Phase stabilities and photocatalytic activities of P/Zn–TiO2 nanoparticles able to operate under UV–vis light irradiation

TiO2 nanoparticles doped with total 5 mol% of phosphorus and zinc elements were synthesized using a sol–gel method. The alcoholic solution of tetraethylorthotitanite was mixed with an aqueous solution of Zn(NO3)2 and/or H3PO4, followed by refluxing at 90 °C for 4 h. After centrifugally filtration and drying, the dried particles were calcined at various temperatures and were then physically and chemically analyzed. The results indicated that by doping both zinc and phosphorus elements into Ti–O framework, the resultant TiO2 can maintain anatase monophase at temperatures as high as 800 °C. The P/Zn–TiO2 nanoparticles prepared, using [H3PO4]/[Zn(NO3)2] ≥ 2, at 600–800 °C can decompose ≥96 mol% of the MB after 30 min of UV irradiation and ≥80 mol% of the MB after 60 min of white light irradiation, which are much better than those of the P25 particles.