作者机构：
[Yuxue Mo] College of Physics and Electronic Engineering, Hengyang Normal University, Hengyang, 421002 P. R. China;[Xuan Zhou; Fang Yu; Liling Liao; Xinru Yong; Fangming Zhang; Dongyang Li; Qian Zhou; Haiqing Zhou] Key Laboratory of Low-Dimensional Quantum Structures and Quantum Control of Ministry of Education, Key Laboratory for Matter Microstructure and Function of Hunan Province, Department of Physics and Synergetic Innovation Center for Quantum Effects and Applications, Hunan Normal University, Changsha, 410081 P. R. China;[Tian Sheng] College of Chemistry and Materials Science, Anhui Normal University, Wuhu, 241000 P. R. China
通讯机构：
[Fang Yu; Haiqing Zhou] K;[Tian Sheng] C;Key Laboratory of Low-Dimensional Quantum Structures and Quantum Control of Ministry of Education, Key Laboratory for Matter Microstructure and Function of Hunan Province, Department of Physics and Synergetic Innovation Center for Quantum Effects and Applications, Hunan Normal University, Changsha, 410081 P. R. China<&wdkj&>College of Chemistry and Materials Science, Anhui Normal University, Wuhu, 241000 P. R. China
关键词：
bifunctional water splitting;cobalt nitride;heterostructures;iron phosphide;large current density
摘要：
Self‐supported Fe2P/Co2N porous heterostructure arrays are in situ constructed with abundant iron sites exposing at the surface, which presents superb bifunctional catalytic activity for hydrogen and oxygen evolution reactions in base, substantially expediting the overall water splitting at 500 mA cm−2 with only 1.663 V, prominently superior to IrO2(+)//Pt(−) coupled electrodes and most of non‐noble bifunctional electrocatalysts. Abstract Alkaline water electrolysis is a commercially viable technology for green H2 production using renewable electricity from intermittent solar or wind energy, but very few non‐noble bifunctional catalysts simultaneously exhibit superb catalytic efficiency and stability at large current densities for hydrogen and oxygen evolution reactions (HER and OER, respectively), especially for iron‐based catalysts. Given that iron is the most abundant and least expensive transition metal, iron‐based compounds are very attractive low‐cost targets as active electrocatalysts for bifunctional water splitting with large‐current durability. Herein, the in situ construction of a self‐supported Fe2P/Co2N porous heterostructure arrays possessing superb bifunctional catalytic activity in base is reported, featured by low overpotentials of 131 and 283 mV to attain a current density of 500 mA cm−2 for HER and OER, respectively, outperforming most of non‐noble bifunctional electrocatalysts reported hitherto. Particularly, this hybrid catalyst also displays an excellent overall water splitting activity, requiring low voltages of 1.561 and 1.663 V to attain 100 and 500 mA cm−2 with excellent durability in 1 m KOH, respectively. Most importantly, the catalyst is stable for >120 h, even when the current density is 500 mA cm−2, which is prominently superior to IrO2(+)//Pt(−) coupled noble electrodes, and is among the very best bifunctional catalysts reported thus far. Detailed theoretical calculations reveal that the interfacial interaction between Fe2P and Co2N can further improve the H* binding energy at the iron sites.
通讯机构：
[Xiaohui Ling] L;Laboratory for Spin-Orbit Photonics, College of Physics and Electronic Engineering, Hengyang Normal University, Hengyang 421002, People's Republic of China
关键词：
angular momentum;photonic orbital Hall effect;vortex phase;mode decomposition
摘要：
The photonic orbital Hall effect (POHE) refers to the vortex-dependent beam shifts, which is generally believed to result from the conversion of intrinsic orbital angular momentum (IOAM) to extrinsic orbital angular momentum (EOAM). However, the physical mechanism of the POHE, such as how the IOAM is converted to the EOAM, remains further elucidation. In this paper, we re-examine the POHE of a vortex beam with additional IOAM illuminating at an optically thin slab by means of vortex mode decomposition. By considering the competition and coupling between the radial and azimuthal vortex harmonics of the abnormal mode in the transmitted beam, it is found that the underlying mechanism of the POHE is in fact a spin-to-orbital angular momentum (OAM) conversion process. And the IOAM carried by the incident beam is directly superimposed on the OAM obtained during the conversion. Our findings not only offer an alternative perspective for understanding the POHE, but also exhibit application potential in orbit-orbit and spin-orbit optical components.
作者机构：
[Changyou Luo] Department of Physics and Electronic Information Science, Hengyang Normal University, Hengyang, China;[Xiaoyu Dai; Yuanjiang Xiang] Key Laboratory for Micro-/Nano-Optoelectronic Devices of Ministry of Education, College of Physics and Microelectronic Science, Hunan University, Changsha, China;[Yongqiang Kang] Institute of Solid State Physics, Shanxi Datong University, Datong, Shanxi, China
关键词：
Goos-Hänchen shift;Coherent control
摘要：
In this paper, we proposed a cavity containing an intracavity medium of five-level double-ladder-type atoms with electromagnetically induced transparency to enhance Goos- Hänchen shifts of reflected and transmitted light beams. The dependence of the Goos-Hänchen shifts has been analyzed. It is shown that Goos-Hänchen shifts can be controlled by modifying the intensity and detuning of the coherent control field without changing material and the structure of the dielectric interface. This work has considerable potential for applications such as optical devices in information processing, flexible optical-beam steering and alignment, optical sensors and optical switches.
作者机构：
[Huang, F. F.; Sun, L. Z.] Xiangtan Univ, Sch Mat Sci & Engn, Hunan Prov Key Lab Thin Film Mat & Devices, Xiangtan 411105, Peoples R China.;[Ma, Z. S.; He, S. D.; Zhou, P.; Li, W. Q.] Xiangtan Univ, Sch Mat Sci & Engn, Xiangtan 411105, Peoples R China.;[Tan, R.] Hengyang Normal Univ, Coll Phys & Elect Engn, Hengyang 421002, Peoples R China.
摘要：
Second-order topological phases in artificial systems have been extensively studied, but studies in the phonons of atomic materials are limited. In this paper, we propose that phononic second-order topological phase exists in C3N , a previously synthesized and intensively investigated two-dimensional material. Its nontrivial phase arises from the mismatch between the Wannier centers of the out-of-plane phonon modes and the atomic positions. Using a simplified force constant model, we find that gapped edge modes and in-gap corner modes only exist on the structures with broken pure-carbon-ring terminations, and this unexpected phenomenon can be explained by the electronlike filling anomaly for phonons. Further calculations reveal that these corner modes are robust to external disturbances. The nontrivial phononic phase in C3N provides an avenue in crystalline materials to explore higher-order topological phases in Bose systems.
作者机构：
[Liang, Xijie; Ma, Fengkai; Guan, Heyuan; Xie, Manyan; Lu, Huihui; Luo, Kaiwen; He, Zhigang; Chen, Junteng; Yang, Tiefeng] Guangdong Provincial Key Laboratory of Optical Fiber Sensing and Communications, Jinan University, Guangzhou 510632, China;[Xie, Manyan; Lu, Huihui; Luo, Kaiwen; Chen, Junteng] Key Laboratory of Optoelectronic Information and Sensing Technologies of Guangdong Higher Education Institutes, Jinan University, Guangzhou 510632, China;[An, Ran] Institute of Fluid Physics, China Academy of Engineering Physics, Mianyang 621900, China;[Ma, Liang] College of Physics and Electronic Engineering, Hengyang Normal University, Hengyang 421008, China
摘要：
High-performance photodetectors hold promising potential in optical communication and imaging systems. However, conventional counterparts are suffering narrow detection range, high power consumption, and poor polarization sensitivity. Characteristics originating from switchable polarization in ferroelectrics can be used to optimize the photo-to-electric procedure and improve the photodetection performance. In this regard, we constructed a configuration by integrating 2-dimensional molybdenum disulfide (MoS(2)) with ferroelectric lithium niobate (LiNbO(3)), resulting in the MoS(2)/LiNbO(3) heterostructured photodetector. Benefiting from the pyroelectric effect of LiNbO(3), the limitation of bandgap on the detection range can be broken, thus broadening the response band of the detector to 365 to 1,064 nm, as well as enabling the self-powered characteristic. Meanwhile, high carrier mobility and decent light absorbance of MoS(2) introduce robust light-matter interactions with the underlying LiNbO(3), leading to ultrafast rise/fall times of ≈150 μs/250 μs and switching ratios of up to ≈190. Moreover, the highest responsivity, specific detectivity, and external quantum efficiency achieved were 17.3 A·W(-1), 4.3 × 10(11) Jones, and 4,645.78%, respectively. Furthermore, because of the anisotropy of the spontaneous-polarized LiNbO(3) substrate, the photocurrent of the device achieved a dichroic ratio of 7.42, comparing favorably to most MoS(2)-based photodetectors. This work demonstrates the integration potential between ferroelectric LiNbO(3) and 2-dimensional materials for high-performance photodetection.
摘要：
Graphene is always used to construct two-dimensional (2D) van der Waals (vdW) heterostructures due to its excellent performance. Hydrogenated phosphorus carbides (HPC or PCH), as novel 2D carbon-based materials, are predicted to be potential for nanoelectronics and optoelectronics. Herein, we explore the electronic prop-erties of vdW heterostructure of graphene and hydrogenated phosphorus carbides under both strain and electric field by using first-principles calculations. The results demonstrate that the Schottky barrier height (SBH) and band gap of the heterostructures can be effectively modulated by in-plane uniaxial or biaxial strain, but the Schottky contact type (n-type or p-type) could not be modified by the strain alone in the investigated range (from-10% to 10%). Interestingly, when the strain and electric field are simultaneously applied to the heterostructure, not only the SBH and band gap but also the Schottky contact type could be modulated effectively. The results open a new avenue for design of 2D carbon-based nanoelectronic and optoelectronic devices.
通讯机构：
[Yanliang Tan] C;College of Physics and Electronic Engineering , Hengyang Normal University, Hengyang, Hunan Province 421008, China
摘要：
Radon-222 (Rn-222) exhalation rate is vital for estimating radiation risk from many kinds of materials. AlphaGUARD measures the radon concentration based on the ionization chamber principle, which is currently recognized as a reference instrument to measure radon. In China, measurements of radon exhalation rate are performed by AlphaGUARD operated in flow-through mode on a reference device to verify measurement accuracy. These measurements are performed in both open and closed loop. AlphaGUARD can fast rapidly the variation of the radon concentration in the chamber, which is tightly pressed against the surface of the medium to accumulate the exhaled radon. When the model is used to obtain the radon exhalation rate, the radon exhalation rates obtained by nonlinear data fitting on the measured radon concentrations are similar to the reference value of the device. The difference of radon exhalation rate values of six measurements is small.
摘要：
Although the d-band center theory can well describe the interaction between gas molecules and transition metal surfaces, the detailed reaction process and specific adsorption conditions are unclear. Hence, in this work, we systematically studied the adsorption mechanism, adsorption conditions, and recovery time of NO and NO2 molecules on different transition metals (Cu, Ag, Au, Ni, Pd, Pt, Rh, Ru, Tc, Mo, Nb, and Zr) surfaces by first-principles. The results indicated that the charge transfers from the dz2, dxz, and dyz orbitals of substrate atoms to the HOMOs/LUMOs of NO and NO2. Moreover, we demonstrate that the interaction orbitals between the NO/NO2 and the metal atoms excellently correspond with the match of energy level and parity, and the maximum overlap of the orbital wave function. Interestingly, the excellent linear scaling between charge transfer and the d-band center, work function, and matrix element (V-ad(2)) of metals has been confirmed. Specifically, the different recovery times of these systems at different temperatures were explored. Our results can provide a feasible way for exploring gas-sensitive materials in the experiments.
摘要：
The linear behavior of the dominant unstable mode (m = 2, n = 1) and its high order harmonics (m = 2n, n >= 2) are numerically investigated in a reversed magnetic shear cylindrical plasma with two q = 2 rational surfaces on the basis of the non-reduced magnetohydrodynamics (MHD) equations. The results show that with low beta (beta is defined as the ratio of plasma pressure to magnetic field pressure), the dominant mode is a classical double tearing mode (DTM). However, when the beta is sufficiently large, the mode is driven mainly by plasma pressure. In such a case, both the linear growth rate and mode structures are strongly affected by pressure, while almost independent of the resistivity. This means that the dominant mode undergoes a transition from DTM to pressure-driven mode with the increase of pressure, which is consistent with the experimental result in ASDEX Upgrade. The simulations also show that the distance between two rational surfaces has an important influence on the pressure needed in mode transition. The larger the distance between two rational surfaces, the larger the pressure for driving the mode transition is. Motivated by the phenomena that the high-m modes may dominate over low-m modes at small inter-resonance distance, the high-m modes with different pressures and q profiles are studied too.
作者机构：
[Tan, Yanliang; Mo, Yuxue; Deng, Yanhong; Tang, Yuxiang; Zhou, Wanying] Hengyang Normal Univ, Coll Phys & Elect Engn, Henghua Rd 16, Hengyang City 421002, Hunan Province, Peoples R China.;[Lin, Jin-Xia] Xiamen Univ, State Key Lab Phys Chem Solid Surface, Coll Chem & Chem Engn, Xiamen 361005, Peoples R China.;[Sheng, Tian] Anhui Normal Univ, Coll Chem & Mat Sci, Wuhu 241000, Peoples R China.
通讯机构：
[Mo, YX ] H;Hengyang Normal Univ, Coll Phys & Elect Engn, Henghua Rd 16, Hengyang City 421002, Hunan Province, Peoples R China.
关键词：
Lithium-sulfur batteries;Strong adsorption effect;First principal calculation;High sulfur loading
摘要：
The lithium-sulfur (Li-S) batteries have achieved important developments, but still suffer from some main intrinsic disadvantages, such as the dissolution and diffusion of the lithium polysulfides (LiPSs). In response, here we develop a Mo2C/MoO3 heterostructure as the interlayer to restrain the leakage and migration of LiPSs. Owing to its good conductivity and excellent electronic transport, this heterostructure can perform excellently as an ideal carrier for providing reduction reaction sites of LiPSs conversion, thus greatly improving the electrochemical properties of Mo2C/MoO3 for Li-S batteries. The resultant Mo2C/MoO3 electrodes can deliver a high specific capacity of 1346 mAh g- 1 at 0.1C and long-term cycling stability (660 mAh g- 1 after 800 cycles at 2C) with a low capacity decay rate of 0.05% per cycle, indicating high sulfur utilization and fast kinetic conversion of LiPSs and Li2S. When the sulfur loading is increased to 4.34 mg cm-2, the initial discharge capacity and areal capacity of the Mo2C/MoO3 electrode at 0.1C is still up to 1405 mAh g- 1 and 6.1 mAh cm-2 with a coulombic efficiency of 99% in the first cycle, indicating faster LiPSs conversion. First-principle calculations reveal that the as-synthesized LiPSs species are selectively adsorbed on the MoO3 (001) and Mo2C (001) surface. This work provides an alternative strategy toward high-performance Li-S battery with high sulfur loading.
通讯机构：
[Fang Yu; Haiqing Zhou] K;Key Laboratory of Low-Dimensional Quantum Structures and Quantum Control of Ministry of Education, Key Laboratory for Matter Microstructure and Function of Hunan Province, Department of Physics and Synergetic Innovation Center for Quantum Effects and Applications, Hunan Normal University, Changsha 410081, China
关键词：
bifunctional water splitting;electrocatalyst;non-noble metal;porous material;seawater splitting
摘要：
Given the abundant reserves of seawater and the scarcity of freshwater, real seawater electrolysis is a more economically appealing technology for hydrogen production relative to orthodox freshwater electrolysis. However, this technology is greatly precluded by the undesirable chlorine oxidation reaction and severe chloride corrosion at the anode, further restricting the catalytic efficiency of overall seawater splitting. Herein, a feasible strategy by engineering multifunctional collaborative catalytic interfaces is reported to develop porous metal nitride/phosphide heterostructure arrays anchoring on conductive Ni2P surfaces with affluent iron sites. Collaborative catalytic interfaces among iron phosphide, bimetallic nitride, and porous Ni2P supports play a positive role in improving water adsorption/dissociation and hydrogen adsorption behaviors of active Fe sites evidenced by theoretical calculations for hydrogen evolution reactions, and enhancing oxygenated species adsorption and nitrate-rich passivating layers resistant to chloride corrosion for oxygen evolution reaction, thus cooperatively propelling high-performance bifunctional seawater splitting. The resultant material Fe2P/Ni1.5Co1.5N/Ni2P performs excellently as a self-standing bifunctional catalyst for alkaline seawater splitting. It requires extremely low cell voltages of 1.624 and 1.742 V to afford current densities of 100 and 500 mA/cm2 in 1 M KOH seawater electrolytes, respectively, along with superior long-term stability, outperforming nearly all the ever-reported non-noble bifunctional electrocatalysts and benchmark Pt/IrO2 coupled electrodes for freshwater/seawater electrolysis. This work presents an effective strategy for greatly enhancing the catalytic efficiency of non-noble catalysts toward green hydrogen production from seawater electrolysis.
摘要：
The U.S. Environmental Protection Agency established the maximum contaminant level limit for radon concentration in drinking water as 11.1 Bq L(-1). A new device based on the bubbling method with a 290mL sample bottle was designed for intermittent continuous measurement of water radon concentration. A STM32 is used to control the switch of the water pump and the valves. The Water-Radon-Measurement software written in C# is to connect RAD7 and calculate the water radon concentration automatically.
摘要：
Differential analysis is a vital tool for evaluating the security of cryptography algorithms. There has been a growing interest in the differential distinguisher based on deep learning. Various neural network models have been created to increase the accuracy of distinguishing between ciphertext and random sequences. However, few studies have focused on differential analysis at the design stage of cryptographic algorithms. This paper presents an appropriate model for differential analysis of block ciphers. The model is similar to multilayer perceptron (MLP) models in simplicity and clarity. It also introduces a shortcut connection that enables one to learn more information about the differential analysis dataset. The model is used to predict the minimum number of active S-boxes (AS), linking differential analysis results to algorithm features. This model and two classical neural network models are compared under fair experimental conditions. The findings indicate that our model predicts the AS values with an accuracy of 97%. It can effectively predict the results of differential analysis. In addition, the differential analysis dataset is constructed for SPN structure cryptographic algorithms. It can be used for further differential analysis studies based on deep learning.
关键词：
Aqueous zinc ion batteries;Zinc anode;Separator modification;Graphite fluoride
摘要：
Aqueous zinc ion batteries (AZIBs) are considered as a promising candidate for large-scale energy storage due to its superior energy density, high specific energy, environmental friendliness and low cost. However, the dendrite growth and side reaction of zinc anode severely hinder its stability and availability. Herein, commercial glass fiber separators are modified by graphite fluoride nanoflakes via vacuum filtration (denoted as GFNs-PVDF@GF) to reinforce Zn metal anode. The GFNs-PVDF@GF separator acts as an efficient ions transport modulator to homogenize Zn2+ transport and suppress SO42− flux due to strong zinc affinity and electronegativity of GFNs, thereby restraining the growth of zinc dendrite and the formation of byproducts. Accordingly, the Zn||Zn symmetric cell harvests a stable and reversible cycling for 1800 h at 1 mA cm−2 and operates at 5 mA cm−2 for over 900 h. The assembled Zn||MnO2 full cells deliver a capacity retention of 92% after 200 cycles at 1 A g−1. Our results provide a simple and effective strategy of improving stability of zinc anode for high-performance AZIBs.
摘要：
Reachable Zinc ion batteries (ZIBs) are regarded as promising large scale energy storge systems because of their advantages of high safety, high energy density (high volumetric capacity), and economic benefits. However, ZIBs suffer from of lack of suitable cathode materials with high capacity and long stability of circulation. In addition, conventional coating process to prepare cathode with binder (PVDF/PTFE et al.) will not only reduce active material loading but also hinder ion transmission. Hence, a simple binder-free cathode prepare process was proposed. We use laser irradiation the Mn7O13.5H2O/graphene oxide cathode. The laser irradiation will induce vacancy defect in the Mn7O13.5H2O, leading to more active contact sites. Finally, the prepared materials achieve an ultra-high specific capacity of 411.6 mAh g-1 (0.2 A g- 1), an excellent rate performance (176.3 mAh g-1 at a current density of 5 A g-1), and a satisfactory capacity retention rate of 90.1% after long 3500 cycles at 2 A g-1. The assembled all-in-one architecture battery has a fair specific capacity of 177.3 mAh g-1 at the current density of 2 A g-1. This work opens up a new horizon for conveniently preparing binder-free cathode materials with defects for high energy density and long cycle life.
作者机构：
[Yuan, Ji-Bing; Zhang, Bo; Song, Ya-Ju; Yuan, JB; Tang, Shi-Qing; Wang, Xin-Wen] Hengyang Normal Univ, Key Lab Optoelect Control & Detect Technol Univ Hu, Hengyang 421002, Peoples R China.;[Yuan, Ji-Bing; Zhang, Bo; Song, Ya-Ju; Yuan, JB; Tang, Shi-Qing] Hengyang Normal Univ, Coll Phys & Elect Engn, Hengyang 421002, Peoples R China.;[Kuang, Le -Man; Kuang, LM] Hunan Normal Univ, Key Lab Low Dimens Quantum Struct & Quantum Contro, Minist Educ, Changsha 410081, Peoples R China.;[Kuang, Le -Man; Kuang, LM] Hunan Normal Univ, Dept Phys, Changsha 410081, Peoples R China.;[Kuang, Le -Man; Kuang, LM] Zhengzhou Univ Light Ind, Synerget Innovat Acad Quantum Sci & Technol, Zhengzhou 450002, Peoples R China.
通讯机构：
[Kuang, LM ; Yuan, JB ] H;Hengyang Normal Univ, Key Lab Optoelect Control & Detect Technol Univ Hu, Hengyang 421002, Peoples R China.;Hengyang Normal Univ, Coll Phys & Elect Engn, Hengyang 421002, Peoples R China.;Hunan Normal Univ, Key Lab Low Dimens Quantum Struct & Quantum Contro, Minist Educ, Changsha 410081, Peoples R China.;Hunan Normal Univ, Dept Phys, Changsha 410081, Peoples R China.
摘要：
We propose a theoretical scheme for quantum sensing of temperature close to absolute zero in a quasi-one-dimensional Bose-Einstein condensate (BEC). In our scheme, a single-atom impurity qubit is used as a temperature sensor. We investigate the sensitivity of the single-atom sensor in estimating the temperature of the BEC. We demonstrate that the sensitivity of the temperature sensor can saturate the quantum Cramér-Rao bound by means of measuring quantum coherence of the probe qubit. We study the temperature sensing performance by using quantum signal-to-noise ratio (QSNR). It is indicated that there is an optimal encoding time at which the QSNR can reach its maximum in the full-temperature regime. In particular, we find that the QSNR reaches a finite upper bound in the weak coupling regime even when the temperature is close to absolute zero, which implies that the sensing-error-divergence problem is avoided in our scheme. Our work opens a way for quantum sensing of temperature close to absolute zero in the BEC.
摘要：
A “two in one” interface engineering is developed to improve the reversibility of Zn anode, in which multi‐functional Zn5(NO3)2(OH)8·2H2O layer and preferential Zn (002) texture are constructed simultaneously.Besides inhibiting water‐induced side reactions, , such complementary interface not only can accelerate the desolvation process of [Zn (H2O)6]2+ and transfer kinetics of Zn2+ ions, but also guide Zn (002)‐preferred orientation deposition. . Abstract Advanced interfacial engineering performs a forceful modulation effect on Zn2+ plating/stripping with simultaneous inhibition of hydrogen evolution reaction, chemical corrosion, and dendrite growth, which is responsible for high reversibility of Zn anode. Herein, a “two in one” interface engineering is developed to improve the reversibility of Zn anode, in which multi‐functional Zn5(NO3)2(OH)8·2H2O layer and preferential Zn (002) texture are constructed simultaneously. Due to nucleophilicity to Zn2+ arising from electronegativity, the layer can accelerate the desolvation process of [Zn (H2O)6]2+ and transfer kinetics of Zn2+ ions, leading to uniform nucleation and effective inhibition of water‐induced side reactions. Meanwhile, the latter is beneficial to guiding Zn (002)‐preferred orientation deposition with compact structure. Consequently, the Zn electrodes with such complementary interface modulation exhibit prominent reversibility. With an area capacity of 1 mAh cm−2 at 1 mA cm−2, the symmetric cell operates steadily for 4000 h. Highly reversible Zn anode is maintained even at 50 mA cm−2. For full cells coupled with MnO2 cathode, impressive rate capability and cycling stability with a high capacity beyond 100 mAh g−1 at 1 A g−1 after 2000 cycles are achieved. The results provide new insights into Zn anodes with high reversibility for next‐generation aqueous zinc ion batteries.
通讯机构：
[Tan, YL ; Yu, F ] H;Hengyang Normal Univ, Coll Phys & Elect Engn, Henghua Rd 16, Hengyang 421002, Hunan, Peoples R China.;Hunan Normal Univ, Minist Educ, Key Lab Low Dimens Quantum Struct & Quantum Contro, Key Lab Matter Microstruct & Funct Hunan Prov, Changsha 410081, Peoples R China.
关键词：
Hydrogen evolution reaction;Metal phosphide;Water splitting;All-pH electrocatalyst;Large-current density
摘要：
The catalytic hydrogen-evolving activities of noble-metal-free catalysts can be greatly enhanced by the crystal structure and components through appropriate interface engi-neering with anion and cation doped into the catalytic materials. However, the de-velopments of inexpensive electrocatalysts suffer from activity incompatibility with different water sources over a wide pH range. Here we report a promising HER electro-catalyst by hybridizing iron phosphide (FeP4) nanoparticles with highly conductive CoP nanowire arrays (abbreviated as FeP4/CoP) through an in-situ two-step phosphorization process, which exhibits outstanding pH-universal hydrogen-evolving activity in different electrolytes with a wide pH range, featured by extremely low overpotentials of 61, 52 and 37 mV to afford a current density of 10 mA cm-2 in neutral, alkaline and acidic electrolytes, respectively. Especially, the as-prepared FeP4/CoP hybrid exhibits extraordinary catalytic performance and long-term stability at large current densities up to 500 mA cm2 for hydrogen evolution in acidic and alkaline electrolytes, indicating its potential substitute for the practical H2 production. This work represents a simple and low-cost strategy toward rational design and development of all-pH catalysts for pH-universal hydrogen evolution.(c) 2023 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.
