Modification of BiVO4/Ag3VO4 by Bi2O3:Determinations of surface properties and photocatalytic activities

Autor: Guo-Yi Li, 李國翊
Rok vydání: 2019
Druh dokumentu: 學位論文 ; thesis
Popis: 107
BiVO4/Ag3VO4 coupled-photocataltst was prepared by hydrothermal method permeation liquidliquid one-step process with BiVO4/Ag3VO4 molar ratio of 1 and was denoted as BA-1. BiVO4/Ag3VO4/Bi2O3 coupled-photocataltst was generated by hydrothermal method permeation liquid-liquid-liquid one-step process with BiVO4/Ag3VO4/Bi2O3 molar ratio of 1/1/1 and was denoted as BBA-1. Adding BA-1 to Bi2O3 precursor solution with BiVO4/Ag3VO4/Bi2O3 molar ratio of 1/1/1 by sovolthermal method, the generated coupled-photocataltst was noted as BBA-7. C.I. Reactive Red 2 (RR2) was selected as the target compound. The surface characteristics and photocatalytic activities of prepared photocatalysts were determined and compared in this study. The surface properties of photocatalysts were characterized by X-ray diffraction (XRD), brunauer Emmett teller (BET), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-Vis spectroscopy (UV-Vis), photoluminescence (PL), inductively coupled plasma optical emission spectrometry (ICP-OES), zeta potential meter and X-ray photoelectron spectroscopy (XPS). After 60 minutes of UV irradiation, the RR2 removal efficiency of Ag3VO4 was 97%, the RR2 removal percentage of BA-1 and BBA-1 was 92% and 99%, respectively; after 60 minutes of visible light irradiation, the RR2 removal efficiency of Ag3VO4 was 10%, the RR2 removal percentage of BA-1 and BBA-1 were 82% and 97%, respectively. The experimental results of active oxidation species trapping revealed that hydroxyl radicals could be ignored in BA-1, BBA-1 and BBA-7 system, conversely, the photogenerated hole (h+) played a major role and photoinduced electrons played a minor role in the BA-1, BBA-1 and BBA-7 system. The ICP-OES results showed that BA- 1, BBA-1 and BBA-7 under UV light irradiation showed the Ag dissolution ratio after three times photocatalysis was 9.33%, 36.2% and 16.6%. The used BA-1, BBA-1 and BBA-7 were characterized by SEM and found the structure of the used Ag3VO4 collapsed. According to the SEM and TEM observation, the used BA-1 showed that Ag3VO4 was remain immobilized on the surface of BiVO4 and the structure was not destroyed. After three times photocatalysis, the specific surface area of BA- 1 increased from 4.21 m2/g to 6.95 m2/g; BBA-1 increased from 10.22 m2/g to 12.43 m2/g and BBA- 7 increased from 11.34 m2/g to 11.69 m2/g. Keywords: BiVO4; Ag3VO4; Bi2O3; photocatalyst; photodegradation
Databáze: Networked Digital Library of Theses & Dissertations
Externí odkaz: