Enhanced photocatalytic performance by regulating the Ce^(3+)/Ce^(4+)ratio in cerium dioxide  

作　　者：Zhi Li Dongsheng Jia Wei Zhang Ying Li Mitang Wang Dongliang Zhang 

机构地区：[1]School of Materials and Chemistry,University of Shanghai for Science and Technology,Shanghai,200093,China

出　　处：《Frontiers of Chemical Science and Engineering》2024年第3期75-87,共13页化学科学与工程前沿（英文版）

基　　金：supported by National Natural Science Foundation of China(Grant No.51974168);Science and Technology Major Project Inner Mongolia Autonomous Region in China(Grant Nos.2019ZD023 and 2021ZD0028);State Key Laboratory of Silicate Materials for Architectures(Wuhan University of Technology)(Grant No.SYSJJ2020-08).

摘　　要：Cerium dioxide(CeO_(2))photocatalysts are used in treating environmental pollution and addressing the energy crisis due to their excellent oxygen storage capacities and abundant oxygen vacancies.In this paper,CeO_(2)precursors were synthesized with different water-alcohol ratios via a solvothermal method,and CeO_(2)photocatalysts with different Ce^(3+)/Ce^(4+)ratios were obtained by changing the precursor calcination atmospheres(air,Ar)as well as the calcination time.The effects of CeO_(2)with different Ce^(3+)/Ce^(4+)ratios in photocatalytic degradations of methylene blue under visible light were investigated.X-ray photoelectron spectroscopy results showed that the surfaces of the samples calcined under Ar had higher Ce^(3+)/Ce^(4+)ratios and oxygen vacancy concentrations,which reduced the band gaps of the catalysts and improved their utilization of visible light.In addition,the many Ce^(3+)/Ce^(4+)redox centers and oxygen vacancies on the sample surfaces improved the separation and transfer efficiencies of the photogenerated carriers.The sample C2-Ar calcined under Ar showed a high adsorption capacity and excellent photocatalytic activity by removing 96%of the methylene blue within 120 min,which was more than twice the degradation rate of the sample(C2-air)prepared via calcination under air.Trapping experiments showed that photogenerated holes played a key role in the photocatalytic process.In addition,a synergistic photocatalytic mechanism for the Ce^(3+)/Ce^(4+)redox centers and oxygen vacancies was elucidated in detail,and the sensitization of cerium dioxide by dyes aided the degradation of methylene blue.

关 键 词：CeO_(2) oxygen vacancies Ce^(3+)/Ce^(4+)ratios photocatalytic dye-sensitization 

分 类 号：O62[理学—有机化学]