Magnetically recoverable Fe3O4/g-C3N4 composite for photocatalytic production of benzaldehyde under UV-LED radiation

Selective production of aromatic aldehydes is an important challenge in the synthesis of fine chemicals. This study presents a viable strategy for the production of benzaldehyde using a magnetic recoverable photocatalyst. Graphitic carbon nitride was submitted to a thermal post-treatment, for partial exfoliation (g-CN-T) and combined with magnetic nanoparticles of Fe3O4. The composite containing 18 wt.% of Fe3O4 shows a remarkable magnetic response. The efficiency of this composite was evaluated in the selective photocatalytic conversion of benzyl alcohol into benzaldehyde. A good compromise was observed in terms of selectivity for benzaldehyde formation and ability of recovery at the end of the photocatalytic reaction by the application of a magnetic field. Reutilization experiments using this hybrid material revealed a slight decrease of efficiency after the first run only. Moreover, hydrogen was generated during the photocatalytic production of benzaldehyde. Thus, the combination of gCN-T and magnetic nanoparticles provided an impetus to design a photocatalyst with easy and inexpensive features for selective synthesis of organic compounds.