| Worldwide,the demand of miniaturized and lightweight energy storage devices is increasing due to the rapid development of new technologies on consume portable,public wearable,implantable electronics and electronic skins in areas such as mobile communications,biometrics,aerospace and defense.With the scarcity of fuel energy,auxiliary electrocatalyst of non-noble metal compound in water decomposition is becoming a potential candidate for cost-effective and high-quality hydrogen production.Supercapacitor and batteries are among the most promising electrochemical energy storage applications at present.Two-dimensional(2D)inorganic nanosheets(NSs)have attracted a lot of research attention because of their unique physicochemical properties in multipurpose building blocks structure,and are used for efficient hybridization electrodes in energy storage technology,acting as hydrogen evolution reaction and oxygen evolution reaction catalysts to improve the efficiency of water decomposition.Hydrogen production,as a very attractive technology for the production of clean energy,has accelerated the development of hydrogen evolution reaction(HER)and oxygen evolution reaction(OER)catalysts towards efficient water decomposition.Adjusting the electronic structure of oxygen evolution reaction and hydrogen evolution reaction electrocatalyst is a promising method to achieve efficient alkaline water decomposition to produce clean(H2)energy.In recent years,the development of advanced hydrogen evolution reaction and oxygen evolution reaction electrocatalysts is of great significance for the development of metal-air cells,fuel cells and electrolytic tanks.The specific research content and innovation results of this paper are as follows:(1)Interface engineering is considered as an effective solution to fabricate efficient composite catalysts for water electrolysis.Two-step electrodeposition method is employed to design hetero-interfaces of Co4S3 nanocrystals on Ni Co layered double hydroxide(Ni Co LDH)nanosheet arrays as electrocatalyst for hydrogen evolution reaction.Constructing interface achieves improved hydrogen evolution catalysis by inducing lattice defects and distortions as active sites,and accelerating charge transfer and kinetics.Co4S3-Ni Co LDH/CC exhibits efficient catalysis performances with overpotential of 124 m V at 10 m A/cm2.(2)Efficient and cheap catalysts that simultaneously catalyze hydrogen evolution and oxygen evolution are urgently desired.Herein,nickel foam supported hybrid Sn S-Ni3S2 is firstly developed via a solvothermal method as advanced dualfunctional catalysts in alkaline media.TEM and electrochemical tests reveal that,the hetero-interface between Sn S and Ni3S2 supplies a large number of defects as catalysis sites for improved activities.In addition,composite catalyst acquires improved charge transfer for catalysis.The sample Sn S-Ni3S2 exhibits good bifunctionality with low overpotentials of 145 m V at 10 m A/cm2 for hydrogen evolution reaction and 298 m V at 20 m A/cm2 for oxygen evolution reaction.For overall water splitting,a low cell voltage of 1.66 V could generate a high current density of 100 m A/cm2 in a two-electrode cell,exhibiting great promise for practical application.(3)Simple low-temperature smallish potential electrochemistry deposition self-assembly technology is used to prepare Cu O nano piece and Ni O nano array on commercial Ni foam(Cu O-Ni O-Ni).Cu O-Ni O-Ni heterogeneity structure has unique layered slice structure,and Ni O provides active surface center of hydroxyl adsorption and effectively accelerates the adsorption of OH-and Volmer steps.The addition of Cu O auxiliary catalyst,which regulates atomic form of Ni O surface through interface engineering greatly improves intrinsic activity.Electron transfer from Cu O to Ni O increases proton affinity of Ni O,and reveals their versatility and practicality in water decomposition.Cu O-Ni O-Ni heterogeneity structure acquires low over-potential calibrated by reversible hydrogen electrode(RHE)in 1 M KOH,when the current density is 10 m A/cm2.The over-potential for hydrogen evolution reaction is 138 m V,and the over-potential for oxygen evolution reaction is 235 m V.For overall water splitting in two-electrode cell,which is driven by the low cell voltage of 1.69 V,can generate current density of 50 m A/cm2.Cu O-Ni O-Ni also... |
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