Carbonaceous Structures as Electronic Bridges to Enhance Charge Migration and Radical Reactions in Composite Photocatalysts: An Effective Way to Achieve Efficient Mineralization of Pollutants

ABSTRACT The intrinsic correlation between photo-induced extraction of hole and free radical reactions can facilitate the mineralization of contaminants via promoting the transfer of electrons from the semiconductor to the solution. TiO 2 /C/g-C 3 N 4 composite photocatalysts are prepared using thermal polycondensation and sol-gel methods in this paper. The introduction of carbon at the interface between the two phases creates charge migration channels that facilitate electron transfer at the interface of semiconductor catalyst as well as collisions of dissolved oxygen to the catalytic sites, which are able to promote catalytic oxidation reactions. Considering Rh-B as target, the removal rate is 97.2±0.2% within 90   min. The involvement of hydroxyl radicals and superoxide radicals is confirmed by carrying out radical quenching experiments and ESR characterization, suggesting that effective electron transfer synergistically promotes the production of hydroxyl radicals. Therefore, it emphasizes the importance of the indeterminate carbon bridged 2D/3D interface for constructing charge migration channels as well as promoting the efficiency of carrier separation in the process of photocatalytic efficient degradation of dyes.