Synthesis Of Urchin-like Mo₂S₃ Catalyzer And Its Efficient Activity For Hydrogen Evolution Reaction

With the rapid development of society and the sharp increase of population,the demand for energy is increasing,and a series of energy and environmental issues have also emerged.On the one hand,the reserves of the traditional fossil energy are limited,it will be exhausted fleetly if there is no restriction on exploitation;on the other hand,with the extensive use of fossil energy,the environmental pollution is becoming more and more serious.Therefore,a clean and renewable new energy is urgently needed to resolve the issues.Hydrogen,a clean and renewable energy carrier with the highest gravimetric energy density,is considered as a suitable candidate for alternative fossil fuels in the future energy supplies.Electrochemical water splitting is a feasible and effective method for hydrogen production.And the key breach of the electrochemical water splitting is to find a affordabl efficient stable electrocatalyst.In the molybdenum chalcogenide family,molybdenum sesquisulfide?Mo₂S₃?is known as a quasi-one-dimensional compound,and has never been studied as an electro-catalyst for the HER.In this work,we introduce a new method to prepare high-purity Mo₂S₃ through a simple solid-state route with the assistance of molten salt,and study the HER performance of Mo₂S₃.Moreover,the HER performance of Mo₂S₃ was further improved by modification.The paper contains as follow:?1?High-purity urchin-like Mo₂S₃ samples were obtained via a NaCl assisted solid state reaction from Mo and S elements.By comparing with the samples synthesized under different condition,we found that the melting environment provided by the molten salt effectively improved the mobility of elements,and significantly reduced the reaction temperature and reaction time by promoting the transformation from 2H-MoS₂ to Mo₂S₃.And by tuning the amount of NaCl,the phase purity and size of the urchin-like Mo₂S₃ were successfully controlled.The growth mechanism of Mo₂S₃ was investigated by quenching the products with cold water at different reaction times.?2?By comparing with 2H-MoS₂ and 1T'-MoS₂,we studied the HER performance of Mo₂S₃.It can be found that the HER performance of the urchin-like Mo₂S₃ and 1T'-MoS₂ is much more better than 2H-MoS₂ by increasing the conductivity and creating new active sites.And the thermal stability of Mo₂S₃ is better than 1T'-MoS₂,which make Mo₂S₃ a wider application prospect on electrochemical water splitting.?3?By etching the surface of Mo₂S₃ crystals with H₂,we prepared vacancy modified urchin-like Mo₂S₃ catalyst.The concentration of vacancy was controled by tuning the time of H₂ treatment,which can successfully reveal the optimum treatment time of the best HER performance.