Mesoporous TiO with WO functioning as dopant and light-sensitizer: A highly efficient photocatalyst for degradation of organic compound.

The suitable doping or modification on TiO holds promise for improving charge separation and extending light absorption range. Here, WO modifying reduced band gap mesoporous TiO (WO/RM-TiO) due to WO doping was successfully fabricated by immersing mesoporous TiO nanoparticles in the peroxotungstic acid sol with controllable reaction time (0-1 h). The W ions were first incorporated into the TiO lattice to form WOTi bonds, resulting in the formation of WO doping TiO. Then, WO nanoparticles gradually formed and attached on the TiO surface, constructing a novel heterojunction catalyst with WO serving as both dopant and light-sensitizer for TiO. Photocatalytic activity of the resulting WO/RM-TiO depends on the immersing duration in the peroxotungstic acid. The BET analysis shows that 0.5 h-WO/RM-TiO has the largest pore volume of 0.491 cm g and the highest surface area of 82.3 m g, whereas these values decline with prolonged immersing duration. As expected, the optimal efficiency in removing p-nitrophenol (PNP) is achieved over 0.5 h-WO/RM-TiO under visible light irradiation, which is 2.33 times that of the unmodified M-TiO. This should be attributed to the suitable WO doping and WO modification.