Bifunctional synergistic CoP/Coral-like g-C3N4 catalyst: Boosting the photocatalytic water splitting hydrogen evolution and appreciation of anisalcohol at same time

Abstract

g-C₃N₄ is an outstanding photocatalytic hydrogen generation material, yet suffers from the low efficiency of carrier separation and high cost of sacrificial agents as well as noble metal cocatalyst. Herein, we report a bifunctional synergistic CoP/coral-like g-C₃N₄ heterojunction (CoP/CorCN), which exhibited superior watersplitting hydrogen evolution activity by replacing a sacrificial reagent with anisalcohol conversion to produce value-added anisaldehyde. Compared with traditional g-C₃N₄, the novel CorCN exhibited increased N_3C vacancies, widened interlayer distance, extended photoresponse range, as well as increased specific surface area. Theoretical calculation results show that the introduced N_3C vacancy enable carbon nitride nanosheets curl into a tube to expose more anisalcohol adsorption sites. Further, the combination of CoP with CorCN dramatically improved the charge transfer kinetics, hence, CoP/CorCN presented an impressive hydrogen evolution rate of 353 μmol∙g⁻¹∙h⁻¹, which is much more higher than that of pristine CorCN, CoP as well as CoP/bulk-CN. In addition, in-situ diffuse infrared spectroscopy, mass spectra and gas chromatography (in-situ FT-IR, MS and GC) were conducted to verify the formation of value-added anisaldehyde and no excessive oxidation products such as acids and CO₂ were produced. These findings present here should be highly useful for promoting the research and development of efficient bifunctional synergistic photocatalyst.