Piezo-photocatalysis could coalesce the advantages of mechanical vibration and solar energy perfectly to achieve high-efficiency catalytic activity.Herein,the quintessential piezoelectric material CdS nanowires with d...Piezo-photocatalysis could coalesce the advantages of mechanical vibration and solar energy perfectly to achieve high-efficiency catalytic activity.Herein,the quintessential piezoelectric material CdS nanowires with different aspect ratios are precisely constructed and applied for piezo-photocatalytic reduction of U(Ⅵ)for the first time.The ultrasonic(60 kHz,100 W)induces piezoelectric potential to generate a 0.57 eV A^(-1)electric field,which is added to the direction of CdS(010)as a driving force to efficiently separate photogenerated charges.The alliance between piezoelectric effect and photocatalytic activity endows CdS NW-3 with the fastest piezo-photocatalytic rate under ultrasonic vibration and 5 W LED irradiation,and the relevant rate constant(0.042 min^(-1))is about 12 and 53.8 times than that of LED and ultrasonication.More importantly,93.74%of U(Ⅵ)could be removed from natural uranium mine wastewater.Therefore,this piezo-photocatalysis system that reduces U(Ⅵ)to easily separable(UO_(2))O_(2)·2H_(2)O(s)provides valuable input for disposal applications of radioactive wastewater and broadens the horizons of nuclear energy utilization toward the advancement of carbon neutrality.展开更多
The influence of acetate on U(Ⅵ) sorption on silica from aqueous solutions was studied at p H 2–7 by complementary experimental methods of macroscopic measurement, spectroscopic investigation and thermodynamic calcu...The influence of acetate on U(Ⅵ) sorption on silica from aqueous solutions was studied at p H 2–7 by complementary experimental methods of macroscopic measurement, spectroscopic investigation and thermodynamic calculation. Sorption percentage of U(Ⅵ) in the absence and in the presence of different acetate concentrations was determined by batch sorption procedures. Attenuated total reflection Fourier transform infra-red spectroscopy(ATR-FTIR) was used to elucidate the mechanisms of uranyl sorption on silica in the presence of acetate, by investigating, in-situ, the changes in the U(Ⅵ) sorption on silica surface in presence of ligand: the absorption bands of carboxylate ν(COO) in the range 1300–1700 cm-1and those around 850–950 cm-1of uranyl species νas(UO2) are followed. The decrease of U(Ⅵ) sorption with increasing acetate concentration was observed. Sorption of U(Ⅵ)-acetate(U-Ac) species on silica surface was demonstrated for the first time.ATR-FTIR investigations clearly evidenced the absorption bands characteristic of sorbed U-Ac complexes both from the acetate and uranyl spectral regions those the wavenumbers correspond to sorbed species. No sequence effect of acetate and uranyl on the sorption on silica in ternary systems U(Ⅵ)-acetate-silica was observed from the sorption data. From the ATR-FTIR investigations, we can induce that the sorption of U-Ac leads to chemical equilibria and makes possible the modeling of sorption isotherms by surface complexation models. The related thermodynamic constants were modeled using CCM surface complexation modeling.展开更多
基金financially supported by the National Natural Science Foundation of China(22276030,22206024,U2167223,22076022)Jiangxi Provincial Natural Science Foundation(20232BAB213034,20232ACB203011)
文摘Piezo-photocatalysis could coalesce the advantages of mechanical vibration and solar energy perfectly to achieve high-efficiency catalytic activity.Herein,the quintessential piezoelectric material CdS nanowires with different aspect ratios are precisely constructed and applied for piezo-photocatalytic reduction of U(Ⅵ)for the first time.The ultrasonic(60 kHz,100 W)induces piezoelectric potential to generate a 0.57 eV A^(-1)electric field,which is added to the direction of CdS(010)as a driving force to efficiently separate photogenerated charges.The alliance between piezoelectric effect and photocatalytic activity endows CdS NW-3 with the fastest piezo-photocatalytic rate under ultrasonic vibration and 5 W LED irradiation,and the relevant rate constant(0.042 min^(-1))is about 12 and 53.8 times than that of LED and ultrasonication.More importantly,93.74%of U(Ⅵ)could be removed from natural uranium mine wastewater.Therefore,this piezo-photocatalysis system that reduces U(Ⅵ)to easily separable(UO_(2))O_(2)·2H_(2)O(s)provides valuable input for disposal applications of radioactive wastewater and broadens the horizons of nuclear energy utilization toward the advancement of carbon neutrality.
文摘The influence of acetate on U(Ⅵ) sorption on silica from aqueous solutions was studied at p H 2–7 by complementary experimental methods of macroscopic measurement, spectroscopic investigation and thermodynamic calculation. Sorption percentage of U(Ⅵ) in the absence and in the presence of different acetate concentrations was determined by batch sorption procedures. Attenuated total reflection Fourier transform infra-red spectroscopy(ATR-FTIR) was used to elucidate the mechanisms of uranyl sorption on silica in the presence of acetate, by investigating, in-situ, the changes in the U(Ⅵ) sorption on silica surface in presence of ligand: the absorption bands of carboxylate ν(COO) in the range 1300–1700 cm-1and those around 850–950 cm-1of uranyl species νas(UO2) are followed. The decrease of U(Ⅵ) sorption with increasing acetate concentration was observed. Sorption of U(Ⅵ)-acetate(U-Ac) species on silica surface was demonstrated for the first time.ATR-FTIR investigations clearly evidenced the absorption bands characteristic of sorbed U-Ac complexes both from the acetate and uranyl spectral regions those the wavenumbers correspond to sorbed species. No sequence effect of acetate and uranyl on the sorption on silica in ternary systems U(Ⅵ)-acetate-silica was observed from the sorption data. From the ATR-FTIR investigations, we can induce that the sorption of U-Ac leads to chemical equilibria and makes possible the modeling of sorption isotherms by surface complexation models. The related thermodynamic constants were modeled using CCM surface complexation modeling.
