无定型钼硫化物/还原氧化石墨烯的辐射合成及其电催化析氢性能

钼硫化物被认为是一种高效的电催化析氢反应的催化剂,因此其合成方法受到了广泛的研究和关注。本文以四硫代钼酸铵和氧化石墨为前驱体,利用γ射线对其辐照还原,一步法制备了钼硫化物/还原氧化石墨烯(Mo S_x/RGO)复合材料。通过X射线光电子能谱、X射线衍射、透射电子显微镜、Raman光谱等表征手段确认复合材料中的Mo Sx为无定型结构,且氧化石墨烯得到了有效的还原。同时系统研究了吸收剂量、前驱体配比对复合材料作为析氢反应催化剂性能的影响。结果发现,Mo Sx/RGO复合材料具有优异的催化性能,其催化起始电压为110 m V,在电流密度为10 m A·cm~(-2)时过电势仅为160 m V,Tafel斜率为46 m V·dec~(-1),说明该催化剂催化析氢机理为Volmer-Heyrovesy机理。此外,Mo Sx/RGO复合材料还具有良好的催化稳定性。

Radiation Induced Synthesis of Amorphous Molybdenum Sulfide/Reduced Graphene Oxide Nanocomposites for Efficient Hydrogen Evolution Reaction

Molybdenum sulfide is an efficient catalyst for the hydrogen evolution reaction (HER) and its synthesis has attracted significant attention in recent years. In this work, molybdenum sulfide/reduced graphite oxide (MoS_x/RGO) was prepared by the γ-ray induced reduction of ammonium tetrathiomolybdate and graphite oxide. The composition, morphology, and structure of the MoS_x/RGO composites were determined by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), transmission electron microscopy (TEM), and Raman spectroscopy. The results confirmed the formation of amorphous MoS_x/RGO composites. Subsequently, the effects of the absorbed dose and precursor ratio on the performance of the composite material as the catalyst for HER were studied systematically. The resultant MoS_x/RGO composites were found to show excellent catalytic activity towards HER. With a catalyst loading of 0.275 mg·cm^-2, an onset overpotential of 110 mV, a Tafel slope of 46 mV·dec^-1, and a current density of 10 mA·cm^-2 at the overpotential of 160 mV can be achieved. These results can be considered as the proof of Volmer-Heyrovesy mechanism. In addition, the MoS_x/RGO catalyst also showed an excellent long-time stability during the evaluation for HER.