Z-scheme heterostructure of Cu2O/Pt/NH2-MIL-125(Ti) for photocatalytic CO2 reduction

• In this work, the solvothermal method synthesized decahedral Cu 2 O/Pt/NH 2 -MIL-125 (Ti) by adjusting the reaction temperature. • The system characterization (XRD, XPS, SEM, TEM, BET, UV- Vis, EIS, PL) results showed that the synthesized Cu 2 O/Pt/NH 2 -MIL-125 (Ti) had excellent properties such as high quality, stability, and broad absorption band. • In this study, the mechanism of photocatalytic reduction of CO 2 was analyzed in detail. • The study further revealed the significant effect of Z- scheme heterojunction on photocatalytic performance, indicating the great potential of MOFs heterojunction materials for CO 2 reduction applications. Photocatalytic CO 2 and H 2 O synthesis of alcohols is a promising strategy to address the energy shortage and greenhouse effect. However, its wide application is limited by the rapid recombination of charge carriers. A Z-scheme Cu 2 O/Pt/NH 2 -MIL-125(Ti) heterostructure was successfully synthesized in this study. The electrons and holes generated by the photocatalyst can be rapidly separated by the Z-scheme heterostructure. CO 2 and H 2 O are efficiently converted into CH 3 OH and CH 3 CH 2 OH (434.46 and 718.47 µmol g −1 ). Combined with the electrochemical measurements, the efficient inactivation process is attributed to the enhanced light utilization and the effective suppression of photogenerated charge carrier recombination. The electron-hole transfer pathways and reaction mechanisms are proposed through UV-Vis diffuse reflectance spectroscopy, X-ray photoelectron spectroscopy, and radical trapping experiments. In addition, several cycling experiments were also carried out, and the composite catalyst showed excellent stability in water. This Z-scheme heterostructure fabrication can sterically suppress the recombination of photogenerated carriers and expand the absorption range, providing a feasible method for photocatalytic CO 2 synthesis of high-value chemicals. A Z-scheme Cu 2 O/Pt/NH 2 -MIL-125(Ti) heterojunction was successfully synthesized in this study. The electrons and holes generated by the photocatalyst can be rapidly separated by the Z-scheme heterojunction. CO 2 and H 2 O are efficiently converted into CH 3 OH and CH 3 CH 2 OH (434.46 and 718.47 µmol g −1 ). Combined with the electrochemical measurements, the efficient inactivation process is attributed to the enhanced light utilization and the effective suppression of photogenerated charge carrier recombination. The electron-hole transfer pathways and reaction mechanisms are proposed through UV-Vis diffuse reflectance spectroscopy, X-ray photoelectron spectroscopy, and radical trapping experiments. In addition, several cycling experiments were also carried out, and the composite catalyst showed excellent stability in water. This Z-scheme heterojunction fabrication can sterically suppress the recombination of photogenerated carriers and expand the absorption range, providing a feasible method for photocatalytic CO 2 synthesis of high-value chemicals.