Improved hydrogen evolution performance of Ni-based nanoporous catalyst with Mo and B co-addition.

The exploration of efficient and stable noble-metal-free electrocatalysts for hydrogen evolution reaction (HER) is of great interest for the development of electrochemical hydrogen production technologies. Herein, nanoporous Ni-based catalyst with Mo and B co-addition (NiMoB) prepared by dealloying is reported as an efficient electrocatalysts for HER. The nanoporous NiMoB achieves an overpotential of 31 mV at 10 mA cm-2, along with exceptional catalytic stability in alkaline electrolyte. Density functional theory (DFT) calculations reveal that the incorporation of Mo and B can synergistically optimize the electronic structure and regulate the adsorption of HER intermediates on the Ni active site, thus accelerating the HER kinetics. This study provides a new perspective for the development of non-precious Ni-based catalysts towards efficient hydrogen energy conversion.

Synthesis and water splitting performance of FeCoNbS bifunctional electrocatalyst.

Transition metal (TM) sulfides are promising catalysts for water splitting in alkaline media due to their high intrinsic activities and similar TM-S electronic structure with hydrogenase. In this work, the nanoporous FeCoNbS electrocatalyst with nanosheet morphology is synthesized through dealloying AlFeCoNb alloy followed by the steam sulphurization. The introduction of S element improves the electronic structure, further increases the active sites, regulates the mass transfer and enhances the intrinsic activity. The Nb introduction improves the electron transfer ability of the catalyst. The synergistic effect of Fe, Co and Nb improves the intrinsic activity of the active site. The FeCoNbS catalyst exhibits good catalytic performance for both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in alkaline solution. The overpotentials at 10 mA cm-2 of HER and OER are 83 and 241 mV, respectively. The Tafel slopes of HER and OER are 101.2 and 35.5 mV dec-1, respectively. The FeCoNbS can serve as overall water splitting electrode with the decomposition voltage of 1.61 V at 10 mA cm-2.