CdS decorated resorcinol–formaldehyde spheres as an inorganic/organic S-scheme photocatalyst for enhanced H2O2 production

Photocatalytic H2O2 production provides a clean and sustainable strategy for artificial photosynthesis. Herein, an inorganic/organic composite photocatalyst was fabricated by in-situ growth of CdS nanoparticles on the surface of resorcinol–formaldehyde (RF) resin spheres. RF spheres played multiple roles: (i) acting as a substrate for the growth of CdS and constructing a core-shell structure with seamless contact; (ⅱ) improving visible light absorption of CdS; (ⅲ) forming an S-scheme heterojunction with CdS and promoting the charge separation and transfer. Consequently, under visible light illumination, CdS/RF composite presented remarkably enhanced H2O2 production activity. Its H2O2 yield in 60 min was 801 μmol L–1, which was 5.2 and 1.5 times higher than that of RF spheres and CdS hollow spheres, respectively. The charge migration between CdS and RF followed the S-scheme photocatalytic mechanism, which was verified by work function measurement, ex-situ and in-situ irradiated X-ray photoelectron spectroscopy. This work brings a novel insight into designing RF-based inorganic/organic S-scheme heterojunction photocatalysts for efficient H2O2 production.