Trace surface fluorination and tungsten-intercalation cooperated dual modification induced photo-activity enhancement of titanium dioxide

• Published in: Journal of industrial and engineering chemistry (Seoul, Korea) 2022, 108(0), , pp.195-202
• Main Authors: Xu, Yifan, Liu, Zhongyuan, Wang, Kunlun, Niu, Chunyao, Yuan, Pengfei, Zheng, Jin You, Kang, Young Soo, Zhang, Xiao Li
• Format: Article
• Language: English
• Subjects: Density functional calculation; Dual modification; Surface fluorination; TiO2; Tungsten doping; 화학공학
• ISSN: 1226-086X; 1876-794X
• DOI: 10.1016/j.jiec.2021.12.035

An environmental benign one-pot dual modification process that utilize soluble sodium tungstate and trace-level sodium fluoride successfully narrowed the bandgap and enabled a localized spatial charges separation which led to rapid charge separation and transfer during photocatalyses. The decoloration efficiency of MB solution was improved by 33.6% and 119.5% under ultraviolet and visible light, respectively, and the photocurrent density reached an enhancement by 181.2%. [Display omitted] •An environmental benign one-pot dual-modification.•Photocurrent density reached an enhancement by 181.2% with enhanced decoloration efficiencies.•Conduction band down-shift and localized spatial charge separation led to fast charge injection. General modification that utilizes insoluble tungstic acid or highly toxic hydrofluoric acid to improve charge separation and transfer in TiO2 results in considerable issues such as uneven doping, significant impacts on particle size and morphology, as well as environmental hazards. In the present work, an environmental benign one-pot dual-modification approach was demonstrated that uses soluble sodium tungstate and only trace-level sodium fluoride as replacements. The photoactivity efficiency for decoloration of methylene blue (MB) solution was improved by 33.6% and 119.5% under ultraviolet and visible light, respectively. Meanwhile, the photocurrent density reached an enhancement by 181.2% by this dual-modification. The dual-modification had negligible influence on the crystal structure and the surface area of the TiO2nanoparticles. Density functional calculation suggested the remarkable improvements of the photocatalysis of TiO2 can be ascribed to the rapid charge separation and transfer owing to the down-shift of conduction band from the tungsten doping and localized spatial charge separation from the surface fluorination enabled by the dual-modification approach.