Catechol-Formaldehyde Resin Coated CdS Core-Shell Composite as Robust Photocatalyst for Long-Term Sustainable Artificial Photosynthesis of H₂O₂

Abstract

Catechol-formaldehyde resin (CFR) is very attractive for H ₂O ₂ production via the catalytic process. However, the H ₂O ₂ formation is accompanied by the oxidation of catechol groups to  o-benzoquinone groups on CFR, which will cause irreversible damage to CFR and greatly limit its long-term stable catalytic activity. Herein, CdS/CFR composite photocatalyst with a core-shell structure was synthesized by hydrothermal method. The photogenerated electrons of CdS are used as a powerful driving force for the reversible redox conversion between catechol groups and  o-benzoquinone groups on the CFR, which not only achieves the long-term stability of CFR-catalyzed production of H ₂O ₂, but also promotes the separation efficiency of photogenerated e ^- and h ⁺ in CdS, greatly inhibiting their recombination, so as to maintain CdS stability. The H ₂O ₂ yield of CdS/CFR can accumulate to 1.65 mmol·L ^-1 under visible light for 6 h without sacrificial agent, which is about 3.1 and 2 times that of CdS and CFR, respectively, and CdS/CFR can persist for 10 cycles of photocatalysis (60 h). CdS/CFR also improves the yield of photocatalytic H ₂O ₂ by increasing the selectivity of H ₂O ₂ and inhibiting its decomposition. This work offers a novel tactic for expanding the application of CFR in photocatalytic generation of H ₂O ₂.

Keywords

Hydrogen peroxide / Photocatalysis / Catechol-formaldehyde resin / CdS / Core-shell structures / Oxygen reduction reaction / Charge transfer / Heterogeneous catalysis

RIGHTS & PERMISSIONS

2024 SIOC, CAS, Shanghai, & WILEY-VCH GmbH