Abstract: Carbon-based adsorption and TiO₂-based photocatalysis are both safe and low-cost ways of pollutant purification. Constructing C-TiO₂ architectures can effectively improve removal efficiency. However, most of those carbon frames only acted as supporting substrates, exhibiting rather limited synergistic action from TiO₂ and carbon. Herein, Fe/N co-doped nano-TiO₂ wrapped on mesoporous carbon spheres with a core-shell structure was designed. The Fe, N co-doped carbon sphere with a hierarchical structure improved the synergy of adsorption and transfer during the photocatalytic process. Without extra dopant, the Fe and N partly exposed on the surface realized the in-situ migrating into the TiO₂ shell to enhance the interface effect, which significantly promoted the photocatalytic efficiency of the composite. Furthermore, the photocatalytic efficiency of the composite was investigated through two typical pollutants under visible-light irradiation. The degradation efficiencies for rhodamine B and paraxylene were 96.2% in 60 min and 94.1% in 20 min, respectively, with the apparent rate constant of 0.045 min^-1 and 0.049 min^-1, 8.3 and 11.4 times of that for bare TiO₂. The composite is likely advantageous for treating diverse environmental pollutants.

Key words: Pollutant, Adsorption-photocatalysis, Porous carbon, Nano-TiO₂, Core-shell structure, Co-doping