Enhanced photocatalytic CO2 reduction via the synergistic effect between Ag and activated carbon in TiO2 /AC-Ag ternary composite

Scientific Achievement

 The activated carbon not only leads to enhanced CO₂ adsorption capacity due to its properties and high surface area but also makes the electron transfer to its surface due to similar conductivity to metals derived from diverse electronic structures of activated carbon, thereby suppressing the recombination of photo-generated electron and hole pairs. (2) The oxidation reaction sites of H₂O are located on the surface of TiO₂ and the reduction reaction sites of CO₂ are on the surface of activated carbon; the effective separation of two reaction sites remarkably inhibited the reverse reaction during CO generation. (3) The surface plasmon resonance (SPR) of Ag enables the materials to absorb light in a broader spectrum. 

Significance and Impact

  We assembled TiO₂/AC-Ag ternary composite structure to simultaneously increase CO₂ uptake, extend the light absorption edge, and reduce the recombination of electrons and holes via synergistic effect of AC and metal Ag. This design explored a new approach for the application of biomass carbon and is very valuable for further practical application of photocatalytic CO₂ reduction.

Research Details

  The TiO₂/AC-5-Ag composite photocatalyst was prepared via using ultrasonic and situ photodeposition methods;

  The prepared samples were characterized by SEM, TEM, DSR, BET, PL and so on;

  The CO₂ photo-reduction activities of samples were performed via the photocatalytic system.

Doi.org/10.1016/j.cej.2018.04.180