Artificial Photosynthesis over Tubular In2O3/ZnO Heterojunctions Assisted by Efficient CO2 Activation and S-Scheme Charge Separation

Solar-driven CO2 reduction shows promise in alleviating climate change and energy crises, but it suffers from difficult CO2 activation and rapid electron/hole recombination in current photocatalysts. Here we develop novel metal-organic frameworks (MOFs)-derived In2O3/ZnO tubular S-scheme heterojunction photocatalyst for CO2 photoreduction. Resulting from Fermi level difference and electron transfer, an internal electric field is built at heterojunction interfaces and contributes to the formation of S-scheme heterojunctions, as unveiled by in situ irradiation X-ray photoelectron spectroscopy and time-resolved photoluminescence spectroscopy. CO2 molecules are chemisorbed and activated over the photocatalyst in views of DFT simulations. The CO2 photoreduction follows a *COOH-intermediate pathway and affords an enhanced CO production rate (12.6 mu mol g(-1)) with nearly 100% selectivity in the absence of any molecular cocatalyst or scavenger. The enhanced performance is ascribed to the efficient charge separation, stronger redox ability, and powerful CO2 activation of In2O3/ZnO S-scheme heterojunctions.

Automated summary

We developed a novel metal-organic frameworks (MOFs)-derived In2O3/ZnO tubular S-scheme heterojunction photocatalyst for solar-driven CO2 photoreduction. The efficient charge separation, stronger redox ability, and powerful CO2 activation of the In2O3/ZnO S-scheme heterojunctions contribute to the enhanced CO production rate and nearly 100% selectivity.