Photocatalytic uranium extraction from radioactive nuclear wastewater and seawater is critical for promoting the sustainable advancement of nuclear industry,but the complexity of real-world environments,particularly t...Photocatalytic uranium extraction from radioactive nuclear wastewater and seawater is critical for promoting the sustainable advancement of nuclear industry,but the complexity of real-world environments,particularly the occurrence of anoxic and oxygen-enriched states,presents significant challenges to effective uranium extraction.Here,a layered hollow core–shell structure of Bi_(2)O_(3)/g-C_(3)N_(4)Z-scheme heterojunction photocatalyst has been designed and successfully applied for photocatalytic uranium extraction in both aerobic and oxygen-free conditions,and the extraction efficiency of uranium can reach 98.4%and 99.0%,respectively.Moreover,the photocatalyst still has ultra-high extraction efficiency under the influence of pH,inorganic ions,and other factors.The exceptional capability for uranium extraction is on the one hand due to the distinctive hollow core–shell architecture,which furnishes an abundant quantity of active sites.On the other hand,benefiting from the suitable band gap structure brought by the construction of Z-scheme heterojunction,Bi_(2)O_(3)/g-C_(3)N_(4)exhibits current densities(1.00μA/cm^(2))that are 5.26 and 3.85 times greater than Bi_(2)O_(3)and g-C_(3)N_(4),respectively,and the directional migration mode of Z-scheme carriers significantly prolongs the lifetime of photogenerated charges(1.53 ns),which separately surpass the pure samples by factors of 5.10 and 3.19.Furthermore,the reaction mechanism and reaction process of photocatalytic uranium extraction are investigated in the presence and absence of oxygen,respectively.展开更多
In this study,α-Bi2O_(3)/g-C_(3)N_(4) nanocomposite with direct Z-scheme was successfully prepared through calcination of BiOCOOH/g-C_(3)N_(4) precursor at different temperature.Meanwhile,the effect of calcination te...In this study,α-Bi2O_(3)/g-C_(3)N_(4) nanocomposite with direct Z-scheme was successfully prepared through calcination of BiOCOOH/g-C_(3)N_(4) precursor at different temperature.Meanwhile,the effect of calcination temperature on the physicochemical properties ofα-Bi2O_(3)/g-C_(3)N_(4) was studied.All results confirmed that calcination tempe rature greatly influences structural,morphology,surface states,photoelectrochemical property and photocatalytic(PC)perfo rmance ofα-Bi2O_(3)/g-C_(3)N_(4) composite.Furthermore,theα-Bi2O_(3)/gC_(3)N_(4) composite was applied as photocatalyst to degrade amido black 10 B dye under visible light irradiation.It was found that the composite synthesized at 400℃exhibited the highest PC performance due to the intense visible light absorbance and high separation efficiency of electron and hole pairs.Besides,the possible PC mechanism was proposed that the photo-generated charge carrier migration inα-Bi2O_(3)/g-C_(3)N_(4) photocatalyst followed a Z-scheme structure.Finally,the stability test also manifest that theα-Bi2O_(3)/g-C_(3)N_(4) composite photocatalyst has good stability and reusability,which was a promising candidate for wastewater treatment.展开更多
The low surface area,high recombination rate of photogenerated charge carriers,narrow visible range activity,and difficulty in the separation from cleaned solutions limit the wide application of g-C_(3)N_(4) as a phot...The low surface area,high recombination rate of photogenerated charge carriers,narrow visible range activity,and difficulty in the separation from cleaned solutions limit the wide application of g-C_(3)N_(4) as a photocatalyst.Herein,we have succeeded in developing a one-pot strategy to overcome the above-mentioned difficulties of g-C_(3)N_(4).The broadening of the visible-light response range and inducing magnetic nature to g-C_(3)N_(4) was succeeded by preparing a nanocomposite with Fe_(2)O_(3) via a facile solvothermal method.The preparation method additionally imparted layer exfoliation of g-C_(3)N_(4) as evident from the XRD patterns and TEM images.The strong interaction between the components is revealed from the XPS analysis.The broadened visible-light absorbance of Fe_(2)O_(3)/g-C_(3)N_(4) with a Z-scheme photocatalytic degradation mechanism is well evident from the UV-Vis DRS analysis and PL measurement of the composite with terephthalic acid.The active species of photocatalysis were further investigated using scavenging studies in methylene blue degradation that revealed hydroxyl radicals and holes as the major contributors to the activity of Fe_(2)O_(3)/g-C_(3)N_(4).展开更多
基金supported by the National Natural Science Foundation of China(Nos.12075066 and 21866007)the Innovation Project of Guangxi Graduate Education(No.YCBZ2022017).
文摘Photocatalytic uranium extraction from radioactive nuclear wastewater and seawater is critical for promoting the sustainable advancement of nuclear industry,but the complexity of real-world environments,particularly the occurrence of anoxic and oxygen-enriched states,presents significant challenges to effective uranium extraction.Here,a layered hollow core–shell structure of Bi_(2)O_(3)/g-C_(3)N_(4)Z-scheme heterojunction photocatalyst has been designed and successfully applied for photocatalytic uranium extraction in both aerobic and oxygen-free conditions,and the extraction efficiency of uranium can reach 98.4%and 99.0%,respectively.Moreover,the photocatalyst still has ultra-high extraction efficiency under the influence of pH,inorganic ions,and other factors.The exceptional capability for uranium extraction is on the one hand due to the distinctive hollow core–shell architecture,which furnishes an abundant quantity of active sites.On the other hand,benefiting from the suitable band gap structure brought by the construction of Z-scheme heterojunction,Bi_(2)O_(3)/g-C_(3)N_(4)exhibits current densities(1.00μA/cm^(2))that are 5.26 and 3.85 times greater than Bi_(2)O_(3)and g-C_(3)N_(4),respectively,and the directional migration mode of Z-scheme carriers significantly prolongs the lifetime of photogenerated charges(1.53 ns),which separately surpass the pure samples by factors of 5.10 and 3.19.Furthermore,the reaction mechanism and reaction process of photocatalytic uranium extraction are investigated in the presence and absence of oxygen,respectively.
基金the National Natural Science Foundation of China(Nos.5150825451978319)+2 种基金Fundamental Research Funds for the Central Universities(No.lzujbky-2017-it98)College Students’Innovative Practice Training Program of Chinese Academy of Sciences(No.Y710171040)Key Laboratory of Comprehensive and Highly Efficient Utilization of Salt Lake Resources,Qinghai Institute of Salt Lakes,Chinese Academy of Sciences。
文摘In this study,α-Bi2O_(3)/g-C_(3)N_(4) nanocomposite with direct Z-scheme was successfully prepared through calcination of BiOCOOH/g-C_(3)N_(4) precursor at different temperature.Meanwhile,the effect of calcination temperature on the physicochemical properties ofα-Bi2O_(3)/g-C_(3)N_(4) was studied.All results confirmed that calcination tempe rature greatly influences structural,morphology,surface states,photoelectrochemical property and photocatalytic(PC)perfo rmance ofα-Bi2O_(3)/g-C_(3)N_(4) composite.Furthermore,theα-Bi2O_(3)/gC_(3)N_(4) composite was applied as photocatalyst to degrade amido black 10 B dye under visible light irradiation.It was found that the composite synthesized at 400℃exhibited the highest PC performance due to the intense visible light absorbance and high separation efficiency of electron and hole pairs.Besides,the possible PC mechanism was proposed that the photo-generated charge carrier migration inα-Bi2O_(3)/g-C_(3)N_(4) photocatalyst followed a Z-scheme structure.Finally,the stability test also manifest that theα-Bi2O_(3)/g-C_(3)N_(4) composite photocatalyst has good stability and reusability,which was a promising candidate for wastewater treatment.
文摘The low surface area,high recombination rate of photogenerated charge carriers,narrow visible range activity,and difficulty in the separation from cleaned solutions limit the wide application of g-C_(3)N_(4) as a photocatalyst.Herein,we have succeeded in developing a one-pot strategy to overcome the above-mentioned difficulties of g-C_(3)N_(4).The broadening of the visible-light response range and inducing magnetic nature to g-C_(3)N_(4) was succeeded by preparing a nanocomposite with Fe_(2)O_(3) via a facile solvothermal method.The preparation method additionally imparted layer exfoliation of g-C_(3)N_(4) as evident from the XRD patterns and TEM images.The strong interaction between the components is revealed from the XPS analysis.The broadened visible-light absorbance of Fe_(2)O_(3)/g-C_(3)N_(4) with a Z-scheme photocatalytic degradation mechanism is well evident from the UV-Vis DRS analysis and PL measurement of the composite with terephthalic acid.The active species of photocatalysis were further investigated using scavenging studies in methylene blue degradation that revealed hydroxyl radicals and holes as the major contributors to the activity of Fe_(2)O_(3)/g-C_(3)N_(4).
