title: Relationship between surface hydroxyl groups and liquid-phase photocatalytic activity of titanium dioxide.
abstract: Both theories and experiments show that surface hydroxyl radicals (OH) are the most important intermediate species in the photocatalytic process. As a source of OH, surface hydroxyl (OH) groups play an important role in its generation. In this paper, the OH groups were divided into surface acidic hydroxyl (OH(a)) and surface basic hydroxyl (OH(b)) groups. From the detection by a method of surface acid-base, ion-exchange reactions, the total surface density of OH groups was about 9.58×10(-5) mol m(-2). The results measured by Fourier transform infrared spectroscopy, (1)H magnetic-angle spinning NMR and electron spin resonance techniques demonstrated that the role of OH(a) groups was greater than that of OH(b) groups on the generation of OH radicals. By degradation of methyl orange, rhodamine B and p-chlorophenol, the photocatalytic activities of the catalysts were directly influenced by the amount of OH groups.
authors.affiliation: Shandong Province Key Laboratory of Life-Organic Analysis, Qufu Normal University, Qufu 273165, PR China; Fujian Provincial Key Laboratory of Photocatalysis-State Key Laboratory Breeding Base, Fuzhou University, Fuzhou 350002, PR China. Electronic address: liwenjuan2801@163.com.
authors.forename: Wenjuan
authors.initials: W
authors.lastname: Li
authors.affiliation: Shandong Province Key Laboratory of Life-Organic Analysis, Qufu Normal University, Qufu 273165, PR China.
authors.forename: Dandan
authors.initials: D
authors.lastname: Du
authors.affiliation: Shandong Province Key Laboratory of Life-Organic Analysis, Qufu Normal University, Qufu 273165, PR China.
authors.forename: Tingjiang
authors.initials: T
authors.lastname: Yan
authors.affiliation: Shandong Province Key Laboratory of Life-Organic Analysis, Qufu Normal University, Qufu 273165, PR China.
authors.forename: Desheng
authors.initials: D
authors.lastname: Kong
authors.affiliation: Shandong Province Key Laboratory of Life-Organic Analysis, Qufu Normal University, Qufu 273165, PR China.
authors.forename: Jinmao
authors.initials: J
authors.lastname: You
authors.affiliation: Fujian Provincial Key Laboratory of Photocatalysis-State Key Laboratory Breeding Base, Fuzhou University, Fuzhou 350002, PR China. Electronic address: dzli@fzu.edu.cn.
authors.forename: Danzhen
authors.initials: D
authors.lastname: Li
keywords: Acidic hydroxyl (OH(a)) groups; Basic hydroxyl (OH(b)) groups; Hydroxyl radicals; Photocatalytic activity