MoSx supported graphene oxides with different degree of oxidation as efficient electrocatalysts for hydrogen evolution

By Hu, Wen-Hui; Shang, Xiao; Han, Guan-Qun; Dong, Bin; Liu, Yan-Ru; Li, Xiao; Chai, Yong-Ming; Liu, Yun-Qi; Liu, Chen-Guang
Published in Carbon NULL 2016

Abstract

Abstract A simple wet chemical method has been used to prepare MoSx in situ grown on graphene oxide (MoSx/GO) as a highly active and stable electrocatalyst for hydrogen evolution reaction (HER). The role of the oxygen-containing functional group on the surface of {GO} with different oxidation degrees have been studied for obtaining MoSx/GO with excellent electrochemical activity for HER. The electrochemical measurements show that MoSx/GO using the medium degree of oxidation of {GO} as matrix exhibits best electrocatalytic activity for {HER} with a small overpotential of ?195 mV at the current density of 20 mA cm?2. A tafel slope of ?47.7 mV per decade is obtained for MoSx/GO modified electrode. The turnover frequency per active site is calculated. Both the amount of active sites for {HER} and conductivity of the electrocatalyst have been greatly improved owing to the good dispersion and conductivity provided by {GO} matrix. Therefore, this work suggested that choosing {GO} with suitable oxidation degree as support is the key for synthesizing MoSx based electrocatalysts with enhanced {HER} activity.

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