Efficient visible light photodegradation of BiVO_(4):Yb^(3+)/Tm^(3+)with high content of tetragonal phase  

作　　者：Han Xie Mitang Wang Zhigao Sun Xiaoyu Lu Dongliang Zhang Siqingaowa Jin Siheng Chen 

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11期135-149,共15页化学科学与工程前沿（英文版）

基　　金：National Natural Science Foundation of China(Grant No.51974168);Science and Technology Major Project of 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：In photocatalytic studies,tetragonal bismuth vanadate(t-BiVO_(4))is not promising due to its wide band gap.However,according to previous studies,the tetragonal phase is inevitable when the monoclinic bismuth vanadate(m-BiVO_(4))is modified.Therefore,it is necessary to find ways to improve the photoresponse and photocatalytic ability of t-BiVO_(4)under visible light.In this study,Yb^(3+)and Tm^(3+)co-doped BiVO_(4)was synthesized by a simple hydrothermal method,and its microstructure,morphology and optical properties were characterized and analyzed by scanning electron microscope,transmission electron microscopy,Brunauer-Emmett-Teller,X-ray diffraction,Raman,X-ray photoelectron spectroscopy,diffuse reflectance spectra,photoluminescence,upconversion luminescence and other means.The results show that BiVO_(4):Yb^(3+)/Tm^(3+)(BVYT)has a high content of tetragonal phase(about 80%),showing the characteristics of t-BiVO_(4).BVYT shows a higher separation efficiency of photogenerated carriers,its transient photocurrent response intensity increased by about 3 times,and the photocatalytic efficiency is significantly improved compare with the undoped m-BiVO_(4).Under simulated sunlight,BVYT completely degraded methylene blue(MB)solution and rhodamine B solution in 45 and 90 min,respectively,and the reaction rate was significantly improved.BVYT also shows excellent photocatalytic ability under visible light,about 35%of MB solution was degraded within 45 min under visible light irradiation(>420 nm),this is because Yb^(3+)effectively promotes the upconversion luminescence of Tm^(3+)in response to visible light,and the energy cycle mechanism of Yb-Tm-Tm is proposed.Consequently,BiVO_(4)with high content of tetragonal phase has excellent photoactivity,even exceeding m-BiVO_(4).This is a novel discovery in the field of photocatalysis,which provides a broader application prospect for BiVO_(4)in photocatalysis.

关 键 词：PHOTOCATALYSIS bismuth vanadate rare earth upconversion luminescence 

分 类 号：O643.36[理学—物理化学] O644.1[理学—化学]