Abstract: Aiming to develop a photocatalyst that can simultaneously produce valuable chemicals and clean H₂ fuel for promoting the utilization efficiency of solar energy, herein, a sea-urchin-like CoP@Ni₂P binary nanojunction was employed as an efficient photothermal cocatalyst to couple with zero-dimensional CdZnS (CZS) solid solution for achieving superior coordinative redox reaction. The CoP@Ni₂P/CZS hybrid displayed a high solar-driven H₂ generation rate of 40.92 mmol g^-1 h^-1 coupling with a benzaldehyde formation rate of 20.33 mmol g^-1 h^-1, which was 16.4 and 8.0 times higher than that of bare CZS. Furthermore, the CoP@Ni₂P/CZS hybrid also achieved a high photothermal H₂ production under a broad light range from 420 to 720 nm, and the H₂ production reached 44.48 µmol g^-1 h^-1 under the 720 nm light illumination. The enhanced catalytic performance can be ascribed to that the CoP@Ni₂P nanojunction with photothermal effect can speed up the separation and transport of carriers, offer more catalytic active sites, and induce an increase in temperature to optimize reaction kinetics. This study may open a facile route to design novel binary metal phosphides with dual functions in photocatalysis for the full exploitation of solar energy.

Key words: H₂ production, Selective oxidation, Photothermal, CoP@Ni₂P cocatalyst, CdZnS solid solution