The nanophotocatalysts were synthesized in four stages and evaluated by FTIR, FESEM and VSM analysis. The influence of nanofluids containing functionalized magnetic Ti O2 nanophotocatalyst and dipalmitoylphosphatidylc...The nanophotocatalysts were synthesized in four stages and evaluated by FTIR, FESEM and VSM analysis. The influence of nanofluids containing functionalized magnetic Ti O2 nanophotocatalyst and dipalmitoylphosphatidylcholine lecithin in drag reduction of turbulent flow in four horizontal pipelines was studied. The effective parameters on drag reduction(nanoparticle concentration, surfactant concentration, p H and Re number) were investigated and optimized in each pipeline using response surface method. The drag reduction in 1/2 " galvanized, 3/4" galvanized, 1/2 "five-layer and 1/2" cuprous pipelines was found 99.1%, 92.5%, 87.6% and 85.2%, respectively. The model adequacy was measured using ANOVA. Based on the high determination coefficient, more than 95% of variance of experimental data in all pipelines was described by quadratic model.展开更多
The photocatalytic degradation of reactive blue 19(RB19)dye was investigated in a slurry system using ultraviolet(UV)and light-emitting diode(LED)lamps as light sources and using magnetic tungsten trioxide nanophotoca...The photocatalytic degradation of reactive blue 19(RB19)dye was investigated in a slurry system using ultraviolet(UV)and light-emitting diode(LED)lamps as light sources and using magnetic tungsten trioxide nanophotocatalysts(α-Fe_(2)O_(3)/WO_(3)and WO_(3)/NaOH)as photocatalysts.The effects of different parameters including irradiation time,initial concentration of RB19,nanophotocatalyst dosage,and pH were examined.The magnetic nanophotocatalysts were also characterized with different methods including scanning electron microscopy(SEM),energy-dispersive X-ray spectroscopy(EDS),transmission electron microscopy(TEM),X-ray diffraction(XRD),photoluminescence(PL),differen-tial reflectance spectroscopy(DRS),Fourier transform infrared spectroscopy(FTIR),and vibrating sample magnetometry(VSM).The XRD and FTIR analyses confirmed the presence of tungsten trioxide on the iron oxide nanoparticles.The VSM analysis confirmed the magnetic ability of the new synthesized nanophotocatalyst α-Fe_(2)O_(3)/WO_(3)with 39.6 emu/g of saturation magnetization.The reactor performance showed consid-erable improvement in the α-Fe_(2)O_(3)-modified nanophotocatalyst.The impact of visible light was specifically investigated,and it was compared with UV-C light under the same experimental conditions.The reusability of the magnetic nanophotocatalyst α-Fe_(2)O_(3)/WO_(3)was tested during six cycles,and the magnetic materials showed an excellent removal efficiency after six cycles,with just a 7%decline.展开更多
Graphene quantum dots （GODs） recently emerge as the new and appealing nanophotocatalyst because of their low-cost, environmental compatibility and the ability to facilitate the charge migration and prolong the charg...Graphene quantum dots （GODs） recently emerge as the new and appealing nanophotocatalyst because of their low-cost, environmental compatibility and the ability to facilitate the charge migration and prolong the charge lifetimes. In this work, a visible photocatalyst of S-doped graphene quantum dots （S-GQDs） was prepared by a facile hydrothermal synthesis using 1,3,6-trinitropyrene and Na2S as precursors. The well crystallization and monodispersity as well as the chemical environment of S-GQDs were characterized by transmission electron microscopy, atom force microscopy and X-ray photoelectron spectrum. A superior photocatalytic performance of S-GQDs was demonstrated for degradation of basic fuchsin under visible light irradiation. Furthermore, the possible photocatalytic mechanism was proposed based on the trapping experiments of active species.展开更多
Several nanoporous Fe2 O3-xSx/S-doped g-C3 N4（CNS） Z-scheme hybrid heterojuctions have been successfully synthesized by one-pot in situ growth of the Fe2O3-xSx particles on the surface of CNS. The characterization r...Several nanoporous Fe2 O3-xSx/S-doped g-C3 N4（CNS） Z-scheme hybrid heterojuctions have been successfully synthesized by one-pot in situ growth of the Fe2O3-xSx particles on the surface of CNS. The characterization results show that S-doping in the g-C3 N4 backbone can greatly enhance the charge mobility and visible light harvesting capability. In addition, porous morphology of hybrid composite provides available open pores for guest molecules and also improves light absorbing property due to existence of multiple scattering effects. More importantly, the Fe2 O3-xSx nanoparticles formed intimate heterojunction with CNS and developed the efficient charge transfer by extending interfacial interactions occurred at the interfaces of both components. It has been found that the Fe2 O3-xSx/CNS composites have an enhanced photocatalytic activity under visible light irradiation compared with isolated Fe2 O3 and CNS components toward the photocatalytic degradation of methylene blue（MB）. The optimal loaded Fe2 O3-xSx value obtained is equal to 6.6 wt% that provided 82% MB photodegradation after 150 min with a reaction rate constant of 0.0092 min（-1） which was faster than those of the pure Fe2 O3（0.0016 min（-1））and CNS（0.0044 min（-1）） under the optimized operating variables acquired by the response surface methodology. The specific surface area and the pore volume of Fe2 O3（6.6）/CNS hybrid are 33.5 m2/g and0.195 cm3/g, which are nearly 3.8 and 7.5 times greater compared with those of the CNS, respectively. The TEM image of Fe2 O3（6.6）/CNS nanocomposite exhibits a nanoporous morphology with abundant uniform pore sizes of around 25 nm. Using the Mott-Schottky plot, the conduction and valence bands of the CNS are measured（at pH = 7） equal to-1.07 and 1.48 V versus normal hydrogen electrode（NHE）, respectively.Trapping tests prove that ·OH-and ·O2-radicals are major active species in the photocatalytic reaction.It has been established that formation of the Z-scheme Fe2 O3（6.6）/CNS heterojunction between CNS and Fe2 O3 directly produces ·OH as well as ·O2-radicals which is consistent with the results obtained from trapping experiments.展开更多
Nanophotocatalysts have shown great potential for degrading poly-and perfluorinated substances(PFAS).In light of the fact that most of these catalysts were studied in pure water,this study was designed to elucidate ef...Nanophotocatalysts have shown great potential for degrading poly-and perfluorinated substances(PFAS).In light of the fact that most of these catalysts were studied in pure water,this study was designed to elucidate effects from common environmental factors on decomposing and defluorinating perfluorooctanoic acid(PFOA)by In2O3 nanoparticles.Results from this work demonstrated that among the seven parameters,pH,sulfate,chloride,H2O2,In2O3 dose,NOM and O2,the first four had statistically significant negative effects on PFOA degradation.Since PFOA is a strong acid,the best condition leading to the highest PFOA removal was identified for two pH ranges.When pH was between 4 and 8,the optimal condition was:pH=4.2;sulfate=5.00 mg/L;chloride=20.43 mg/L;H2O2=0 mmol/L.Under this condition,PFOA decomposition and defluorination were 55.22 and 23.56%,respectively.When pH was between 2 and 6,the optimal condition was:pH=2;sulfate=5.00 mg/L;chloride=27.31 mg/L;H2O2=0 mmol/L.With this condition,the modeled PFOA decomposition was 97.59%with a defluorination of approximately 100%.These predicted results were all confirmed by experimental data.Thus,In2O3 nanoparticles can be used for degrading PFOA in aqueous solutions.This approach works best when the target contaminated water contains low concentrations of NOM,sulfate and chloride and at a low pH.展开更多
文摘The nanophotocatalysts were synthesized in four stages and evaluated by FTIR, FESEM and VSM analysis. The influence of nanofluids containing functionalized magnetic Ti O2 nanophotocatalyst and dipalmitoylphosphatidylcholine lecithin in drag reduction of turbulent flow in four horizontal pipelines was studied. The effective parameters on drag reduction(nanoparticle concentration, surfactant concentration, p H and Re number) were investigated and optimized in each pipeline using response surface method. The drag reduction in 1/2 " galvanized, 3/4" galvanized, 1/2 "five-layer and 1/2" cuprous pipelines was found 99.1%, 92.5%, 87.6% and 85.2%, respectively. The model adequacy was measured using ANOVA. Based on the high determination coefficient, more than 95% of variance of experimental data in all pipelines was described by quadratic model.
基金The work was supported by the Fund of Kharazmi University(Grant No.22073).
文摘The photocatalytic degradation of reactive blue 19(RB19)dye was investigated in a slurry system using ultraviolet(UV)and light-emitting diode(LED)lamps as light sources and using magnetic tungsten trioxide nanophotocatalysts(α-Fe_(2)O_(3)/WO_(3)and WO_(3)/NaOH)as photocatalysts.The effects of different parameters including irradiation time,initial concentration of RB19,nanophotocatalyst dosage,and pH were examined.The magnetic nanophotocatalysts were also characterized with different methods including scanning electron microscopy(SEM),energy-dispersive X-ray spectroscopy(EDS),transmission electron microscopy(TEM),X-ray diffraction(XRD),photoluminescence(PL),differen-tial reflectance spectroscopy(DRS),Fourier transform infrared spectroscopy(FTIR),and vibrating sample magnetometry(VSM).The XRD and FTIR analyses confirmed the presence of tungsten trioxide on the iron oxide nanoparticles.The VSM analysis confirmed the magnetic ability of the new synthesized nanophotocatalyst α-Fe_(2)O_(3)/WO_(3)with 39.6 emu/g of saturation magnetization.The reactor performance showed consid-erable improvement in the α-Fe_(2)O_(3)-modified nanophotocatalyst.The impact of visible light was specifically investigated,and it was compared with UV-C light under the same experimental conditions.The reusability of the magnetic nanophotocatalyst α-Fe_(2)O_(3)/WO_(3)was tested during six cycles,and the magnetic materials showed an excellent removal efficiency after six cycles,with just a 7%decline.
基金financial support from the Zhejiang Provincial Natural Science Foundation of China (Nos. LY17B050007, LY15B050006)521 Talent Project of ZSTU
文摘Graphene quantum dots （GODs） recently emerge as the new and appealing nanophotocatalyst because of their low-cost, environmental compatibility and the ability to facilitate the charge migration and prolong the charge lifetimes. In this work, a visible photocatalyst of S-doped graphene quantum dots （S-GQDs） was prepared by a facile hydrothermal synthesis using 1,3,6-trinitropyrene and Na2S as precursors. The well crystallization and monodispersity as well as the chemical environment of S-GQDs were characterized by transmission electron microscopy, atom force microscopy and X-ray photoelectron spectrum. A superior photocatalytic performance of S-GQDs was demonstrated for degradation of basic fuchsin under visible light irradiation. Furthermore, the possible photocatalytic mechanism was proposed based on the trapping experiments of active species.
基金financial supports from the Research Office of Amirkabir University of Technology (Tehran Polytechnic)
文摘Several nanoporous Fe2 O3-xSx/S-doped g-C3 N4（CNS） Z-scheme hybrid heterojuctions have been successfully synthesized by one-pot in situ growth of the Fe2O3-xSx particles on the surface of CNS. The characterization results show that S-doping in the g-C3 N4 backbone can greatly enhance the charge mobility and visible light harvesting capability. In addition, porous morphology of hybrid composite provides available open pores for guest molecules and also improves light absorbing property due to existence of multiple scattering effects. More importantly, the Fe2 O3-xSx nanoparticles formed intimate heterojunction with CNS and developed the efficient charge transfer by extending interfacial interactions occurred at the interfaces of both components. It has been found that the Fe2 O3-xSx/CNS composites have an enhanced photocatalytic activity under visible light irradiation compared with isolated Fe2 O3 and CNS components toward the photocatalytic degradation of methylene blue（MB）. The optimal loaded Fe2 O3-xSx value obtained is equal to 6.6 wt% that provided 82% MB photodegradation after 150 min with a reaction rate constant of 0.0092 min（-1） which was faster than those of the pure Fe2 O3（0.0016 min（-1））and CNS（0.0044 min（-1）） under the optimized operating variables acquired by the response surface methodology. The specific surface area and the pore volume of Fe2 O3（6.6）/CNS hybrid are 33.5 m2/g and0.195 cm3/g, which are nearly 3.8 and 7.5 times greater compared with those of the CNS, respectively. The TEM image of Fe2 O3（6.6）/CNS nanocomposite exhibits a nanoporous morphology with abundant uniform pore sizes of around 25 nm. Using the Mott-Schottky plot, the conduction and valence bands of the CNS are measured（at pH = 7） equal to-1.07 and 1.48 V versus normal hydrogen electrode（NHE）, respectively.Trapping tests prove that ·OH-and ·O2-radicals are major active species in the photocatalytic reaction.It has been established that formation of the Z-scheme Fe2 O3（6.6）/CNS heterojunction between CNS and Fe2 O3 directly produces ·OH as well as ·O2-radicals which is consistent with the results obtained from trapping experiments.
基金funding provided by University at Albany,State University of New York。
文摘Nanophotocatalysts have shown great potential for degrading poly-and perfluorinated substances(PFAS).In light of the fact that most of these catalysts were studied in pure water,this study was designed to elucidate effects from common environmental factors on decomposing and defluorinating perfluorooctanoic acid(PFOA)by In2O3 nanoparticles.Results from this work demonstrated that among the seven parameters,pH,sulfate,chloride,H2O2,In2O3 dose,NOM and O2,the first four had statistically significant negative effects on PFOA degradation.Since PFOA is a strong acid,the best condition leading to the highest PFOA removal was identified for two pH ranges.When pH was between 4 and 8,the optimal condition was:pH=4.2;sulfate=5.00 mg/L;chloride=20.43 mg/L;H2O2=0 mmol/L.Under this condition,PFOA decomposition and defluorination were 55.22 and 23.56%,respectively.When pH was between 2 and 6,the optimal condition was:pH=2;sulfate=5.00 mg/L;chloride=27.31 mg/L;H2O2=0 mmol/L.With this condition,the modeled PFOA decomposition was 97.59%with a defluorination of approximately 100%.These predicted results were all confirmed by experimental data.Thus,In2O3 nanoparticles can be used for degrading PFOA in aqueous solutions.This approach works best when the target contaminated water contains low concentrations of NOM,sulfate and chloride and at a low pH.
