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 mu mol g(Cat)(-1) h(-1)). (c) 2019 Elsevier Ltd. All rights reserved.