Interfacial Engineering of MoO₂‐FeP Heterojunction for Highly Efficient Hydrogen Evolution Coupled with Biomass Electrooxidation

Abstract

Simultaneous highly efficient production of hydrogen and conversion of biomass into value-added products is meaningful but challenging. Herein, a porous nanospindle composed of carbon-encapsulated MoO₂ -FeP heterojunction (MoO₂ -FeP@C) is proposed as a robust bifunctional electrocatalyst for hydrogen evolution reaction (HER) and biomass electrooxidation reaction (BEOR). X-ray photoelectron spectroscopy analysis and theoretical calculations confirm the electron transfer from MoO₂ to FeP at the interfaces, where electron accumulation on FeP favors the optimization of H₂ O and H* absorption energies for HER, whereas hole accumulation on MoO₂ is responsible for improving the BEOR activity. Thanks to its interfacial electronic structure, MoO₂ -FeP@C exhibits excellent HER activity with an overpotential of 103 mV at 10 mA cm^-2 and a Tafel slope of 48 mV dec^-1 . Meanwhile, when 5-hydroxymethylfurfural is chosen as the biomass for BEOR, the conversion is almost 100%, and 2,5-furandicarboxylic acid (FDCA) is obtained with the selectivity of 98.6%. The electrolyzer employing MoO₂ -FeP@C for cathodic H₂ and anodic FDCA production requires only a low voltage of 1.486 V at 10 mA cm^-2 and can be powered by a solar cell (output voltage: 1.45 V). Additionally, other BEORs coupled with HER catalyzed by MoO₂ -FeP@C also have excellent catalytic performance, implying their good versatility.