Enhanced Photocatalytic Coupling of Benzylamine to N-Benzylidene Benzylamine over the Organic–Inorganic Composites F70-TiO 2 Based on Fullerenes Derivatives and TiO 2.

The organic–inorganic composites F70-TiO₂, based on fullerene with carboxyl group derivatives and TiO₂ semiconductor, have been designed and constructed to become an optical-functional photocatalyst via the facile sol–gel method. The composite photocatalyst obtained shows excellent photocatalytic activity for the high-efficiency conversion of benzylamine (BA) to N-benzylidene benzylamine (NBBA) with air pressure at a normal temperature under visible light irradiation. By optimizing the composition, the composites with the 1:15 mass ratio of F70 and TiO₂, denoted as F70-TiO₂(1:15), demonstrated the highest reaction efficiency for benzylamine (>98% conversion) to N-benzylidene benzylamine (>93% selectivity) in this study. However, pure TiO₂ and fullerene derivatives (F70) exhibit decreased conversion (56.3% and 89.7%, respectively) and selectivity (83.8% and 86.0%, respectively). The UV–vis diffuse reflectance spectra (DRS) and Mott–Schottky experiment's results indicate that the introduction of fullerene derivatives into anatase TiO₂ would greatly broaden the visible light response range and adjust the energy band positions of the composites, enhancing the sunlight utilization and promoting the photogenerated charge (e⁻-h⁺) separation and transfer. Specifically, a series of results on the in situ EPR tests and the photo-electrophysical experiment indicate that the separated charges from the hybrid could effectively activate benzylamine and O₂ to accelerate the formation of active intermediates, and then couple with free BA molecules to form the desired production of N-BBA. The effective combination, on a molecular scale, between fullerene and titanium dioxide has provided a profound understanding of the photocatalysis mechanism. This work elaborates and makes clear the relationship between the structure and the performance of functional photocatalysts. [ABSTRACT FROM AUTHOR]