▎ 摘　　要

A new stable nanocomposite comprising thiol-functionalized lacunary Keggin-type phosphomolybdate (PMo11) and graphene oxide (GO) was prepared via the thiol-ene click reaction. Various characterization techniques, like FT-IR spectroscopy, energy-dispersive X-ray (EDX) spectroscopy, and X-ray diffraction (XRD) analysis showed the strong covalent interaction of GO and PMo11 species and successful formation of PMo11-S-GO nanocomposite. Nitrogen adsorption-desorption analysis revealed the decrease in GO surface area after introducing PMo11 species. The prepared nanocomposite was employed in the electrocatalytic hydrogen evolution reaction (HER) in 0.5 M H2SO4 solution. A low overpotential of 335 mV and small Tafel slope of 71 mV.dec(-1) were obtained in electrocatalytic HER experiments. The nanocomposite exhibited high stability and negligible loss of electrocatalytic activity for at least 850 cycles which is a result of the stable covalent attachment of lacunary Keggin type phosphomolybdate to the surface of GO nanosheets.