0D/2D CuFe2O4/MXene Z-scheme heterojunction for improved photocatalytic selective oxidation reaction

Abstract

The high rate of recombination of photoinduced electrons and holes restricts their utilization in photocatalysis. In this study, an in-situ synthesis route for the fabrication of 0D/2D CuFe2O4/MXene heterojunctions was proposed. The developed heterojunction enhances the charge transfer during the photocatalytic reaction, and the enhanced mechanism is investigated based on the energy band structures of the heterojunction. The conduction band energies of CuFe2O4 and the MXene are 0.17 and − 0.04 eV, respectively, (vs NHE, pH = 7). Moreover, the valence band energies of CuFe2O4 and the MXene are 2.83 and 1.53 eV, respectively, (vs NHE, pH = 7). Therefore, the Z-scheme mechanism of the heterojunctions is proposed, clarifying how the charge separation efficiency of the material is improved through the transfer of the photoinduced holes from the MXene to CuFe2O4. The heterojunctions exhibit superior activity in the photocatalytic selective oxidation of benzyl alcohol to benzaldehyde showing a yield of 99 %, which is significantly higher than that of pure CuFe2O4 and MXene. The results indicate that the novel 0D/2D heterojunction significantly enhances the selective photocatalytic oxidation of benzyl alcohol, and also indicate that ·O2His themainactive species in the photocatalytic oxidation reaction.