Ce and Ni Co-doped iron tungstate nanosheets with Ce→W→Ni electronic conjugation for efficient alkaline hydrogen evolution

A unique “Ce→W→Ni” electronic conjugation channel is constructed. • Theoretical calculations confirm an optimized electronic structure and the d -band center. • In situ Raman results reveal the formation of the “H-down” configuration. • The as-prepared Ce-Fe(Ni)WO 4 /NF exhibits an outstanding HER activity. Orbital hybridization between metal compounds can modulate the electronic structure and d -band center of catalysts to optimize the adsorption energy barriers of reaction intermediates, consequently efficiently regulating catalytic performance. Herein, a Ce and Ni co-doped iron tungstate nanosheet on nickel foam (Ce-Fe(Ni)WO 4 /NF) is rationally designed as an efficient electrocatalyst for the hydrogen evolution reaction (HER). In situ Raman results reveal that the evolution of interfacial water promotes the formation of the “H-down” configuration to expedite the Volmer process for proton generation at the interface. Theoretical calculations confirm that the Ce/Ni co-doping effectively optimizes the electronic structure and the d -band center. Specifically, a unique “Ce→W→Ni” electronic conjugation channel is constructed to regulate the spin state of Ni, and Ni and Ce act as the dual catalytically active sites for favorable intermediate adsorption (Ce for water/hydroxy adsorption and Ni for hydrogen adsorption), thereby lowering the kinetic barrier of HER. Thus, the as-prepared Ce-Fe(Ni)WO 4 /NF exhibits an outstanding HER activity with a low overpotential of 63 mV at 10 mA cm −2 and stable operation for 120 h at 250 mA cm −2 . Moreover, Ce-Fe(Ni)WO 4 /NF also possesses bifunctional catalytic activity for the urea oxidation reaction (UOR), offering a promising route toward low-energy-consumption hydrogen production. This work provides new insights and a theoretical basis for designing high-performance alkaline HER electrocatalysts via multi-element electronic conjugation. Download: Download high-res image (211KB) Download: Download full-size image