Enhancing the photocatalytic activity of defective titania for carbon dioxide photoreduction via surface functionalization. Issue 2 (8th December 2021)

• Record Type: Journal Article
• Authors: Zhang, Lina; Zhao, Qianyu; Shen, Lu; Li, Qiuye; Liu, Taifeng; Hou, Lili; Yang, Jianjun
• Is Part Of: Catalysis science & technology. Volume 12:Issue 2(2022)
• Page Start: 509
• Page End: 518
• Publication Date: 2021-12-08
• Subjects: Catalysis -- Periodicals; 541.395
• DOI: 10.1039/d1cy01606g
• Languages: English
• ISSNs: 2044-4753

Abstract

Abstract : The hydrophilic surface of defective titanium dioxide lowers its adsorption capacity towards CO2 molecules. Abstract : The hydrophilic surface of defective titanium dioxide lowers its adsorption capacity towards CO2 molecules. To get rid of this drawback, we conducted surface functionalization of defective titania with ammonium fluoride in order to acquire hydrophobicity and increase the adsorption capacity for CO2 molecules. Besides, the surface Ti–F bonds and substitution of excess bulk oxygen vacancies with F ions formed upon the fluorination treatment of defective TiO2 jointly function to promote the separation of photoinduced carriers, and the Ti 3+ –F species formed upon surface functionalization from the surface fluoride and bulk Ti 3+ can form a self-built electric field to allow the Ti 3+ impurity energy level to move upward and improve the reduction ability of photogenerated electrons. Compared with unmodified defective TiO2, the generation rates of CH4 and CO of the optimized F-TiO2 -SBO-3 increased more than 6 and 2 times, respectively. Moreover, corresponding DFT calculations give evidence of the improvement in the photocatalytic activity of fluorinated defective TiO2 photocatalysts; and relevant in situ DRIFTS data provide insights into the increased selectivity of the fluorinated defective titania for CH4 production upon CO2 photoreduction. This approach could be helpful for better understanding the mechanism of the CO2 photocatalytic reaction and for establishing a feasible pathway to acquire highly efficient photocatalysts for CO2 photoreduction.