Photocatalytic abilities of gel-derived P-doped TiO2

P-doped TiO2 nanoparticles were synthesized through hydrolysis and condensation of Ti(OC2H5)4 with H3PO4 additions. Effects of [H3PO4]/[Ti(OC2H5)4] molar ratios on the anatase-to-rutile phase transformation, crystallite sizes, surface areas, and photocatalytic abilities of the gel-derived P-doped TiO2 were investigated. The P-doped TiO2 nanoparticles prepared by [H3PO4]/[Ti(OC2H5)4]=0.03 were composed of anatase monophase even at 900 oC and possessed very strong photocatalytic ability. Kinetic studies on the P-doped TiO2 to photocatalytically decompose methylene blue under irradiation of 365 nm UV light found that the P-doped TiO2 prepared by [H3PO4]/[Ti(OC2H5)4]=0.03 and calcined at 800 oC had the specific reaction rates, at 25 °C, kA,m=0.76 m3/(kg min) (based on the mass of P-doped TiO2) and kA,BET=46.2×10−6 m/min (based on the BET surface area of P-doped TiO2), which is superior to the performance of a commercial product, P25 (kA,m=0.22 m3/(kg min) and kA,BET=4.8×10−6 m/min).