High-Performance Photoelectrocatalytic Reduction Of Co2 By The Hydrophilic-Hydrophobic Composite Cu-Sno2/Zif-8

Photoelectrocatalytic reduction CO2 can solve energy shortages and environmental problems. However, the poor solubility and intense competition of the hydrogen evolution reaction (HER) seriously restrict CO2 activation. Here, a hydrophilic-hydrophobic Cu-SnO2/ZIF-8 composite catalyst was constructed by compounding hydrophobic ZIF-8 with hydrophilic Cu-SnO2. Gas-phase CO2 was directly used to improve the activation efficiency of CO2 molecules, and hydrogen evolution was inhibited. Results showed that when the overpotential was as low as -364 mV, the Faraday efficiency of formic acid reached 68.96%. The maximum current density approached 12.8 mA. cm(-2) at -1.4V versus the Ag/AgCl electrode. The ZIF-8 unique structure promoted electron transfer and Cu-SnO2 dispersion to provide additional active sites. The excellent photocatalytic performance of Cu-SnO2/ZIF-8 may be attributed to the special hydrophilic-hydrophobic structure and the small band gap that can absorb much visible light.