Facile and green synthesis of copper nanoparticles loaded on the amorphous carbon nitride for the oxidation of cyclohexane

Abstract In this work, copper metallic nanoparticles were successfully immobilized on the surface of the amorphous carbon nitride using the pulse laser ablation in liquid (PLAL) technique in different times of laser irradiation (denoted as Cu-time/a-C3N4). This novel amorphous carbon nitride was fabricated by the in-situ one-step pyrolysis of melamine and pluronic P-123 precursors. The as-synthesized Cu-time/a-C3N4 catalysts, as compared with the bulk Cu-time/g-C3N4, demonstrated remarkable surface structures and catalytic activities. The synthesized catalysts were tested in terms of the oxidation reaction of cyclohexane under two different conditions. The optimized catalyst (Cu-20 min/a-C3N4) showed 25.5% conversion of cyclohexane with 52.0% selectivity to adipic acid in the one-pot aerobic oxidation. Further, the Cu-40 min/a-C3N4 catalyst showed a significant photocatalytic activity in the presence of visible light irradiation for the oxidation of cyclohexane to the ketone-alcohol mixture (KA oil), such that there were 88% conversion and 95% selectivity to the KA oil mixture. In both cases, the nanocatalysts showed the reusability of four times without any loss of catalytic activity.