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Effect of Ti ( III ) Surface Defects on the Process of Photocatalytic Reduction of Hexavalent Chromium
Author(s) -
Qin Hongxia,
Bian Yingying,
Zhang Yaxi,
Liu Longfei,
Bian Zhenfeng
Publication year - 2017
Publication title -
chinese journal of chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.28
H-Index - 41
eISSN - 1614-7065
pISSN - 1001-604X
DOI - 10.1002/cjoc.201600578
Subject(s) - hexavalent chromium , photocatalysis , chemistry , chromium , x ray photoelectron spectroscopy , adsorption , zeta potential , annealing (glass) , desorption , nuclear chemistry , inorganic chemistry , metallurgy , catalysis , chemical engineering , nanotechnology , materials science , nanoparticle , organic chemistry , engineering
In this paper, the process of photocatalytic reduction of hexavalent chromium was investigated over Ti 3+ ‐modified TiO 2 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 TiO 2 . The surface selective adsorption of hexavalent chromium [ Cr 2 O 7 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 ).