Interfacial charge transfer induced dual- active-sites of RuO2-NiO/NF electrode for high efficiency electrocatalytic hydrogen evolution

Renewable energy plays a crucial role in sustainable development amidst the global energy crisis. Hydrogen， owing to its high calorific value and environmental benignity， emerges as a promising energy source for the future. Hydrogen produced through water splitting boasts high purity， zero pollution during production， and recyclability， thereby holding vast potential. Platinum （Pt） stands out as an exceptional catalyst for the hydrogen evolution reaction （HER）. While commercial Pt/C exhibits high alkaline HER performance， its high cost， material instability， and scarcity hinder widespread adoption. Consequently， this study focuses on developing a high-performance， low-cost， and less-noble transition metal electrocatalyst for HER via water splitting. Utilizing the thermal decomposition method， the heterostructural RuO2-NiO/NF electrode can be industrially produced based on heterogeneous interface engineering. Specifically， Ni（OH）2 and RuO2·H2O precursors are applied to a nickel foam （NF） substrate using a binder， followed by heating at 450 ℃ for 3 h in air to facilitate precursor decomposition， thereby successfully preparing RuO2-NiO/NF heterostructure electrocatalysts. The RuO2-NiO/NF electrodes exhibit remarkable catalytic activity and stability in alkaline HER. Characterization， testing， and density functional theory （DFT） calculations reveal that the heterostructural interface formed by the binding of RuO2 and NiO significantly enhances catalyst performance. At the interface， charge transfer results in the creation of dual active sites， enabling selective adsorption of different adsorbates at distinct active sites. This synergistically promotes the fundamental reactions of water splitting， leading to exceptional alkaline HER catalyst performance. Under a current density of 10 mA·cm-2 in 1 mol·L-1 KOH solution， an overpotential of 52 mV and a Tafel slope of 47.5 mV·dec-1 are achieved. Additionally， the turnover frequency （TOF） at 100 mV reaches 0.342 s-1， and a stable potential is maintained at a current density of 200 mA·cm-2 after 100 h of stability testing. In summary， a heterostructure RuO2-NiO/NF electrocatalyst has been successfully developed based on interface engineering principles， with a comprehensive investigation of its HER catalytic mechanism. This provides a novel perspective for constructing heterostructure catalysts based on Ni compounds and their application in electrocatalysis.