Fabrication of Gd-La codoped TiO2 composite via a liquid phase plasma method and its application as visible-light photocatalysts

Abstract

TiO2 was doped simultaneously with Gd and La using a liquid phase plasma (LPP) reaction to produce a photocatalyst with excellent photoactivity in the visible light region. Gadolinium chloride hexahydrate and lanthanum chloride heptahydrate precursors were used to dope the TiO2 powder with polycrystalline Gd2O3 and La2O3 particles. The doping of TiO2 with rare earth elements using LPP reaction decreased the band gap; the band gap of Gd-La codoped TiO2 photocatalysts (GLTP) was the lowest. The photodegradation efficiency of the TiO2 photocatalysts doped with either Gd or La was superior that of bare TiO2 but the photodegradation efficiency of GLTP was highest in both ultraviolet and visible light sources. Acetaminophen (Acetyl-para-aminophen, APAP) was ultimately decomposed to CO2 and H2O via intermediates, such as p-nitrophenol, hydroquinone and hydroxylhydroquinone, by hydroxyl radicals (HO) formed on the surface of GLTP.