Effect of Ti (III) Surface Defects on the Process of Photocatalytic Reduction of Hexavalent Chromium. Issue 2 (11th February 2017)

• Record Type: Journal Article
• Authors: Qin, Hongxia; Bian, Yingying; Zhang, Yaxi; Liu, Longfei; Bian, Zhenfeng
• Is Part Of: Chinese journal of chemistry. Volume 35:Issue 2(2017)
• Page Start: 203
• Page End: 208
• Publication Date: 2017-02-11
• Subjects: Ti3+ modification -- titanium dioxide -- photocatalytic reduction -- hexavalent chromium -- surface selective adsorption and desorption; Chemistry -- Periodicals; 540.5
• DOI: 10.1002/cjoc.201600578
• Languages: English
• ISSNs: 1001-604X

Abstract

Abstract: In this paper, the process of photocatalytic reduction of hexavalent chromium was investigated over Ti 3+ ‐modified TiO2 photocatalysts. The Ti 3+ surface defects were repaired by annealing as‐prepared sample at different temperatures to control the amount of Ti 3+ sites. The samples were characterized by SEM, XRD, BET, UV–vis absorption, EPR and XPS. The results showed Ti 3+ defects were successfully doped in TiO2 . The surface selective adsorption of hexavalent chromium [Cr2 O7 2 − (Cr(VI))] and the desorption of trivalent chromium [Cr 3+ (Cr(III))] were investigated during the process of photocatalytic reduction. Zeta potential results presented that the increased positive charges due to more Ti 3+ defects on the surface show a significant improvement for adsorption of Cr(VI). Accordingly, the surface positive charges controlled by the Ti 3+ defects play important roles in the photocatalytic reduction of Cr(VI). Abstract : The adsorption selectivity of Ti 3+ /TiO2 for Cr(VI) and Cr(III) provides a new model to enhance the photocatalytic reduction of Cr(VI) anions.