Enhanced electrochemical performance and photocatalytic activity of mixed-phase anatase/rutile TiO2 @ SiO2 core-shell nanoparticles

This work provides a comprehensive investigation of the electrochemical and photocatalytic activity of anatase/rutile mixed-phase TiO₂@SiO₂ core-shell nanoparticles. From X-ray diffraction analysis, the tuned weight percentage of the anatase and rutile phases for varying calcination temperatures was determined. The different chemical bonds and active energy modes of the dual phase were studied using the FTIR and Raman analysis. The mixed-phase compositions exhibited a gradual redshift in absorbance strength as observed from the UV-Visible spectroscopy. The spherical morphology, lower particle size, and the core-shell formation were confirmed using TEM analysis. The XPS analysis detected the prevalent presence of Ti⁴⁺, Si⁴⁺ elements. The highest BET surface area measurements (522 m²/g) of TiO₂@SiO₂ core-shell nanoparticles enhanced the photoactivity to achieve 95% efficiency in degrading Congo red dye. Also, the mixed-phase TiO₂@SiO₂ nanoparticles have shown a remarkable specific capacitance of 471.8 F/g^-1 at the current density of 1 A/g^-1 for 5000 cycles with 94% capacitance retention.