| With the development of society,energy has become an important part of people’s lives;while the rapid consumption of fossil energy resulted that the environmental problems became increasingly serious.So,the new sustainable and environmentally friendly energy sources,such as wind,solar,hydrogen and tidal energy,have been continuously explored by scholars in order to solve the above-mentioned environmental problems.In this type of energy system,hydrogen energy has the characteristics of high energy density and greenness.So,its storage and utilization have been extensively studied.The electrocatalytic water splitting technology provides a feasible way for storing electric energy in the chemical bond of H2,which combine the conversion of electric energy and the production of new hydrogen energy.Nevertheless,the production of hydrogen and oxygen energy via water electrolysis is highly dependent on electrocatalysts due to the sluggish kinetics and unfavorable thermodynamics.In this paper,an interesting solid-phase reaction(SPR)method is used to obtain a composite material with heterostructures and abundant defect vacancies at the same time to achieve excellent water splitting catalytic performance.The details are as follows:(1)In this chapter,the RuO2 was loaded on the MoSe2 plane as a precursor firstly.Subsequently,in the heat treatment process under a protective gas atmosphere,the solid-phase reaction occurs and finally forms the RuSe2/MoO2(RSMC)composite structure.In this reaction process,different annealing temperatures affect the composition of the composite material.In the series of annealing temperature,the sample at 500℃(named as RSMC-500)own the best catalytic ability.Then the RSMC500 sample was tested in 1 M alkaline solution,obtained the overpotential value at 10 mA cm-2 during the hydrogen evolution reaction(HER)process was 58 mV;the oxygen evolution reaction(OER)was 270 mV.In addition,when the catalyst RSMC-500 used in overall water splitting as a bifunctional catalyst,it only needs 1.57 V to give a current density of 11 mA cm-2.Then,lots of characterization techniques,such as XRD,XPS EPR and TEM,are used to analyze the RSMC-500 sample.According to these characterization techniques,the well catalytic performance can be attributed to the structure of RSMC-500 not only owns the abundant defects and vacancies,but also forms a compact RuSe2/MoOx interface.(2)Elemental doping is an important choice for modifying the electronic structure of the catalyst surface.It has been proven to improve the conductivity of the catalyst,adjust the energy characteristics of the catalytic intermediate,and develop additional active sites for the catalytic process.Based on the above chapter,P element was successfully doped into sample RSMC-500,for improving the catalytic activity of the material.The different phosphating temperatures and the amount of sodium hypophosphite were adjusted to explore the appropriate temperature and amount of P doping into RSMC-500.It was found that the best catalytic performance was achieved at 400℃ and the mass ratio of RSMC-500 to NaH2PO2 was 1:2.The sample shows excellent electrocatalytic hydrogen evolution(HER)activity in 1 M alkaline electrolyte,the overpotential value(162 mV)at a current of 100 mA cm-2 is much better than commercial Pt/C(215 mV).In addition,it was applied to the ammonia borane hydrolysis system,also obtained well catalytic properties(rB=6492 mlH2 gcata-1 min-1,Ea=29.7 kJ mol-1). |
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