Facile synthesis and enhanced photocatalytic activity of porous Sn/Nd-codoped TiO2 monoliths

Abstract

Herein, we report a facile route of synthesis that includes sol–gel method followed by the high temperature calcination with the aim to synthesize porous Sn/Nd-codoped TiO2 monoliths with crystallized anatase walls using polystyrene spheres as template. Our results showed that both Sn and Nd dopant were well dispersed in the host matrix of the final product. Moreover, this as-synthesized porous Sn/Nd-codoped TiO2 composite showed relatively narrow band gap compared to the pure anatase phase of TiO2, which may have its origin from the contributions from the Sn4+ and Nd3+ impurities. Interestingly, beside the narrowing of band gap in the codoped TiO2, the doping also have a positive effect to help reduced the charge recombination rate, which can be seen from the enhanced lifetime of photogenerated electrons/hole pairs. Finally, the photocatalytic activity of this interesting porous Sn/Nd-codoped TiO2 monolith was examined by carrying out the dye degradation experiments on methyl orange under UV–vis irradiation. The porous Sn/Nd-codoped TiO2 monolith showed better catalytic activity than the pure TiO2 and Degussa P25 due to its narrow band gap, reduced photoinduced h+/e− pair recombination rate, and relatively large surface area. The synergistic combination of doping and surface area enhancement (porous structure) can be adopted as a promising material design strategy to develop photocatalyst materials for degradation of organic pollutants.