A Medium-entropy oxide as a promising cocatalyst to promote photocatalytic hydrogen evolution.

As emerging materials, medium-entropy oxides have attracted wide attention for the huge potential in energy storage, catalytic, magnetic and thermal applications. The electronic effect or the strong synergic effect caused by the construction of medium-entropy system leads to the unique properties of catalysis. In this contribution, we reported a medium-entropy CoNiCu oxide as an efficient cocatalyst for enhanced photocatalytic hydrogen evolution reaction. The target product was synthesized by a process of laser ablation in liquids and graphene oxide was applied as a conductive substrate of it, then it was loaded on the photocatalyst g-CN. The results showed that the modified photocatalysts exhibited the reduced [Formula: see text] and enhanced abilities of photoinduced charges separation and transfer. Furthermore, a maximum hydrogen production rate was measured to be 1177.52 μmol ·g·h under the visible light irradiation, which was about 291 times higher than that of pure g-CN. These findings suggest that the medium-entropy CoNiCu oxide serves as an eminent cocatalyst, which offers a possible pathway towards the broadening of the applications of medium-entropy oxides and provides the alternatives to conventional cocatalysts.