CoRu alloy synergistically co-catalyzes effective photocatalytic hydrogen evolution reaction of carbon nitride

Developing an efficient and inexpensive Pt-metal-free co-catalyst is of crucial importance but challenging for photocatalytic hydrogen evolution reaction (HER). Herein, a novel CoRu alloy nanosheet-modified g-C3N4 nanotube (TCN) Schottky junction photocatalyst is designed for the first time for photocatalytic HER. The photocatalytic hydrogen evolution rate of the optimized CoRu/TCN photocatalyst is 1601.32 μmol·g−1·h−1, which is 74 and 23 times higher than that of bulk carbon nitride (BCN) and TCN, respectively. Strikingly, its photocatalytic hydrogen production performance is obviously superior to Pt/TCN (1271.32 μmol·g−1·h−1). The experimental and theoretical results confirm that the superior photocatalytic hydrogen evolution activity of CoRu/TCN is ascribed to the formed an interfacial electric field between CoRu alloy and TCN, which improves the interfacial charge transfer kinetics and accelerates charge separation and transfer. Furthermore, the CoRu alloy has an appropriate hydrogen Gibbs free energy (ΔGH*) relative to Pt and Ru metals, uncovering that the synergistic effect of Co and Ru rationally optimizes the Ru–H binding energy. This makes CoRu alloy exhibit superior co-catalytic performance than Pt. This work highlights that the synergistic effect of CoRu alloy markedly strengthens the photocatalytic hydrogen evolution performance and provides new insights for designing efficient Pt alternative hydrogen production co-catalysts.