The g-C3N4/Ag/GO(CNAG)photocatalysts were synthesized by a facile two-step reaction route.The as-prepared CNAG samples were characterized by X-ray diffraction(XRD),Fourier transform-infrared spectroscopy(FTIR),X-ray p...The g-C3N4/Ag/GO(CNAG)photocatalysts were synthesized by a facile two-step reaction route.The as-prepared CNAG samples were characterized by X-ray diffraction(XRD),Fourier transform-infrared spectroscopy(FTIR),X-ray photoelectron spectroscopy(XPS),photoluminescence spectroscopy(PL)and ultraviolet-visible diffuse reflectance spectroscopy techniques(UV-vis DRS).The photocatalytic activity was obtained by degrading rhodamine B(RhB)under simulated sunlight and the results showed that photocatalytic activity of CNAG was much higher than that of pure g-C3N4 and g-C3N4/Ag.When the mass ratio of GO was 6%,the as-prepared CNAG-6%sample possessed the highest photocatalytic activity and the kinetic constant of RhB degradation was 0.077 min-1,which was almost 4.3 times higher than that of pure g-C3N4(0.018 min-1)and 2.5 times higher than that of the g-C3N4/Ag(0.031 min-1)composite,respectively.The toxicity of CNAG samples was assessed via seed germination experiment and no significant inhibitory effect was observed.The enhanced photocatalytic activity could be attributed to the synergistic effect of partial surface plasma resonance(SPR)effect of Ag,strong visible light absorption and the high separation efficiency of photon-generated carrier.The CNAG-6%sample exhibited excellent stability during the cycle experiment.Finally,a possible photocatalytic mechanism was proposed.展开更多
Two kinetic models were established for conservative estimates of photodegradation rates of contaminants under sunlight irradiation,in particular for wastewater stabilisation ponds and clarifiers in conventional waste...Two kinetic models were established for conservative estimates of photodegradation rates of contaminants under sunlight irradiation,in particular for wastewater stabilisation ponds and clarifiers in conventional wastewater treatment plants.These two models were designated for(1)contaminants with high photolytic rates or high photolytic quantum yields,whose photodegradation is unlikely to be enhanced by aquatic photosensitisers;and(2)contaminants withstanding direct photolysis in sunlit waters but subjected to indirect photolysis.The effortlessly intelligible prediction procedure involves sampling and analysis of real water samples,simulated solar experiments in the laboratory,and transfer of the laboratory results to realise water treatment using the prediction models.Although similar models have been widely used for laboratory studies,this paper provides a preliminary example of translating laboratory results to the photochemical fate of contaminants in real waters.展开更多
In order to investigate the catalytic performance of anodic TiO2 nanotubes and their practical application in the treatment of refractory microcystins(MCs) in natural-water samples,TiO2 nanotubes of diameter of 50-80 ...In order to investigate the catalytic performance of anodic TiO2 nanotubes and their practical application in the treatment of refractory microcystins(MCs) in natural-water samples,TiO2 nanotubes of diameter of 50-80 nm were fabricated by anodization in C2H2O4·2H2O containing NH4F.Under irradiation with natural sunlight,MC-LR was totally degraded after 1 d using the anodic TiO2 nanotubes.In contrast,the removal efficiency without TiO2 nanotubes was as low as 47.7% within 20 d.In addition,a mixture of anatase and rutile TiO2 gave higher photocatalytic activity than the single phase did.The pH also influenced the adsorption capacity of the TiO2 nanotubes.The order of MC-LR degradation efficiencies at different pH values was 3.5 > 8.0 > 10.0.After five repeated experiments on the degradation of MC-LR for 7 h,the degradation efficiency was still stable.展开更多
Three-dimensional CuS hierarchical crystals with high catalytic activity had been successfully fabricated using a facile solvothermal process, The CuS microparticles showed different flower-like morphology and good di...Three-dimensional CuS hierarchical crystals with high catalytic activity had been successfully fabricated using a facile solvothermal process, The CuS microparticles showed different flower-like morphology and good dispersion by optimizing reaction conditions. It was found that using N,N-dimethylformamide （DMF） as the solvent reagent in the proper temperature conditions was favorable for the growth of hierarchically structured CuS. The hexagonal flower-like CuS synthesized at 170℃ for 60 min displayed broad-spectrum photocatalytic properties under ultraviolet （UV） and visible irradiation. The as-prepared CuS crystals exhibited good performance to decolorize methylene blue （MB） solution under visible light irradiation. The total organic carbon （TOC） removal of rhodamine B （RhB） solution was nearly 60% after 5 h of the natural sunlight irradiation, and the property was stable after testing over four recycles, demonstrating a potential application in waster water treatment.展开更多
基金supported by the National Natural Science Foundation of China(11374080)。
文摘The g-C3N4/Ag/GO(CNAG)photocatalysts were synthesized by a facile two-step reaction route.The as-prepared CNAG samples were characterized by X-ray diffraction(XRD),Fourier transform-infrared spectroscopy(FTIR),X-ray photoelectron spectroscopy(XPS),photoluminescence spectroscopy(PL)and ultraviolet-visible diffuse reflectance spectroscopy techniques(UV-vis DRS).The photocatalytic activity was obtained by degrading rhodamine B(RhB)under simulated sunlight and the results showed that photocatalytic activity of CNAG was much higher than that of pure g-C3N4 and g-C3N4/Ag.When the mass ratio of GO was 6%,the as-prepared CNAG-6%sample possessed the highest photocatalytic activity and the kinetic constant of RhB degradation was 0.077 min-1,which was almost 4.3 times higher than that of pure g-C3N4(0.018 min-1)and 2.5 times higher than that of the g-C3N4/Ag(0.031 min-1)composite,respectively.The toxicity of CNAG samples was assessed via seed germination experiment and no significant inhibitory effect was observed.The enhanced photocatalytic activity could be attributed to the synergistic effect of partial surface plasma resonance(SPR)effect of Ag,strong visible light absorption and the high separation efficiency of photon-generated carrier.The CNAG-6%sample exhibited excellent stability during the cycle experiment.Finally,a possible photocatalytic mechanism was proposed.
文摘Two kinetic models were established for conservative estimates of photodegradation rates of contaminants under sunlight irradiation,in particular for wastewater stabilisation ponds and clarifiers in conventional wastewater treatment plants.These two models were designated for(1)contaminants with high photolytic rates or high photolytic quantum yields,whose photodegradation is unlikely to be enhanced by aquatic photosensitisers;and(2)contaminants withstanding direct photolysis in sunlit waters but subjected to indirect photolysis.The effortlessly intelligible prediction procedure involves sampling and analysis of real water samples,simulated solar experiments in the laboratory,and transfer of the laboratory results to realise water treatment using the prediction models.Although similar models have been widely used for laboratory studies,this paper provides a preliminary example of translating laboratory results to the photochemical fate of contaminants in real waters.
基金supported by the National Natural Science Foundation of China (20906097)the Natural Science Foundation of Jiangsu Province,China (BK2011881)
文摘In order to investigate the catalytic performance of anodic TiO2 nanotubes and their practical application in the treatment of refractory microcystins(MCs) in natural-water samples,TiO2 nanotubes of diameter of 50-80 nm were fabricated by anodization in C2H2O4·2H2O containing NH4F.Under irradiation with natural sunlight,MC-LR was totally degraded after 1 d using the anodic TiO2 nanotubes.In contrast,the removal efficiency without TiO2 nanotubes was as low as 47.7% within 20 d.In addition,a mixture of anatase and rutile TiO2 gave higher photocatalytic activity than the single phase did.The pH also influenced the adsorption capacity of the TiO2 nanotubes.The order of MC-LR degradation efficiencies at different pH values was 3.5 > 8.0 > 10.0.After five repeated experiments on the degradation of MC-LR for 7 h,the degradation efficiency was still stable.
基金We are grateful for the financial support from the National Natural Science Foundation of China （Grant No. 51202156）.
文摘Three-dimensional CuS hierarchical crystals with high catalytic activity had been successfully fabricated using a facile solvothermal process, The CuS microparticles showed different flower-like morphology and good dispersion by optimizing reaction conditions. It was found that using N,N-dimethylformamide （DMF） as the solvent reagent in the proper temperature conditions was favorable for the growth of hierarchically structured CuS. The hexagonal flower-like CuS synthesized at 170℃ for 60 min displayed broad-spectrum photocatalytic properties under ultraviolet （UV） and visible irradiation. The as-prepared CuS crystals exhibited good performance to decolorize methylene blue （MB） solution under visible light irradiation. The total organic carbon （TOC） removal of rhodamine B （RhB） solution was nearly 60% after 5 h of the natural sunlight irradiation, and the property was stable after testing over four recycles, demonstrating a potential application in waster water treatment.
