Mo-CeO2 photocatalysts on MICROSCAFS®: Defect and support engineering for enhanced CO2 photoconversion

The development of efficient photocatalysts for CO 2 reduction is crucial for the development of carbon-neutral energy systems and sustainable production of fuels. In this study, Mo-modified CeO 2 nanoparticles were synthesized and immobilized on SiO 2 -TiO 2 porous microspheres (MICROSCAFS®) to improve charge separation, light harvesting, and surface reactivity. Structural and physico-chemical characterization confirmed the successful incorporation of Mo species into the CeO 2 lattice, leading to enhanced oxygen vacancy formation and improved redox properties. The photocatalysts were evaluated for CO 2 photoreduction, where Mo-CeO 2 demonstrated the highest CO and CH 4 production rates, which can be attributed to modifications in the defect and electronic structure of CeO 2 upon Mo doping, enhancing CO 2 adsorption and activation of CO 2 molecules. The Mo-CeO 2 @MICROSCAFS® composite further enhanced generation and selectivity towards H 2 owing to its macroporous architecture and higher surface hydroxyl density, which improved water activation. These findings highlight the synergistic interplay of Mo doping and MICROSCAFS® structuring, establishing Mo-CeO 2 -based materials as promising candidates for sustainable CO 2 photoconversion into value-added fuels.