In-situ preparation of TiO2/N-doped graphene hollow sphere photocatalyst with enhanced photocatalytic CO2 reduction performance

Photocatalytic CO2 conversion efficiency is hampered by the rapid recombination of photogenerated charge carriers. It is effective to suppress the recombination by constructing cocatalysts on photo-catalysts with high-quality interfacial contact. Herein, we develop a novel strategy to in-situ grow ultrathin N-doped graphene (NG) layer on TiO2 hollow spheres (HS) with large area and intimate interfacial contact via a chemical vapor deposition (CVD). The optimized TiO2/NG HS nanocomposite achieves total CO2 conversion rates (the sum yield of CO, CH3OH and CH4) of 18.11 mu mol g(-1) h(-1), which is about 4.6 times higher than blank TiO2 HS. Experimental results demonstrate that intimate interfacial contact and abundant pyridinic N sites can effectively facilitate photogenerated charge carrier separation and transport, realizing enhanced photocatalytic CO2 reduction performance. In addition, this work provides an effective strategy for in-situ construction of graphene-based photo-catalysts for highly efficient photocatalytic CO2 conversion. (C) 2021, Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

Automated summary

In-situ growth of ultrathin N-doped graphene on TiO2 hollow spheres can enhance photocatalytic CO2 conversion efficiency. The optimized nanocomposite significantly increases CO2 conversion rates. Experimental results demonstrate that intimate interfacial contact and specific nitrogen sites contribute to improved separation and transport of photogenerated charge carriers.