title: The Effect of pH Values on the Synthesis, Microstructure and Photocatalytic Activity of Ce-Bi2 O3 by a Two-Step Hydrothermal Method.
abstract: In this study, the effect of pH values on the microstructure and photocatalytic activity of Ce-Bi2 O3 under visible light irradiation was investigated in detail. In alkaline condition (e.g. pH = 9), the as-prepared Ce-Bi2 O3 exhibited an agglomerated status and mesoporous structures without a long-range order. While in weak acid condition (e.g. pH = 5), the Ce-Bi2 O3 exhibited a best morphology with irregular nanosheets. Correspondingly, it possessed largest surface area (24.641 m(2)  g(-1) ) and pore volume (9.825E-02 cm(3)  g(-1) ). These unique nanosheets can offer an attachment for pollutant molecules and reduce the distance of electron immigration from inner to surface, thus facilitating the separation of photoelectron and hole pairs. Compared with the pure Bi2 O3 , the band gap of Ce-Bi2 O3 prepared at different pH was much lower. Among them, the band gap of Ce-Bi2 O3 (pH of 5) was lowest (2.61 eV). Ce-Bi2 O3 (pH of 5) exhibited as tetragonal crystal with the bismuth oxide in the form of the composites, which could reduce the band gap width or suppress the charge-carrier recombination, subsequently possessing great photocatalytic activity for acid orange II under visible light irradiation. After 2 h degradation under visible light, the degradation rate of acid Orange II was up to 96.44% by Ce-Bi2 O3 prepared at pH 5. Overall, it can be concluded that the pH values had effects on the microstructure and photocatalytic activity of Ce-Bi2 O3 catalysts.
authors.affiliation: Key Laboratory of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun, China.
authors.forename: Fengjun
authors.initials: F
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Lu
authors.affiliation: Key Laboratory of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun, China.
authors.forename: Guosheng
authors.initials: G
authors.lastname: Xiao
authors.affiliation: Key Laboratory of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun, China.|Guangdong Huanqiu Contracting & Engineering Corporation, Guangzhou, China.
authors.forename: Zhuojing
authors.initials: Z
authors.lastname: Liu
authors.affiliation: Key Laboratory of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun, China.
authors.forename: Fanwei
authors.initials: F
authors.lastname: Xing
authors.affiliation: Key Laboratory of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun, China.
authors.forename: Cong
authors.initials: C
authors.lastname: Lyu