Carbonaceous supports decorated with Pt–TiO2 nanoparticles using electrostatic self-assembly method as a highly visible-light active photocatalyst for CO2 photoreduction

Supported Pt–TiO₂ photocatalysts on carbonaceous supports were synthesized by the electrostatic self-assembly method to study CO₂ photoreduction to produce CH₄. Catalytic activities of the prepared photocatalysts were correlated with the particle size and dispersion of the active metal, which in turn depended on the type of carbonaceous support used, varying in the order of multi-walled carbon nanotubes (MWCNT) > Single-walled carbon nanotubes (SWCNT) > reduced graphene oxide > activated carbon. Generally, all catalysts were highly photoresistant with less than 5% loss of activity in terms of CH₄ yield. Pt–TiO₂/multi-walled carbon nanotubes exhibited better catalytic activity compared with other samples and resulted in the highest yield of CH₄ (1.9 μmol gCat−1 h−1).