Effects of Boron Doping on Photocatalytic Activity and Microstructure of Titanium Dioxide Nanoparticles

Boron-doped TiO 2 nanoparticles were prepared by the sol−gel method and characterized by XRD, TEM, XPS, FT-IR, and UV−vis spectroscopy. XRD results showed that the doping of boron ions could efficiently inhibit the grain growth and facilitate the anatase-to-rutile transformation prior to the formation of diboron trioxide phase. FT-IR and XPS results revealed that the doped boron was present as the form of B 3+ in B-doped TiO 2 samples, forming a possible chemical environment like Ti−O−B. The lattice parameters at different boron contents and calcination temperatures indicated that B 3+ was likely to weave into the interstitial TiO 2 structure. The photocatalytic activity of the B-doped TiO 2 nanoparticles was evaluated by the photoregeneration of reduced nicotinamide adenine dinucleotide (NADH). All B-doped TiO 2 nanoparticles calcined at 500 °C showed higher photocatalytic activity than pure TiO 2 sample in the photocatalytic reaction of NADH regeneration under UV light irradiation. When the molar ratio of B to Ti was 5%, the TiO 2 nanoparticles could photocatalytically reproduce 94% NADH.