Selenium-induced electronic modulation of indium MOFs for enhanced HER and OER performance

초록

The development of efficient and robust electrocatalysts for alkaline water electrolysis is a key goal towards green hydrogen production. In this study, Se-doped indium MOFs with controllable Se contents (5 wt % and 10 wt %) have been prepared using a facile hydrothermal process and assessed as component electrocatalysts for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Se doping within the In-MOF structure was found to influence the electronic behavior of In (III) coordination sites, as well as to favor adsorption energies of intermediates and charge transfer kinetics. Out of all investigated samples, 5% Se-In-MOF has shown optimal activity and provides overpotentials of 167 mV and 290 mV for HER and OER, respectively, at a current density of 10 mA cm-2 with Tafel slopes of 121 mV dec-1 and 113 mV dec-1, which compare to those of commercial Pt/C and IrO2 catalysts. Electrochemical impedance spectroscopy and ECSA measurements indicated that 5% Se-In-MOF possessed the minimum charge transfer resistance and maximum active sites, which is useful for many future applications.

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