Triple Regulation of Superhydrophilic-Superaerophobic Mo,V-NiS/NiS Heteronanoflowers for Efficient Bifunctional Water Splitting and Multi-Source Energy-Driven Hydrogen Production.

The urgent demand for sustainable energy has highlighted electrocatalytic water splitting as a key carbon-neutral technology. However, nickel sulfide-based catalysts face challenges of limited intrinsic activity and inefficient gas bubble release. Herein, a triple-engineering strategy constructs a hierarchical Mo, V-co-doped NiS/NiS heteronanoflower electrode in situ on nickel foam (NF) via a one-step hydrothermal synthesis. The synergistic effects of dual-atom doping and phase-separated heterointerfaces not only optimize electronic structure but also confer superhydrophilic and superaerophobic surface properties, significantly enhancing both hydrogen evolution reaction (HER; 55 mV@10 mA cm) and oxygen evolution reaction (OER; 185 mV@10 mA cm) kinetics. The resulting electrocatalyst drives overall water splitting at a low cell voltage of 1.48 V. Density functional theory (DFT) calculations elucidate that Mo/V doping induces strong Ni 3d-Mo/V 3d orbital hybridization, shifting down the d-band center and optimizing the adsorption free energies of H and OOH intermediates. Furthermore, experimental demonstrations confirm the feasibility of water electrolysis driven by mechanical, wind, and solar energies, introducing a novel mechanical-to-hydrogen energy conversion system using triboelectric nanogenerators (TENGs). This work integrates band structure modulation, interfacial engineering, and wettability regulation, advancing the design of bifunctional electrocatalysts for sustainable energy conversion.