Hollow TiO2 spheres with improved visible light photocatalytic activity synergistically enhanced by multi-stimulative: Morphology advantage, carbonate-doping and the induced Ti3 +

Great efforts have been devoted to improve the photocatalytic activity of TiO_2 in the visible light region. Rational design of the external structure and adjustment of intrinsic electronic status by impurity doping are two main effective ways to achieve this purpose. A facile onepot synthetic approach was developed to prepare C-doped hollow TiO_2 spheres, which simultaneously realized these advantages. The synthesized TiO_2 exhibits a mesoporous hollow spherical structure composed of fine nanocrystals, leading to high specific surface area(~180 m~2/g) and versatile porous texture. Carbonate-doping was achieved by a postthermal treatment at a relatively low temperature(200°C), which makes the absorption edge red-shifted to the visible region of the solar spectrum. Concomitantly, Ti~(3+) induced by C-doping also functions in improving the visible-light photocatalytic activity by reducing the band gap. There exists a synergistic effect from multiple stimulatives to enhance the photocatalytic effect of the prepared TiO_2 catalyst. It is not out of expectation that the asprepared C-doped hollow TiO_2 spheres exhibits an improved photocatalytic activity under visible light irradiation in organic pollutant degradation.

Hollow TiO_2 spheres with improved visible light photocatalytic activity synergistically enhanced by multi-stimulative: Morphology advantage,carbonate-doping and the induced Ti~(3+)

Great efforts have been devoted to improve the photocatalytic activity of TiO₂ in the visible light region. Rational design of the external structure and adjustment of intrinsic electronic status by impurity doping are two main effective ways to achieve this purpose. A facile one-pot synthetic approach was developed to prepare C-doped hollow TiO₂ spheres, which simultaneously realized these advantages. The synthesized TiO₂ exhibits a mesoporous hollow spherical structure composed of fine nanocrystals, leading to high specific surface area (~ 180 m²/g) and versatile porous texture. Carbonate-doping was achieved by a post-thermal treatment at a relatively low temperature (200°C), which makes the absorption edge red-shifted to the visible region of the solar spectrum. Concomitantly, Ti^3 + induced by C-doping also functions in improving the visible-light photocatalytic activity by reducing the band gap. There exists a synergistic effect from multiple stimulatives to enhance the photocatalytic effect of the prepared TiO₂ catalyst. It is not out of expectation that the as-prepared C-doped hollow TiO₂ spheres exhibits an improved photocatalytic activity under visible light irradiation in organic pollutant degradation.