Refining d-band center in Ni0.85Se by Mo doping: A strategy for boosting hydrogen generation via coupling electrocatalytic oxidation 5-hydroxymethylfurfural

Abstract Electrochemical oxidation of biomass convert into worthy production is considered to be a prospective alternative to slow kinetic oxygen evolution reaction (OER) in order to facilitate H2 generation. Herein, Mo-doped Ni0.85Se on the Ni foam (denoted as NF@Mo-Ni0.85Se) was prepared as effective bifunctional catalyst to boost H2 production and translate 5-hydroxymethylfurfural (HMF) into 2, 5-furfuran carboxylic acid (FDCA) simultaneously. Operando electrochemical impedance spectroscopy (EIS) and theoretical calculations confirm that the Mo doping could speed the electron transmission within the catalyst and downshift the d-band center of Ni in NF@Ni0.85Se, which is not only conducive to abating H* adsorption energy, but further promotes the hydrogen evolution reaction (HER) and organic hydrogen adsorption process. The as-synthesized electrocatalysts have shown outstanding hydrogen evolution property in acid, neutral, alkaline and seawater. When the NF@Mo-Ni0.85Se||NF@Mo-Ni0.85Se catalyst couple was employed for HER as well as HMF oxidation in basic electrolytes, the potential only required a potential of 1.50 V to obtain the current density of 50 mA cm−2, lower than that of overall water splitting (1.68 V). This present work especially emphasizes the significance of doping transition metals to improve material properties for constructing bifunctional electrocatalysts towards highly efficient energy utilization.