A core–shell TiO2@C nano-architecture: facile synthesis, enhanced visible photocatalytic performance and electrochemical capacitance

In this work, we elegantly devised a bottom-up solvothermal strategy coupled with subsequent controllable calcination to synthesize a core–shell TiO2@C nanohybrid with a uniform ultrathin carbon shell of ∼1–3 nm. Physicochemical investigations revealed that Rutin and ethylene glycol played a great role in successful in situ fabrication of the uniform core–shell nano-architecture. Benefiting from the appealing synergetic effect of the mesoporous core–shell structure and composition advantages, the resulting core–shell TiO2@C with remarkable visible light response exhibited enhanced photocatalytic degradation efficiency and stability for methylene blue under visible light irradiation. Furthermore, the unique core–shell TiO2@C, thanks to its large surface area, rich mesoporosity and high electronic conductivity, demonstrated excellent electrochemical capacitance with a large specific capacitance of 210 F g−1 at 0.2 A g−1, and ∼2% capacitance degradation over cycling for 1200 times in 0.5 M aqueous H2SO4 at a current rate of 1 A g−1.