Immobilized Single Molecular Molybdenum Disulfide on Carbonized Polyacrylonitrile for Hydrogen Evolution Reaction

Abstract

Designing a MoS₂ catalyst having a large number of active sites and high site activity enables the catalytic activity toward the hydrogen evolution reaction to be improved. Herein, we report the synthesis of a low-cost and catalytically active immobilized single molecular molybdenum disulfide on carbonized polyacrylonitrile (MoS₂-cPAN) electrocatalyst. From the extended X-ray absorption fine structure spectra analysis, we found that the as-prepared material has no metal-metal scattering and it resembles MoS₂ with a molecular state. Meanwhile, the size of the molecular MoS₂ has been estimated to be about 1.31 nm by high-angle annular dark-field scanning transmission electron microscopy. A low coordination number and maximum utilization of the single molecular MoS₂ surface enable MoS₂-cPAN to demonstrate electrochemical performance significantly better than that of bulk MoS₂ by two orders of exchange current density ( j_o) and turnover frequency to the hydrogen evolution.