水热法合成MoS_(2)/RGO的复合物及其电催化析氢性能研究

Hydrothermal Synthesis of Molybdenum Disulfide/Graphene Composites and Their Electrocatalytic Proporties for Hydrogen Evolution

以石墨烯、钼酸铵和硫脲为原料,通过控制质量配比,采用水热法合成了具有不同质量比的二硫化钼/还原氧化石墨烯(MoS_(2)/RGO)复合材料.采用X射线衍射、拉曼光谱、扫描电子显微镜以及透射电子显微镜对该复合材料的结构和形貌进行了表征,结果发现MoS_(2)/RGO质量比为1∶2时,形成的层间化合物分散良好,且MoS_(2)锚定在RGO表面,形成异质结构.通过电化学测试对MoS_(2)/RGO电催化析氢性能进行了研究,发现HER过程可能是由Volmer-Heyrovsky机制发生的,先是快速放电过程,然后是电化学脱附过程.原料MoS_(2)/RGO质量比为1∶2时,具有较小的Tafel斜率(32 mV/dec)、较低的过电位(145 mV)和良好的化学稳定性.

Molybdenum disulfide/reduced graphene oxide(MoS_(2)/RGO)composites with different mass ratios were synthesized by hydrothermal method with reduced graphene oxide,ammonium molybdate and thiourea as raw materials.The structure and morphology of the composites were characterized by X-ray diffraction(XRD),Raman spectroscopy(Raman),scanning electron microscopy(SEM)and transmission electron microscopy(TEM).The results showed that when the mass ratio of MoS_(2)/RGO was 1∶2,the interlayer compound formed was well dispersed,and MoS_(2)was anchored on the surface of RGO to form a heterostructure.The electrocatalytic hydrogen evolution performance of MoS_(2)/RGO was studied by electrochemical test.It was found that the HER process may be caused by the Volmer-Heyrovsky mechanism,which is first a rapid discharge process and then by the electrochemical desorption process.The electrochemical test results show that MoS_(2)/RGO has a smaller Tafel slope(32 mV/dec),lower overpotential(η_(10)=145 mV/dec)and good chemical stability,when the mass ratio of MoS_(2)/RGO is 1∶2.