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

• An in-situ synthesis route is explored to fabricate 0D/2D CuFe 2 O 4 /MXene heterojunction. • The heterojunctions exhibited superior activity for photocatalytic selective oxidation of benzyl alcohol to benzaldehyde with yield of 99%. • The enhanced charge transfer mechanism is elaborated based on the measurement of energy band structures of heterojunction. • Z-scheme mechanism in the heterojunctions is proposed for transfer photoinduced holes from MXene to CuFe 2 O 4 . 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 CuFe 2 O 4 /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 CuFe 2 O 4 and the MXene are 0.17 and −0.04 eV, respectively, ( vs. NHE, pH = 7). Moreover, the valence band energies of CuFe 2 O 4 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 CuFe 2 O 4 . 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 CuFe 2 O 4 and MXene. The results indicate that the novel 0D/2D heterojunction significantly enhances the selective photocatalytic oxidation of benzyl alcohol, and also indicate that ·O 2 H is the main active species in the photocatalytic oxidation reaction.