Carbon quantum dots assisted strategy to synthesize Co@NC for boosting photocatalytic hydrogen evolution performance of CdS

[Display omitted] •The CQDs coordinate with Co2+ to synthesize Co@NC via pyrolysis.•The hydrogen production rate of CdS-3 is 21.8 mmol g-1h−1.•The interaction between CdS and Co@NC is crucial in enhanced HER activity. Photocatalytic water splitting accompanied by the hydrogen production as a prospective method has been placed on solving the double issues of the energy crisis and environment pollution. Therefore, the development of stable and efficient hydrogen evolving photocatalysts is pretty important and urgent. Herein, the Co@NC (Co nanoparticles wrapped by nitrogen doped carbon layers) derived from the mixture of carbon quantum dots (CQDs) and Co2+ as the cocatalyst is loaded on the surfaces of the CdS nanorods (NRs) for photocatalytic hydrogen production. The results show a hydrogen evolution activity of 21.8 mmol g-1h−1 for CdS with 3 wt% loading amount of Co@NC (CdS-3) and 29.8 times higher than that of CdS alone. In addition, an apparent quantum efficiency (AQE) of 41.8% at 420 nm over the CdS-3 is obtained. The enhanced photocatalytic performance of the hybrid nanostructure is largely ascribed to the effective electron transfer (ET) between the CdS NRs and Co@NC, which is confirmed by the electrochemical experiments and photoluminescence (PL) spectra. In all, this work supplies a novel strategy to synthesize universal photocatalytic cocatalysts.