Efficient and Stable Electrocatalytic Oxygen Evolution from MoTe x /Ni(OH)2 Heterostructures

초록

A design methodology is presented here for MoTe x /Ni(OH)2 heterostructured catalysts that enhance the oxygen evolution reaction (OER) in water electrolysis. This approach relies on the transfer of mechanically exfoliated MoTe2 nanosheets to Au/Si substrates followed by electrochemical Te dissolution to induce defect-mediated, partial semiconducting (2H) to metallic (1T') phase transitions. Immersing the resulting MoTe x into a nickel nitrate hydrate solution results in a heterostructure consisting of 2H-MoTe x /Ni(OH)2 and 1T'-MoTe x /Ni(OH)2 domains, which enables high stability and improved efficiency for the OER compared to IrO x . Both machine-learning potential and density functional theory calculations searched and evaluated all atomic sites for this materials system, thus revealing the enhancement mechanisms of OER via four-electron transfer processes with lowered free energy barriers in the rate-determining steps.

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