Medium-entropy CdCoNiS cocatalysts endowed ZnIn2S4 matrix with dual-active sites and charge-transfer “bridge” triggered excellent H2-releasing activity

Utilization of active site and chemical bonding “bridge” to promote the charge transfer and expedite the catalytic kinetics has been regarded as a promising strategy to achieve highly-efficient photocatalysts. Herein, medium-entropy CdCoNiS cocatalysts coupled with ZnIn 2 S 4 matrix were prepared by a solvothermal method and subsequent water-bath treatment. The experimental results and theoretical calculation confirmed that the hydrogen adsorption capacity, charge-transfer dynamics and surface charge utilization were significantly improved due to the successful construction of dual-active sites and chemical bonding “bridge”. As a result, the optimum samples exhibited a high hydrogen evolution rate of 11.4 mmol g −1  h −1 and an apparent quantum efficiency of 11.7% at 420 nm. Moreover, the photostability was evidenced by remaining excellent photoactivity after four cycles. This work may be extended to other medium-entropy cocatalysts and provide an insight for the exploration of efficient photocatalytic hydrogen production system.