Synthesis of a plasmonic CuNi bimetal modified with carbon quantum dots as a non-semiconductor-driven photocatalyst for effective water splitting

Abstract In artificial photocatalysis, attention is focused mainly on semiconductor photocatalysts, due to their long research history and excellent photocatalytic performance. Here, we demonstrate that dendrite-like plasmonic CuNi bimetal, used as a nonsemiconductor photocatalyst, produces electrons for photocatalytic water splitting by the surface plasmon resonance (SPR) effect of the CuNi bimetal. Carbon quantum dots (CQDs), by virtue of their outstanding charge transfer properties, serve as a co-catalyst that can facilitate the transfer of the photoinduced charge. The photocatalytic water splitting rate of the CuNi bimetal was significantly improved after modification with CQDs, and the highest hydrogen evolution rate was 55.19 μmol g −1 h −1 , with an oxygen evolution rate of 27.51 μmol g −1 h −1 , when the content of CQDs in the photocatalyst was 3 wt%. X-ray diffraction and X-ray photoelectron spectroscopy characterization reveal that the structure and state of the element in the photocatalyst remain unchanged after four consecutive cycles of, cumulatively, 20 h. Our findings may help in the development of a non-semiconductor-driven photocatalytic system for application in the photocatalytic field.