Plasmonic NiN Cocatalyst Boosting Directional Charge Transfer and Separation toward Synergistic Photocatalytic-Photothermal Performance of Hydrogen and Benzaldehyde Production as Well as Bacterial Inactivation.

Charge separation and transfer are the dominating factors in achieving high activity of solar energy-based photocatalysis. Here, a plasmonic transition metal nitride, NiN, nanosheet was fabricated and employed as an efficient cocatalyst to couple with CdZnS (CZS) solid solution via a self-assembly method to form a novel NiN/CZS heterojunction with an intimate interface. On one hand, localized surface plasmon resonance of the NiN nanosheets endowed the fabricated NiN/CZS composite with a wide-spectrum light absorption capacity, even to the near-infrared range. On the other hand, NiN as a cocatalyst can not only effectively induce the directional electron transfer from CZS to NiN active sites but also enhance the surface charge separation efficiency of the NiN/CZS heterojunction by 4.1 times compared to that of pure CZS. Plasmonic NiN also provided a photothermal effect to enhance the surface temperature of the composite for boosting the catalytic reaction kinetics. As a result, under visible light irradiation, the optimal NiN/CZS composite exhibited simultaneous H generation and benzaldehyde formation rates of 35.08 and 16.44 mmol g h, which were 9.4 and 5.9 times those of CZS, respectively; and the composite also demonstrated a strong antibacterial ability with a sterilization rate of 99.7% toward . Besides that, under NIR light, plasmonic NiN offered extra hot electrons that can transfer back to CZS to take part in the photocatalytic reaction, leading to the NiN/CZS composite still having a high H production of 179.6 μmol g h. This work focuses on developing and applying novel plasmonic cocatalysts in photocatalysis for achieving adjustable electron transfer and fast charge separation for extensive practical application.