Hollow Bi2WO6 microspheres are successfully synthesized by a facile ultrasonic spray pyrolysis（USP） method using NaCl as a salt template.The as-prepared hollow microspheres assembled as nanoplates with dimensions of...Hollow Bi2WO6 microspheres are successfully synthesized by a facile ultrasonic spray pyrolysis（USP） method using NaCl as a salt template.The as-prepared hollow microspheres assembled as nanoplates with dimensions of approximately 41-148 nm and are dispersed with non-uniform pores on the template surface.By swapping the salt template with KC1 or Na2SO4,different morphologies of Bi2WO6 are obtained.The experimental results demonstrate that NaCl plays a key role on the formation of Bi2WO6 with hollow structures.The specific growth mechanism of hollow microspheres was studied in detail.The Bi2WO6 hollow microspheres exhibit an excellent photocatalytic efficiency for NO removal under solar light irradiation,which is 1.73 times higher than for the Bi2WO6 obtained in the absence of any salt template.This enhancement can be ascribed to the simultaneous improvement on the surface area and visible light-harvesting ability from the hollow structures.Electron spin resonance（ESR） results suggest that both radicals of ·OH and ·O2^- are involved in the photocatalytic process over the BWO-NaCl sample.The production of ·O2^- radicals offers better durability for NO removal.展开更多
A synergistic UV/TiO2/Fenton(PCF)process is investigated for the degradation of ibuprofen(IBP)at circumneutral pH.The IBP decay in the PCF process is much faster than that with the conventional UV,UV/H2O2,Fenton,photo...A synergistic UV/TiO2/Fenton(PCF)process is investigated for the degradation of ibuprofen(IBP)at circumneutral pH.The IBP decay in the PCF process is much faster than that with the conventional UV,UV/H2O2,Fenton,photo‐Fenton,and photocatalysis processes.The kinetics analysis showed that the IBP decay follows a two‐stage pseudo‐first order profile,that is,a fast IBP decay(k1)followed by a slow decay(k2).The effects of various parameters,including initial pH level,dosage of Fenton’s reagent and TiO2,wavelength of UV irradiation,and initial IBP concentration,are evaluated.The optimum pH level,[Fe2+]0,[Fe2+]0/[H2O2]0 molar ratio,and[TiO2]0 are determined to be approximately 4.22,0.20 mmol/L,1/40,and 1.0 g/L,respectively.The IBP decay at circumneutral pH(i.e.,6.0–8.0 for wastewater)shows the same IBP decay efficiency as that at the optimum pH of 4.22 after 30 min,which suggests that the PCF process is applicable for the treatment of wastewater in the circumneutral pH range.The lnk1 and lnk2 are observed to be linearly correlated to 1/pH0,[IBP]0,[H2O2]0,[H2O2]0/[Fe2+]0 and ln[TiO2]0.Mathematical models are therefore derived to predict the IBP decay.展开更多
基金supported by the National Natural Science Foundation of China (41503102, 41401567, 41573138)the China Postdoctoral Science Foundation (2015M572568)~~
文摘Hollow Bi2WO6 microspheres are successfully synthesized by a facile ultrasonic spray pyrolysis（USP） method using NaCl as a salt template.The as-prepared hollow microspheres assembled as nanoplates with dimensions of approximately 41-148 nm and are dispersed with non-uniform pores on the template surface.By swapping the salt template with KC1 or Na2SO4,different morphologies of Bi2WO6 are obtained.The experimental results demonstrate that NaCl plays a key role on the formation of Bi2WO6 with hollow structures.The specific growth mechanism of hollow microspheres was studied in detail.The Bi2WO6 hollow microspheres exhibit an excellent photocatalytic efficiency for NO removal under solar light irradiation,which is 1.73 times higher than for the Bi2WO6 obtained in the absence of any salt template.This enhancement can be ascribed to the simultaneous improvement on the surface area and visible light-harvesting ability from the hollow structures.Electron spin resonance（ESR） results suggest that both radicals of ·OH and ·O2^- are involved in the photocatalytic process over the BWO-NaCl sample.The production of ·O2^- radicals offers better durability for NO removal.
文摘A synergistic UV/TiO2/Fenton(PCF)process is investigated for the degradation of ibuprofen(IBP)at circumneutral pH.The IBP decay in the PCF process is much faster than that with the conventional UV,UV/H2O2,Fenton,photo‐Fenton,and photocatalysis processes.The kinetics analysis showed that the IBP decay follows a two‐stage pseudo‐first order profile,that is,a fast IBP decay(k1)followed by a slow decay(k2).The effects of various parameters,including initial pH level,dosage of Fenton’s reagent and TiO2,wavelength of UV irradiation,and initial IBP concentration,are evaluated.The optimum pH level,[Fe2+]0,[Fe2+]0/[H2O2]0 molar ratio,and[TiO2]0 are determined to be approximately 4.22,0.20 mmol/L,1/40,and 1.0 g/L,respectively.The IBP decay at circumneutral pH(i.e.,6.0–8.0 for wastewater)shows the same IBP decay efficiency as that at the optimum pH of 4.22 after 30 min,which suggests that the PCF process is applicable for the treatment of wastewater in the circumneutral pH range.The lnk1 and lnk2 are observed to be linearly correlated to 1/pH0,[IBP]0,[H2O2]0,[H2O2]0/[Fe2+]0 and ln[TiO2]0.Mathematical models are therefore derived to predict the IBP decay.
