Ag and TiO₂ nanoparticles co-modified defective zeolite TS-1 for improved photocatalytic CO₂ reduction

Photocatalytic CO₂ reduction into fuels has been an attractive research topic. Herein, Ag and TiO₂ nanoparticles co-loaded zeolite TS-1 (Ag-TiO₂/TS-1) were synthesized by the ion-exchange and subsequently in-situ photodeposition method. The obtained Ag-TiO₂/TS-1 sample has a high surface area and rich Ti³⁺-V_o defects and as well as highly dispersed Ag nanoparticles. As expected, the sample Ag-TiO₂/TS-1 not only shows high CO₂ adsorption capacity, but also improves the separation efficiency of photogenerated electron-hole pairs. As a result, only CO and CH₄ can be detected on the sample Ag-TiO₂/TS-1 in the photocatalytic CO₂ conversion, and the competing H₂ evolution can be completely suppressed, suggestive of its high selectivity. The super photocatalytic activity toward CO₂ reduction can be ascribed to the synergistic effect among highly dispersed Ag nanoparticle, the support zeolite TS-1 and TiO₂ with highly exposed {101} planes.