B/Co/Fe tridoped TiO2/SiO2 composite films for improved photocatalytic degradation of organic pollutants under visible light

• Published in: Inorganic chemistry communications Vol. 119; p. 108089
• Main Authors: Cheng, Jia-nan, Zhao, Li-zhu, Li, Guo-bao, Li, Fang, Yao, Ming-ming
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.09.2020
• Subjects: B/Co/Fe tridoped; Photodegradation; Synergistic effects; TiO2/SiO2 composite; Photodegradation; Synergistic effects; B/Co/Fe tridoped; TiO2/SiO2 composite
• ISSN: 1387-7003; 1879-0259
• DOI: 10.1016/j.inoche.2020.108089

Photocatalytic mechanism schematic of B/Co/Fe tridoped TiO2/SiO2 composite films. [Display omitted] •We successfully synthesize the B/Co/Fe tridoped TiO2/SiO2 composite films.•The films exhibit effective photodegradation of organic contaminants under visible light irradiation.•The synergistic effects of SiO2 compositing and B/Co/Fe tridoping overcome the inherent defects of TiO2. In order to effectively overcome the inherent defects of TiO2 in practical applications including low quantum efficiency and wide band gap, the B/Co/Fe tridoped TiO2/SiO2 composite films with high photocatalytic properties were prepared by the sol-gel method. The physicochemical properties of catalysts were characterized by XRD, FE-SEM, EDS, DTA-TG, BET, DRS and PL. The results shown that the compositing of SiO2 and doping of B/Co/Fe ions in TiO2 could effectively inhibit the phase transformation of anatase to rutile and the growing of crystal grains at high annealing temperatures. The compositing of SiO2 could enhance the specific surface area (82.6 increased to 335.8 m2/g) of samples and provide more adsorption sites. The doping of B/Co/Fe tridoping could form impurity levels in the band gap of TiO2 to shorten the band gap energy (2.54 ev). And the B/Co/Fe tridoped TiO2/SiO2 films could increase the interfacial transfer rate and decrease recombination rate of electrons and holes. The photocatalytic activities of the B/Co/Fe tridoped TiO2/SiO2 films were evaluated under UV or visible light irradiation with two pollutants as target for photodegradation. The results indicated that the films exhibited more excellent photocatalytic activities compared to pure TiO2. The plausible photocatalytic degradation mechanism had been proposed.