The SnO2 quantum dots(SnO2QDs)/ZnS nanosheets(ZnSNs)heterojunction was fabricated via an in-situ synthetic method at room temperature.Rhodamine B,potassium dichromate,and tetracycline were used to discuss the photocat...The SnO2 quantum dots(SnO2QDs)/ZnS nanosheets(ZnSNs)heterojunction was fabricated via an in-situ synthetic method at room temperature.Rhodamine B,potassium dichromate,and tetracycline were used to discuss the photocatalytic activities of the as-prepared samples under the visible light illumination.The photocatalytic mechanism of the as-prepared samples was also proposed.The experimental results indicate that the degradation efficiency of the as-prepared SnO2QDs/ZnSNs heterojunction first increases and then decreases with increasing the usage of ZnSNs.When the mass ratio of SnO2QDs to ZnSNs is 1:2 in 180 min,the as-prepared samples have the highest degradation efficiency of 89.1%for rhodamine B,97.7%for potassium dichromate,and 83.8%for tetracycline,which are much higher than 51.7%,26.8%,and 0.9%of pure SnO2QDs as well as 37.9%,87.1%,and 19.1%of pure ZnSNs,respectively.After it is repeatedly degraded for 3 times,it possesses the degradation efficiency of 62.5%for rhodamine B,which increases by 200.5%in comparison with 20.8%of the pure SnO2QDs.Moreover,the enhanced photocatalytic performances of the as-prepared hybrids are attributed to the formation of heterojunction between the SnO2QDs and ZnSNs.In addition,hydroxyl radicals and superoxide anion radicals play major roles during the photocatalytic degradation process,while holes play a minor role.展开更多
The CdS/spherical g-C3N4 n-n heterojunction photocatalyst was fabricated via a solvothermal method.The tetracycline was used to characterize the photocatalytic properties of the as-developed hybrids.The photocatalytic...The CdS/spherical g-C3N4 n-n heterojunction photocatalyst was fabricated via a solvothermal method.The tetracycline was used to characterize the photocatalytic properties of the as-developed hybrids.The photocatalytic degradation mechanism of the as-developed heterojunction photocatalyst was also analyzed.Research results show that CdS nanoparticles are well dispersed in the surface layer of spherical g-C3N4.Moreover,the mass ratio of CdS to spherical g-C3N4 will influence the photocatalytic activity of the asdeveloped composites,which shows the trend of first increasing and then decreasing as it increased.When the mass ratio is 7:1,in 25 min,the as-developed heterojunction shows 93.2%of the maximum photocatalytic efficiency and still exhibits 83.6%after 5 times cycle testing.Moreover,the as-developed hybrids can accelerate the electron transport and improve the separation efficiency of photo-generated carriers compared with pure samples.In addition,the holes and superoxide radicals are dominating active species during the photocatalytic degradation process.展开更多
The SrCO3/AgI photocatalysts were prepared via a co-precipitation method by using SrCO3 as a co-photocatalyst and AgI as a photo sensitizer.X-ray diffraction,field emission scanning electron microscope,X-ray photoelec...The SrCO3/AgI photocatalysts were prepared via a co-precipitation method by using SrCO3 as a co-photocatalyst and AgI as a photo sensitizer.X-ray diffraction,field emission scanning electron microscope,X-ray photoelectron spectrometer,UV-vis diffuse reflectance spectroscopy and electrochemical impedance spectroscope were used to analyze the structure,micro-morphology,chemical compositions,optical properties and photo-generated carrier behaviors of the as-prepared samples,respectively.The photocatalytic degradation mechanism of the as-developed composites was also proposed.Analysis results show SrCO3,an insulator,can improve the photocatalytic performances and recyclability of AgI for degrading tetracycline under visible light.As the theoretical molar ratio of Sr(NO3)2 to AgNO3 increases,the degradation efficiency of the hybrids first increases and then descends.When the theoretical molar ratio of that is 1:1,it acquires the maximum of 66.6% within 8 min.This is higher than 32.0% of pure AgI and 34.0% of SrCO3.Moreover,after three times degradations it is 63.0%,which is higher than 13.6% of AgI.The improvement of the photocatalytic performance of the sample is attributed to the construction of hybrids.The main activated species in catalysis process are superoxide radicals.展开更多
基金Funded by the Natural Science Foundation of Hebei Province(Nos.E2019210251 and B2019210331)the Innovation Ability Improv-ement Project of Hebei Province(20543601D)。
文摘The SnO2 quantum dots(SnO2QDs)/ZnS nanosheets(ZnSNs)heterojunction was fabricated via an in-situ synthetic method at room temperature.Rhodamine B,potassium dichromate,and tetracycline were used to discuss the photocatalytic activities of the as-prepared samples under the visible light illumination.The photocatalytic mechanism of the as-prepared samples was also proposed.The experimental results indicate that the degradation efficiency of the as-prepared SnO2QDs/ZnSNs heterojunction first increases and then decreases with increasing the usage of ZnSNs.When the mass ratio of SnO2QDs to ZnSNs is 1:2 in 180 min,the as-prepared samples have the highest degradation efficiency of 89.1%for rhodamine B,97.7%for potassium dichromate,and 83.8%for tetracycline,which are much higher than 51.7%,26.8%,and 0.9%of pure SnO2QDs as well as 37.9%,87.1%,and 19.1%of pure ZnSNs,respectively.After it is repeatedly degraded for 3 times,it possesses the degradation efficiency of 62.5%for rhodamine B,which increases by 200.5%in comparison with 20.8%of the pure SnO2QDs.Moreover,the enhanced photocatalytic performances of the as-prepared hybrids are attributed to the formation of heterojunction between the SnO2QDs and ZnSNs.In addition,hydroxyl radicals and superoxide anion radicals play major roles during the photocatalytic degradation process,while holes play a minor role.
基金Funded by the Natural Science Foundation of Hebei Province,China(Nos.E2019210251 and B2019210331).
文摘The CdS/spherical g-C3N4 n-n heterojunction photocatalyst was fabricated via a solvothermal method.The tetracycline was used to characterize the photocatalytic properties of the as-developed hybrids.The photocatalytic degradation mechanism of the as-developed heterojunction photocatalyst was also analyzed.Research results show that CdS nanoparticles are well dispersed in the surface layer of spherical g-C3N4.Moreover,the mass ratio of CdS to spherical g-C3N4 will influence the photocatalytic activity of the asdeveloped composites,which shows the trend of first increasing and then decreasing as it increased.When the mass ratio is 7:1,in 25 min,the as-developed heterojunction shows 93.2%of the maximum photocatalytic efficiency and still exhibits 83.6%after 5 times cycle testing.Moreover,the as-developed hybrids can accelerate the electron transport and improve the separation efficiency of photo-generated carriers compared with pure samples.In addition,the holes and superoxide radicals are dominating active species during the photocatalytic degradation process.
基金Funded by the Natural Science Foundation of Hebei Province,China(Nos.E2019210251 and B2019210331)the Innovation Ability Improvement Project of Hebei Province,China(No.20543601D)the Ministry of Education"Chun Hui Plan"Cooperative Research Project,China。
文摘The SrCO3/AgI photocatalysts were prepared via a co-precipitation method by using SrCO3 as a co-photocatalyst and AgI as a photo sensitizer.X-ray diffraction,field emission scanning electron microscope,X-ray photoelectron spectrometer,UV-vis diffuse reflectance spectroscopy and electrochemical impedance spectroscope were used to analyze the structure,micro-morphology,chemical compositions,optical properties and photo-generated carrier behaviors of the as-prepared samples,respectively.The photocatalytic degradation mechanism of the as-developed composites was also proposed.Analysis results show SrCO3,an insulator,can improve the photocatalytic performances and recyclability of AgI for degrading tetracycline under visible light.As the theoretical molar ratio of Sr(NO3)2 to AgNO3 increases,the degradation efficiency of the hybrids first increases and then descends.When the theoretical molar ratio of that is 1:1,it acquires the maximum of 66.6% within 8 min.This is higher than 32.0% of pure AgI and 34.0% of SrCO3.Moreover,after three times degradations it is 63.0%,which is higher than 13.6% of AgI.The improvement of the photocatalytic performance of the sample is attributed to the construction of hybrids.The main activated species in catalysis process are superoxide radicals.
