Facile mechanochemical modification of g-C3N4 for selective photo-oxidation of benzyl alcohol

Abstract

Graphitic carbon nitride enriched with ZnO or Fe2O3 were synthesized using a simple one-pot mechanochemical method. By using this method, composite samples were synthetized without the production of any potentially hazardous waste. The synthesized materials were used as catalysts during the selective photo-oxidation of benzyl alcohol. Both composite materials displayed an enhancement of the activity and benzaldehyde selectivity with respect to the pure g-C3N4. The most active catalyst was Fe2O3/g-C3N4. The conversion and benzaldehyde selectivity of this sample were 20 and 70 %, respectively. It showed a considerable increase of the benzaldehyde selectivity compared to the pure g-C3N4 and TiO2 P25 commercial reference. A complete structural and electronic characterization using Scanning Electron Microscopy-Energy Dispersive (SEM-EDX), BET measurements, X-ray diffraction (XRD), X-ray Photoelectron (XPS), and UV–visible spectroscopies was carried out. The characterization analysis pointed out the leading role of the crystallinity and surface concentration over the activity and benzaldehyde selectivity of the reaction