Bifunctional TiO2/COF S-scheme photocatalyst with enhanced H2O2 production and furoic acid synthesis mechanism

Coupling photocatalytic H 2 O 2 evolution with simultaneous furfuryl alcohol oxidation can avoid the slow water oxidation reaction and fully utilize photogenerated carriers to produce valuable chemicals. Herein, a COF (denoted as BTTA) was synthesized by the Schiff-base condensation and in-situ grown on the surface of TiO 2 nanofibers. The resultant TiO 2 /BTTA composite has a large interface and a short carrier migration distance. Furthermore, the porous and ultrathin BTTA layers endow the composites abundant active sites and excellent light absorption ability. Remarkably, a H 2 O 2 -evolution rate of 740 μmol L −1 h −1 and a furoic alcohol conversion of 96 % are achieved. In-situ irradiated X-ray photoelectron spectroscopy and electron spin resonance confirm the S-scheme carrier transfer mechanism, which spatially separates photogenerated carriers with strong redox power. This work opens a new door to the rational design of S-scheme photocatalysts for economic and green photosynthesis of H 2 O 2 and organic compounds.