Preparation Of Mo-based Materials For Hydrogen Evolution Reaction

The renewable and sustainable energy carrier of hydrogen(H2)has attracted extensive attention for decades as a promising alternative to fossil fuels because of the highest mass energy density,rich abundance and zero-emission.Electrolysis of water is a most promising method of hydrogen production with advantages of high efficiency and clean environment.Water splitting is however,an uphill process with the energy required to split is 237 kJ/mol.Therefore,it is necessary to have a large overpotential overpotential in the process of hydrogen production,which leads to excessive energy consumption.With the aid of suitable catalysts,it is found that the energy of the water splitting can be reduced and the yield of hydrogen can be improved.Currently,Platinum(Pt)-based noble metals are known as the best HER catalysts,but the high cost and scarcity of noble metals on earth have hindered their further commercial development and large-scale applications.Hence,it is urgent to develop efficient,durable and earth-abundant HER electrocatalysts instead of the rare and precious Pt-group metals.In this paper,we synthesize the Mo-based materials by in situ method on Mo foil as electrocatalysts for HER.The Mo foil not only can expose more the active sites,but also enhance the elect:ronic conductivity,and thereby optimize the HER activity.The main content of the article is as follows:(1)A simple approach for the synthesis of oxygen vacancy rich molybdenum oxide(MoOx)on Mo foil using simple anodization method has been developed.MoO,/Mo electrode exhibits high active for hydrogen evolution reaction(HER)in alkaline solution.The HER performance of MoOx/Mo can be further improved by electrodepositing of small amount of Pt nanoparticles on MoOx.Pt-MoOx/Mo electrode shows high HER performance,which is close to the performance of Pt.(2)We prepared MoSe2/MoO2/Mo hybrids based on the substrate of MoO2/Mo by CVD method.By introducing a layer of MoO2 on Mo foil,MoSe2/MoO2 hybrid nanosheets with an abundant edge and high electrical conductivity could be synthesized on the surface of Mo foil.Metallic MoO2 can improve the charge transport efficiency of MoSe2/MoO2,thereby enhancing the overall HER performance.(3)We obtained MoS2(1-x)Px/MoO2 hybrids by doping of MoS2 with P element.The results of analyzation and characterization indicate that the MoS2(1-x)Px/MoO2 hybrids could maximally expose active edge sites by the doping of P element,and improving the HER activity.