a distinctly higher activity for the electro-oxidation of tryptophan than GO film with tenfold enhancement of peak current. The oxidation mechanism and the kinetic parameters were investigated, and analysis operation conditions were optimized. Under the selected experimental conditions, the oxidation peak currents were proportional to tryptophan concentrations over the range of 0.01. μM to 50.0. μM and 50.0. μM to 800.0. μM, respectively. The detection limit was 2.0. nM (S/. N=3). Moreover, the proposed method is free of interference from tyrosine and other coexisting species. The resulting sensor displays excellent repeatability and long-term stability; finally it was successfully applied to detect tryptophan in real samples with good recoveries, ranging from 99.0% to 103.0%. © 2012 Elsevier B.V.
语种：
英文
展开
Broadband Vortex Beam Generation Using Multimode Pancharatnam-Berry Metasurface
作者：
Xu, He-Xiu* ;Liu, Haiwen;Ling, Xiaohui;Sun, Yunming;Yuan, Fang
期刊：
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION ,2017年65(12):7378-7382 ISSN：0018-926X
通讯作者：
Xu, He-Xiu
作者机构：
[Xu, He-Xiu; Ling, Xiaohui] Hengyang Normal Univ, Coll Phys & Elect Engn, Hengyang 421002, Peoples R China.;[Yuan, Fang; Xu, He-Xiu] Air Force Engn Univ, Air & Missile Def Coll, Xian 710051, Shaanxi, Peoples R China.;[Liu, Haiwen] East China Jiaotong Univ, Sch Informat Engn, Nanchang 330013, Jiangxi, Peoples R China.;[Sun, Yunming] Adv Tech Dept, Key Lab Aeronaut Comp Tech, Xian 710175, Shaanxi, Peoples R China.
通讯机构：
[Xu, He-Xiu] H;Hengyang Normal Univ, Coll Phys & Elect Engn, Hengyang 421002, Peoples R China.
关键词：
Circular polarization;metasurface;orbital angular momentum (OAM);Pancharatnam-Berry phase (PB);vortex beam
摘要：
Vortex beams have been extensively realized using different approaches. Typically, the efficiency and bandwidth of a vortex beam are limited by impure copolarized components and the intrinsic dispersion of passive resonant structures. Here, we propose a strategy to generate wideband vortex beams by using a Pancharatnam-Berry metasurface in which two orthogonal reflections exhibit a broadband out-of-phase difference. To achieve this, a broadband strategy based on multimode operation and dispersion engineering methods was established. A dual-layer meta-atom is proposed; each layer comprises of five metallic dipoles, and the geometrical parameters are carefully adjusted to tune the resonant frequencies. Because the dipole orientations in each layer are orthogonal, the reflection responses under the two orthogonal polarizations can be independently engineered. Both numerical and experimental results indicate that our method not only enables a high-efficiency spiral beam conversion over a broad range of 6.95-18 GHz (>82%) but also causes a polarization-insensitive effect; thus, it can be adapted for any linear or circular polarization. © 1963-2012 IEEE.
语种：
英文
展开
Fabrication of Amine-Modified Magnetite-Electrochemically Reduced Graphene Oxide Nanocomposite Modified Glassy Carbon Electrode for Sensitive Dopamine Determination
作者：
He, Quanguo;Liu, Jun;Liu, Xiaopeng;Li, Guangli* ;Chen, Dongchu* ;...
期刊：
Nanomaterials ,2018年8(4):194-194 ISSN：2079-4991
通讯作者：
Li, Guangli;Chen, Dongchu
作者机构：
[He, Quanguo; Li, Guangli; Liu, Jun; Chen, Dongchu; Li, GL] Foshan Univ, Sch Mat Sci & Energy Engn, Foshan 528000, Peoples R China.;[He, Quanguo; Li, Guangli; Liang, Jing; Liu, Xiaopeng; Liu, Jun] Hunan Univ Technol, Coll Life Sci & Chem, Zhuzhou 412007, Peoples R China.;[Deng, Peihong] Hengyang Normal Univ, Dept Chem & Mat Sci, Hengyang 421008, Peoples R China.
通讯机构：
[Li, GL; Chen, DC] F;[Li, Guangli] H;Foshan Univ, Sch Mat Sci & Energy Engn, Foshan 528000, Peoples R China.;Hunan Univ Technol, Coll Life Sci & Chem, Zhuzhou 412007, Peoples R China.
关键词：
NH2-Fe3O4 nanoparticles;dopamine;electrochemical oxidation;modified electrode;reduced graphene oxide
摘要：
Amine-modified magnetite (NH(2)-Fe(3)O(4))/reduced graphene oxide nanocomposite modified glassy carbon electrodes (NH(2)-Fe(3)O(4)/RGO/GCEs) were developed for the sensitive detection of dopamine (DA). The NH(2)-Fe(3)O(4)/RGO/GCEs were fabricated using a drop-casting method followed by an electrochemical reduction process. The surface morphologies, microstructure and chemical compositions of the NH(2)-Fe(3)O(4) nanoparticles (NPs), reduced graphene oxide (RGO) sheets and NH(2)-Fe(3)O(4)/RGO nanocomposites were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-Ray diffraction (XRD) and Fourier-transform infrared (FTIR) spectroscopy. The electrochemical behaviors of DA on the bare and modified GCEs were investigated in phosphate buffer solution (PBS) by cyclic voltammetry (CV). Compared with bare electrode and RGO/GCE, the oxidation peak current (ipa) on the NH(2)-Fe(3)O(4)/RGO/GCE increase significantly, owing to the synergistic effect between NH(2)-Fe(3)O(4) NPs and RGO sheets. The oxidation peak currents (ipa) increase linearly with the concentrations of DA in the range of 1 x 10(-8) mol/L - 1 x 10(-7) mol/L, 1 x 10(-7) mol/L - 1 x 10(-6) mol/L and 1 x 10(-6) mol/L - 1 x 10(-5) mol/L. The detection limit is (4.0 +/- 0.36) x10(-9) mol/L (S/N = 3). Moreover, the response peak currents of DA were hardly interfered with the coexistence of ascorbic acid (AA) and uric acid (UA). The proposed NH(2)-Fe(3)O(4)/RGO/GCE is successfully applied to the detection of dopamine hydrochloride injections with satisfactory results. Together with low cost, facile operation, good selectivity and high sensitivity, the NH(2)-Fe(3)O(4)/RGO/GCEs have tremendous prospects for the detection of DA in various real samples.
语种：
英文
展开
Interference-assisted kaleidoscopic meta-plexer for arbitrary spin-wavefront manipulation
作者：
Xu, He-Xiu* ;Hu, Guangwei;Li, Ying;Han, Lei;Zhao, Jianlin;...
期刊：
光：科学与应用 ,2019年8(1):3 ISSN：2095-5545
通讯作者：
Xu, He-Xiu;Qiu, Cheng-Wei;Cui, Tie Jun
作者机构：
[Han, Lei; Xu, He-Xiu; Hu, Guangwei; Qiu, Cheng-Wei; Li, Ying; Xu, HX] Natl Univ Singapore, Dept Elect & Comp Engn, Singapore 117583, Singapore.;[Xu, He-Xiu; Wang, Guang-Ming; Yuan, Fang] Air Force Engn Univ, Air & Missile Def Coll, Xian 710051, Shaanxi, Peoples R China.;[Xu, He-Xiu; Ling, Xiaohui] Hengyang Normal Univ, Coll Phys & Elect Engn, Hunan Prov Key Lab Intelligent Informat Proc & Ap, Hengyang 421008, Peoples R China.;[Han, Lei; Zhao, Jianlin] Northwestern Polytech Univ, Sch Nat & Appl Sci, Xian 710072, Shaanxi, Peoples R China.;[Sun, Yunming] Adv Tech Dept, Key Lab Aeronaut Comp Tech, Xian 710075, Shaanxi, Peoples R China.
通讯机构：
[Xu, HX; Qiu, CW] N;[Xu, He-Xiu] A;[Xu, He-Xiu] H;[Cui, Tie Jun] S;Natl Univ Singapore, Dept Elect & Comp Engn, Singapore 117583, Singapore.
摘要：
Achieving simultaneous polarization and wavefront control, especially circular polarization with the auxiliary degree of freedom of light and spin angular momentum, is of fundamental importance in many optical applications. Interferences are typically undesirable in highly integrated photonic circuits and metasurfaces. Here, we propose an interference-assisted metasurface-multiplexer (meta-plexer) that counterintuitively exploits constructive and destructive interferences between hybrid meta-atoms and realizes independent spin-selective wavefront manipulation. Such kaleidoscopic meta-plexers are experimentally demonstrated via two types of single-layer spin-wavefront multiplexers that are composed of spatially rotated anisotropic meta-atoms. One type generates a spin-selective Bessel-beam wavefront for spin-down light and a low scattering cross-section for stealth for spin-up light. The other type demonstrates versatile control of the vortex wavefront, which is also characterized by the orbital angular momentum of light, with frequency-switchable numbers of beams under linearly polarized wave excitation. Our findings offer a distinct interference-assisted concept for realizing advanced multifunctional photonics with arbitrary and independent spin-wavefront features. A variety of applications can be readily anticipated in optical diodes, isolators, and spin-Hall meta-devices without cascading bulky optical elements. © 2019, The Author(s).
语种：
英文
展开
Chirality-Assisted High-Efficiency Metasurfaces with Independent Control of Phase, Amplitude, and Polarization
作者：
Xu, He-Xiu* ;Hu, Guangwei;Han, Lei;Jiang, Menghua;Huang, Yongjun;...
期刊：
Advanced Optical Materials ,2019年7(4):1801479- ISSN：2195-1071
通讯作者：
Xu, He-Xiu;Qiu, Cheng-Wei
作者机构：
[Xu, He-Xiu] Air Force Engn Univ, Air & Missile Def Coll, Xian 710051, Shaanxi, Peoples R China.;[Qiu, Cheng-Wei; Li, Ying; Han, Lei; Xu, He-Xiu; Xu, HX; Hu, Guangwei; Jiang, Menghua] Natl Univ Singapore, Dept Elect & Comp Engn, Singapore 117583, Singapore.;[Chen, Liezun; Xu, He-Xiu; Ling, Xiaohui] Hengyang Normal Univ, Coll Phys & Elect Engn, Hunan Prov Key Lab Intelligent Informat Proc & Ap, Hengyang 421002, Peoples R China.;[Han, Lei; Zhao, Jianlin] Northwestern Polytech Univ, Sch Nat & Appl Sci, Xian 710072, Shaanxi, Peoples R China.;[Huang, Yongjun] Univ Elect Sci & Technol China, Sch Informat & Commun Engn, Chengdu 611731, Sichuan, Peoples R China.
通讯机构：
[Xu, He-Xiu] A;[Xu, HX; Qiu, CW] N;[Xu, He-Xiu] H;Air Force Engn Univ, Air & Missile Def Coll, Xian 710051, Shaanxi, Peoples R China.;Natl Univ Singapore, Dept Elect & Comp Engn, Singapore 117583, Singapore.
关键词：
chirality-assisted metasurface;decoupling;self-accelerating beams;wavefront control
摘要：
Simultaneously independent control of phase, amplitude, and polarization is pivotal yet challenging for manipulating electromagnetic waves by transmissive metasurfaces. Huygens' metasurface affords a high-efficiency recipe primarily by engineering phase-only meta-atoms, restricting itself from realizing unprecedentedly complex functions of the transmission beam. Here, a 3D chirality-assisted metasurface concept relying on integrated magnetoelectric meta-atoms is proposed. It empowers the completely decoupled and arbitrary control of phase and amplitude at large incident angles and arbitrary polarizations. This strategy thus facilitates very sophisticated beam manipulations at close-to-unity cross-polarized efficiency via trilayer integrated resonators with mutual twist. The prescribed phase coverage can be determined by geometrical footprints of the unit cell, while the global azimuthal twist unlocks the capability of tuning amplitudes without affecting the phase. The concept and significance of it are validated to implement several proof-of-prototype demanding functionalities by thin metasurfaces of λ o /12, which generate self-accelerating diffraction-free Airy beams, lateral and axial dual focusing, and even specific multiplexed beam shaping, respectively. This finding opens up an alternative way in very fine control of light with minimalist complexity and advanced performance. It can stimulate novel and high-performance versatile photonic metadevices, thanks to the fully independent control of phase, amplitude, and polarization. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
语种：
英文
展开
Black Phosphorus Quantum Dots as an Efficient Saturable Absorber for Bound Soliton Operation in an Erbium Doped Fiber Laser
作者：
Wang, Zhiteng;Xu, Yanhua;Dhanabalan, Sathish Chander;Sophia, Joice;Zhao, Chujun;...
期刊：
IEEE Photonics Journal ,2016年8(5):1-10 ISSN：1943-0655
通讯作者：
Zhang, Han
作者机构：
[Xu, Changwen; Zhang, Han; Wang, Zhiteng; Xiang, Yuanjiang; Dhanabalan, Sathish Chander; Sophia, Joice] Shenzhen Univ, Shenzhen Key Lab Dimens Mat & Devices 2, Shenzhen Engn Lab Phosphorene & Optoelect, SZU NUS Collaborat Innovat Ctr Optoelect Sci & Te, Shenzhen 518060, Peoples R China.;[Xu, Changwen; Zhang, Han; Wang, Zhiteng; Xiang, Yuanjiang; Dhanabalan, Sathish Chander; Sophia, Joice] Shenzhen Univ, Key Lab Optoelect Devices & Syst, Minist Educ & Guangdong Prov, Shenzhen 518060, Peoples R China.;[Xu, Yanhua; Zhao, Chujun] Hunan Univ, Coll Phys & Microelect Sci, Minist Educ, Key Lab Micronano Optoelect Devices, Changsha 410082, Hunan, Peoples R China.;[Li, Jianqing] Macau Univ Sci & Technol, Fac Informat Technol, Ave Wai Long, Taipa, Macau, Peoples R China.;[Wang, Zhiteng] Hengyang Normal Univ, Dept Phys & Elect Informat, Hengyang 421008, Peoples R China.
通讯机构：
[Zhang, Han] S;Shenzhen Univ, Shenzhen Key Lab Dimens Mat & Devices 2, Shenzhen Engn Lab Phosphorene & Optoelect, SZU NUS Collaborat Innovat Ctr Optoelect Sci & Te, Shenzhen 518060, Peoples R China.;Shenzhen Univ, Key Lab Optoelect Devices & Syst, Minist Educ & Guangdong Prov, Shenzhen 518060, Peoples R China.
关键词：
Black phosphorus quantum dots (BPQDs);bound soliton;fiber laser;saturable absorber;mode-locking
摘要：
We have investigated the nonlinear and ultrafast photonics of chemically processed black phosphorus quantum dots (BPQDs) synthesized by the solvothermal treatment approach, with an average lateral size of about 2.48 +/- 0.4 nm. BPQDs exhibit optical saturable absorption measured by the balanced twin-detector measurement system at the telecommunication band and have been demonstrated for the generation of passively mode-locking operation in an erbium-doped fiber laser. Either two-pulse or three-pulse bound state of soliton pulse has been obtained, making the best use of the BPQDs-based saturable absorber. Our work suggests that BPQDs might be developed as an efficient optical saturable absorber for ultrafast photonics applications.
语种：
英文
展开
Electrochemical determination of bisphenol A in plastic bottled drinking water and canned beverages using a molecularly imprinted chitosan–graphene composite film modified electrode
作者：
Deng, Peihong* ;Xu, Zhifeng;Kuang, Yunfei
期刊：
Food Chemistry ,2014年157:490-497 ISSN：0308-8146
通讯作者：
Deng, Peihong
作者机构：
[Deng, Peihong; Xu, Zhifeng; Kuang, Yunfei] Hengyang Normal Univ, Dept Chem & Mat Sci, Hengyang 421008, Peoples R China.
通讯机构：
[Deng, Peihong] H;Hengyang Normal Univ, Dept Chem & Mat Sci, Hengyang 421008, Peoples R China.
关键词：
Imprinted electrochemical sensor;Bisphenol A;Graphene;Chitosan;Composite film;Voltammetric determination
摘要：
Herein, a novel electrochemical sensor based on an acetylene black paste electrode modified with molecularly imprinted chitosan-graphene composite film for sensitive and selective detection of bisphenol A (BPA) has been developed. Several important parameters controlling the performance of the sensor were investigated and optimised. The imprinted sensor offers a fast response and sensitive BPA quantification. Under the optimal conditions, a linear range from 8.0 nM to 1.0 μM and 1.0 to 20 μM for the detection of BPA was observed with the detection limit of 6.0 nM (S/N = 3). Meanwhile, the fabricated sensor showed excellent specific recognition to template molecule among the structural similarities and coexistence substances. Furthermore, this imprinted electrochemical sensor was successfully employed to detect BPA in plastic bottled drinking water and canned beverages. ©2014 Elsevier Ltd. All rights reserved.
语种：
英文
展开
Rapid recognition and determination of tryptophan by carbon nanotubes and molecularly imprinted polymer-modified glassy carbon electrode
作者：
Wu, Yiyong;Deng, Peihong* ;Tian, Yaling;Ding, Ziyu;Li, Guangli;...
期刊：
Bioelectrochemistry ,2020年131:107393 ISSN：1567-5394
通讯作者：
He, Quanguo;Deng, Peihong
作者机构：
[Li, Guangli; He, Quanguo; Tian, Yaling; Zuberi, Zavuga; Ding, Ziyu; Wu, Yiyong; Liu, Jun] Hunan Univ Technol, Sch Life Sci & Chem, Zhuzhou 412007, Peoples R China.;[He, Quanguo; Tian, Yaling; Ding, Ziyu; Deng, Peihong; Wu, Yiyong; Liu, Jun] Hengyang Normal Univ, Key Lab Funct Organometall Mat Hunan Prov Univ, Dept Chem & Mat Sci, Key Lab Funct Met Organ Cpds Hunan Prov, Hengyang 421008, Peoples R China.;[Zuberi, Zavuga] Nelson Mandela African Inst Sci & Technol, Sch Life Sci & Bioengn, POB 447, Arusha, Tanzania.;[Deng, Peihong] Hengyang Normal Univ, Hengyang 421008, Peoples R China.
通讯机构：
[He, Quanguo; Deng, Peihong] H;Hunan Univ Technol, Sch Life Sci & Chem, Zhuzhou 412007, Peoples R China.;Hengyang Normal Univ, Hengyang 421008, Peoples R China.
关键词：
Molecularly imprinting;Multi-walled carbon nanotubes;Tryptophan;Voltammetric sensor
摘要：
A tryptophan (Trp) molecularly imprinted electrochemical sensor was fabricated by drop-coating an imprinted chitosan film on the surface of a glassy carbon electrode modified with multi-walled carbon nanotubes (MIP-MWCNTs/GCE). The surface morphology and electrochemical properties of the MIP-MWCNTs/GCE were characterized by scanning electron microscopy (SEM) and cyclic voltammetry (CV), respectively. The formation of hydrogen bonds between the functional polymer and the template molecule was confirmed by infrared spectroscopy. The electrochemical performance of the MIP-MWCNTs/GCE with Trp showed that the signal of the oxidation current of Trp obtained with MIP-MWCNTs/GCE was significantly enhanced relative to that of the uncovered GCE, indicating that the modified electrode can accelerate electron transfer and has strong selectivity for Trp. The experimental conditions were optimized in parallel, and under the optimal conditions, the MIP-MWCNTs/GCE showed a good linear relationship between the Trp oxidation peak current and Trp concentrations in the ranges of 2.0nM-0.2muM, 0.2muM-10muM and 10muM-100muM The limit of detection (LOD) was 1.0nM (S/N=3), and the modified electrode had good reproducibility and stability. Finally, the MIP-MWCNTs/GCE was successfully applied to the determination of Trp in the human serum samples.
语种：
英文
展开
PREPARATION OF CU2O-REDUCED GRAPHENE NANOCOMPOSITE MODIFIED ELECTRODES TOWARDS ULTRASENSITIVE DOPAMINE DETECTION
作者：
He, Quanguo;Liu, Jun;Liu, Xiaopeng;Li, Guangli* ;Deng, Peihong* ;...
期刊：
Sensors ,2018年18(1):199 ISSN：1424-3210
通讯作者：
Li, Guangli;Deng, Peihong
作者机构：
[He, Quanguo; Li, Guangli; Liang, Jing; Liu, Xiaopeng; Liu, Jun] Hunan Univ Technol, Sch Life Sci & Chem, Hunan Key Lab Biomed Nanomat & Devices, Zhuzhou 412007, Peoples R China.;[Deng, Peihong] Hengyang Normal Univ, Dept Chem & Mat Sci, Hengyang 421008, Peoples R China.
通讯机构：
[Li, Guangli; Deng, Peihong] H;Hunan Univ Technol, Sch Life Sci & Chem, Hunan Key Lab Biomed Nanomat & Devices, Zhuzhou 412007, Peoples R China.;Hengyang Normal Univ, Dept Chem & Mat Sci, Hengyang 421008, Peoples R China.
关键词：
Cu2O nanoparticles;dopamine detection;electrochemical oxidation;modified electrode;reduced graphene oxide
摘要：
Cu<inf>2</inf>O-reduced graphene oxide nanocomposite (Cu<inf>2</inf>O-RGO) was used to modify glassy carbon electrodes (GCE), and applied for the determination of dopamine (DA). The microstructure of Cu<inf>2</inf>O-RGO nanocomposite material was characterized by scanning electron microscope. Then the electrochemical reduction condition for preparing Cu<inf>2</inf>O-RGO/GCE and experimental conditions for determining DA were further optimized. The electrochemical behaviors of DA on the bare electrode, RGO- and Cu<inf>2</inf>O-RGO-modified electrodes were also investigated using cyclic voltammetry in phosphate-buffered saline solution (PBS, pH 3.5). The results show that the oxidation peaks of ascorbic acid (AA), dopamine (DA), and uric acid (UA) could be well separated and the peak-to-peak separations are 204 mV (AA-DA) and 144 mV (DA-UA), respectively. Moreover, the linear response ranges for the determination of 1 ×10<sup>-</sup><sup>8</sup>mol/L~1 ×10<sup>-</sup><sup>6</sup>mol/L and 1 ×10<sup>-</sup><sup>6</sup>mol/L~8 ×10<sup>-</sup><sup>5</sup>mol/L with the detection limit 6.0 ×10<sup>-</sup><sup>9</sup>mol/L (S/N = 3). The proposed Cu2O-RGO/GCE was further applied to the determination of DA in dopamine hydrochloride injections with satisfactory results.<br/> ©2018 by the authors. Licensee MDPI, Basel, Switzerland.
语种：
英文
展开
Highly Efficient and Stable Self-Powered Ultraviolet and Deep-Blue Photodetector Based on Cs2AgBiBr6/SnO2 Heterojunction
作者：
Wu, Cuncun;Du, Bowen;Luo, Wei;Liu, Yang;Li, Tieyi;...
期刊：
Advanced Optical Materials ,2018年6(22):1800811- ISSN：2195-1071
通讯作者：
Wang, Shufeng;Xiao, Lixin;Chen, Yanxue
作者机构：
[Wu, Cuncun; Fang, Zheyu; Li, Tieyi; Guo, Xuan; Liu, Yang; Chen, Zhijian; Wang, Shufeng; Du, Bowen; Ting, Hungkit; Xiao, Lixin; Wang, Duo; Luo, Wei; Wang, SF] Peking Univ, State Key Lab Mesoscop Phys, Beijing 100871, Peoples R China.;[Wu, Cuncun; Fang, Zheyu; Li, Tieyi; Guo, Xuan; Liu, Yang; Chen, Zhijian; Wang, Shufeng; Du, Bowen; Ting, Hungkit; Xiao, Lixin; Wang, Duo; Luo, Wei; Wang, SF] Peking Univ, Dept Phys, Beijing 100871, Peoples R China.;[Chen, Yanxue] Shandong Univ, Sch Phys, Jinan 250100, Shandong, Peoples R China.;[Chen, Yanxue] Shandong Univ, State Key Lab Crystal Mat, Jinan 250100, Shandong, Peoples R China.;[Xiao, Lixin] Hengyang Normal Univ, Coll Phys & Elect Engn, Hengyang 421008, Hunan, Peoples R China.
通讯机构：
[Wang, SF; Xiao, LX] P;[Chen, Yanxue] S;[Xiao, Lixin] H;Peking Univ, State Key Lab Mesoscop Phys, Beijing 100871, Peoples R China.;Peking Univ, Dept Phys, Beijing 100871, Peoples R China.
关键词：
Cs2AgBiBr6/SnO2 heterojunction;double perovskite Cs2AgBiBr6;responsivity;ultraviolet photodetectors
摘要：
Ultraviolet (UV) photodetectors with high responsivity and fast response are crucial for practical applications. Double perovskite Cs 2 AgBiBr 6 has emerged as a promising optoelectronic material due to its excellent physics and photoelectric properties. However, no work is reported based on its film for photodetector applications. Herein, an ITO/SnO 2 /Cs 2 AgBiBr 6 /Au hole-transport layer free planar heterojunction device is fabricated for photodetector application. The device is self-powered with two responsivity peaks at 350 and 435 nm, which is suitable for ultraviolet-A (320–400 nm) and deep-blue light detecting. A high responsivity of 0.11 A W −1 at 350 nm and a quick response time of less than 3 ms are obtained, which is significantly higher than other semiconductor oxide heterojunction-based UV detectors. More importantly, the stability is significantly better than most of the hybrid perovskite photodetectors reported so far. Its photocurrent shows no obvious degradation after more than 6 months storage in ambient conditions without any encapsulation. Consequently, the utilization of Cs 2 AgBiBr 6 film is a practical approach for high performance, large-area lead-free perovskite photodetector applications. For the mechanism, it is found that photogenerated carriers in Cs 2 AgBiBr 6 film are separated at the Cs 2 AgBiBr 6 /SnO 2 heterojunction interface by its built-in field. The low toxicity and high stability of this double perovskite active layer make it very promising for practical applications. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
语种：
英文
展开
Electrochemical behavior and voltammetric determination of vanillin based on an acetylene black paste electrode modified with graphene–polyvinylpyrrolidone composite film
作者：
Deng, Peihong* ;Xu, Zhifeng;Zeng, Rongying;Ding, Chunxia
期刊：
Food Chemistry ,2015年180:156-163 ISSN：0308-8146
通讯作者：
Deng, Peihong
作者机构：
[Deng, Peihong; Xu, Zhifeng; Zeng, Rongying] Hengyang Normal Univ, Dept Chem & Mat Sci, Hengyang 421008, Peoples R China.;[Zeng, Rongying] Hunan Agr Univ, Coll Resource & Environm, Changsha 410128, Hunan, Peoples R China.;[Ding, Chunxia] Hunan Agr Univ, Coll Sci, Changsha 410128, Hunan, Peoples R China.
通讯机构：
[Deng, Peihong] H;Hengyang Normal Univ, Dept Chem & Mat Sci, Hengyang 421008, Peoples R China.
关键词：
Electrochemical behavior;Electrochemical sensor;Graphene-polyvinylpyrrolidone composite film;Vanillin;Voltammetric determination
摘要：
The graphene-polyvinylpyrrolidone composite film modified acetylene black paste electrode (GR-PVP/ABPE) was fabricated and used to determine vanillin. In 0.1 M H<inf>3</inf>PO<inf>4</inf> solution, the oxidation peak current of vanillin increased significantly at GR-PVP/ABPE compared with bare ABPE, PVP/ABPE and GR/ABPE. The oxidation mechanism was discussed. The experimental conditions that exert influence on the voltammetric determination of vanillin, such as supporting electrolytes, pH values, accumulation potential and accumulation time, were optimized. Besides, the interference, repeatability, reproducibility and stability measurements were also evaluated. Under the optimal experimental conditions, the oxidation peak current was proportional to vanillin concentration in the range of 0.02-2.0 μM, 2.0-40 μM and 40-100 μM. The detection limit was 10 nM. This sensor was used successfully for vanillin determination in various food samples. ©2015 Elsevier Ltd. All rights reserved.
语种：
英文
展开
Facile synthesis of Ag@Cu2 O heterogeneous nanocrystals decorated N-doped reduced graphene oxide with enhanced electrocatalytic activity for ultrasensitive detection of H2 O2
作者：
Li, Junhua;Jiang, Jianbo;Xu, Zhifeng;Liu, Mengqin;Tang, Siping;...
期刊：
Sensors and Actuators B-Chemical ,2018年260:529-540 ISSN：0925-4005
通讯作者：
Qian, Dong
作者机构：
[Tang, Siping; Liu, Mengqin; Xu, Zhifeng; Li, Junhua] Hengyang Normal Univ, Coll Chem & Mat Sci, Hengyang 421008, Peoples R China.;[Li, Junhua; Jiang, Jianbo; Qian, Dong] Cent S Univ, Coll Chem & Chem Engn, Changsha 410083, Hunan, Peoples R China.;[Li, Junhua] Hengyang Normal Univ, Key Lab Funct Met Organ Cpds Hunan Prov, Key Lab Funct Organometall Mat, Hengyang 421008, Peoples R China.;[Jiang, Jianbo] Jishou Univ, Coll Chem & Chem Engn, Jishou 416000, Peoples R China.;[Yang, Chunming] Hunan Normal Univ, Coll Chem & Chem Engn, Changsha 410081, Hunan, Peoples R China.
通讯机构：
[Qian, Dong] C;Cent S Univ, Coll Chem & Chem Engn, Changsha 410083, Hunan, Peoples R China.
关键词：
Hydrogen peroxide;Nonenzymatic sensor;Ultrasensitive detection;Ag@Cu2O nanocrystals;N-doped reduced graphene oxide
摘要：
A nanohybrid composed of Ag@Cu2O heterogeneous nanocrystals supported on N-doped reduced graphene oxide (Ag@Cu2O/N-RGO) has been synthesized by a simple wet-chemical method. The resultant composite consists of N-RGO sheets fully and homogeneously coated with a dense layer of Ag@Cu2O nanocrystals. Both Ag and N-RGO are in direct contact with Cu2O, and Ag nanoparticles with sizes of 2-5 nm are mainly deposited on the surface of Cu2O cubes (edge length of 500 nm). The electrochemical studies reveal that the ternary Ag@Cu2O/N-RGO composite exhibit significantly enhanced electrocatalytic activity for H2O2 sensing compared with either the single component (N-RGO) or two component systems (Cu2O/N-RGO and Ag/N-RGO), which is mainly due to the synergetic catalysis of the ternary system. The nonenzymatic sensor based on Ag@Cu2O/N-RGO composite shows overwhelmingly superior comprehensive performance for the H2O2 detection over the documented Ag-based sensors. More specifically, it displays a rapid response (10 s) to H2O2 over a wide linear range of 54-700 nM with a high sensitivity of 1298.3 mu A mM(-1) cm(-2) and a low detection limit of 10 nM. Moreover, the sensor also exhibits the preferable selectivity in the presence of biologically coactive compounds accompanied with long-term stability and good reproducibility. (C) 2018 Elsevier B.V. All rights reserved.
语种：
英文
展开
