Fe/N co-doped nano-TiO2 wrapped mesoporous carbon spheres for synergetically enhanced adsorption and photocatalysis

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.