层状MoS2/Graphene薄膜的制备及其电催化制氢性能

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.

Preparation of layered MoS2/Graphene films and their electrocatalytic performance of hydrogen generation

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. The 12 layered MoS₂/Graphene catalysts achieved the highest efficiency toward hydrogen evolution reaction with a current density up to -4.5 mA/cm² at the overpotential of 0.2 V and an onset potential of 0.085 V in 0.5 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.