A unique Janus PdZn-Co catalyst for enhanced photocatalytic syngas production from CO2 and H2O

The development of excellent catalyst to achieve photocatalytic syngas production from CO2 and H2O is a prospective and sustainable strategy to alleviate environment and energy crisis. In this study, a unique Janus PdZn-Co catalyst is prepared by annealed the Pd/IRMOF-3(Co, Zn) precursor. Due to the strong interaction, the electron transfers from PdZn terminal to Co terminal in the Janus structure. The electron-received Co terminal facilitates Co sites coordinate with the electrophilic C atom of CO2 and the electron-donated PdZn center is easier to coordinate with nucleophilic O atoms of H2O or CO bonds. The charge redistribution enhances the absorption of CO2 and H2O, which promotes H2 evolution and CO production. In addition, the carbon shell effectively suppresses the metal core agglomeration and facilitates the electron transmission from photosensitizer to metallic active sites. Meanwhile, the ratio of CO/H2 can be regulated (∼3:1 to 2:1) by adjusting the proportion of Co and PdZn. The Janus structure and graphite carbon synergistically play a profound impact on improving the photocatalytic performance. The optimized PdZn-Co catalyst exhibits a superior photocatalytic CO production rate (20.03 µmol/h) and the H2 generation rate (9.90 µmol/h) with a ratio of CO/H2 = 2.02.