Decorating Zn0.5Cd0.5S with C,N Co-Doped CoP: An Efficient Dual-Functional Photocatalyst for H2 Evolution and 2,5-Diformylfuran Oxidation

Photocatalytic H2 evolution and biomass-derived alcohol oxidation is a cooperative way for improving the utilization of photogenerated charge carriers. Herein, a highly efficient photocatalyst was fabricated by decorating Zn0.5Cd0.5S with a C,N codoped CoP polyhedron (referred to as CoP, derived from ZIF-67), and then it was used for H2 evolution and 5-hydroxymethylfurfural (HMF) oxidation. For the optimized sample (20% CoP/Zn0.5Cd0.5S), the generated H2 rate is significantly enhanced from that of the HMF aqueous solution with 2,5-diformylfuran (DFF) as a concomitant product, about 31.7 times higher than the pristine Zn0.5Cd0.5S under visible light irradiation. The separation of photoexcited electrons (e–) and holes (h+) in the process was promoted, as both e– and h+ were involved in the desired conversions. From the results of density functional theory (DFT) calculations and in situ XPS spectra, the utilization of e– was further improved as a spontaneous transfer from Zn0.5Cd0.5S to CoP occurred due to the p–n heterojunction formed between Zn0.5Cd0.5S (n type) and CoP (p type). This work provides an efficient method to separate the photoinduced charge carriers and a new way for H2 evolution accompanied by transformation of HMF to DFF.