层状MoS_2/Graphene薄膜的制备及其电催化制氢性能

Preparation of layered MoS_2/ Graphene films and their electrocatalytic performance of hydrogen generation

采用水热合成的方法,以硫脲(NH2CSNH2)为硫源和还原剂,合成出了二硫化钼/石墨烯(Mo S2/Graphene)复合电催化剂用于电解水制氢.将其旋涂到掺杂氟的Sn O2透明导电玻璃(FTO)上制备成Mo S2/Graphene薄膜进行电催化分解水制氢性能测试.研究发现,Mo S2/Graphene的催化活性较纯纳米Mo S2提高了近一倍.这是由于通过化学耦合作用选择性生长在石墨烯上的层状Mo S2其边缘拥有丰富的活性位点,同时石墨烯作为良好的导电基体也能大大加快了电子的转移速度.在0.5 mol/L H2SO4溶液中,Mo S2/Graphene旋涂到FTO上的层数为12层时,其电催化制氢效率最高:起峰电位提前到0.085 V,在0.2 V的过电位下电流密度达到了-4.5 m A/cm2.层状Mo S2/Graphene电催化剂作为Pt族贵金属的替代品,具有广阔的应用前景.

MoS2/ Graphene electrocatalysts which were used for water-electrolytic hydrogen making were synthesized using a hydrothermal method among which NH2CSNH2（ thiourea） was served as both the source of sulfur and the reductive agent. MoS2/ Graphene films prepared on fluorine-doped tin oxide（ FTO） by spin coating method were applied for performance test of electrocatalytic water splitting. The study shows that the activity of MoS2 toward hydrogen evolution reaction improves as high as nearly 100% after coupling with graphene. The high catalytic activity of MoS2/ Graphene was attributed to two aspects： firstly,the selective growth of layered MoS2 on graphene through chemical coupling afforded an abundance of catalytic active sites on MoS2 edges. Secondly,as a good conductive substrate,the graphene sheets can accelerate the electron transfer. The12 layered MoS2/ Graphene catalysts achieved the highest efficiency toward hydrogen evolution reaction with a current density up to-4. 5 m A / cm2 at the overpotential of 0. 2 V and an onset potential of 0. 085 V in0. 5 mol / L H2SO4 solution. Hence,as a substitute for Pt family noble metal toward hydrogen evolution reaction,the layered MoS2/ Graphene has broad application prospects.