Semiconductor photocatalysis is a novel highly efficient and low-cost method for removing organic pollutants from wastewater.However,the photoreduction performance of semiconductors on organic pollutants is limited du...Semiconductor photocatalysis is a novel highly efficient and low-cost method for removing organic pollutants from wastewater.However,the photoreduction performance of semiconductors on organic pollutants is limited due to the weak absorption of visible light caused by its wide band gap and low carrier utilization rate resulting from severe electron-holes recombination.In the present study,flower-like NH_(2)-UiO-66(NU66)/ZnO nanocomposites were prepared using a facile method and exhibited high efficiency under visible light driven photocatalysts.The X-ray diffractometer(XRD),scanning electron microscope(SEM),transmitor electron microscope(TEM),and X-ray photoelectron spectroscopy(XPS)were used to characterize the prepared samples,indicating that NU66/ZnO was successfully synthesized.The photocatalytic activity of the prepared NU66/ZnO nanocomposites was determined by measuring the photodegradation of methylene blue(MB)and malachite green(MG)under visible-light irradiation.The optimal nanocomposite loading of 5%wt NU66 to NU66/ZnO demonstrated the highest photocatalytic activity for the degradation of MB.The photocatalytic activity of a 5%NU66/ZnO composite was approximately 95-fold and 19-fold higher than that of NU66 and ZnO samples,respectively.The enhanced activity of the 5%wt NU66/ZnO nanocomposite was further confirmed through photoelectrochemical analysis.The formation of type II heterojunctions between the counterparts significantly suppressed recombination of the photogenerated charge carriers.Photocatalytic degradation experiments with different quenchers indicated that the effect of superoxide anion radicals(•O_(2)^(−))had a greater effect than the other scavengers.Additionally,the improved photocatalytic mechanism underlying the activity of NU66/ZnO nanocomposites was also explored.These findings establish a basis for development of MOF based heterojunction for photocatalytic organic pollution remediation.展开更多
N-K2Ti4O9/UiO-66-NH2 composites synthesized by a facile solvothermal method have a core-shell structure with UiO-66-NH2 forming the shell around a N-K2Ti4O9 core.Their photocatalytic activities in the degradation of d...N-K2Ti4O9/UiO-66-NH2 composites synthesized by a facile solvothermal method have a core-shell structure with UiO-66-NH2 forming the shell around a N-K2Ti4O9 core.Their photocatalytic activities in the degradation of dyes under visible light irradiation were investigated.The N-K2Ti4O9/UiO-66-NH2 composites exhibited higher photocatalytic activity than the pure components.This synergistic effect was due to the high adsorption capacity of UiO-66-NH2 and that the two components together induced an enhanced separation efficiency of photogenerated electron-hole pairs.The mass ratio of N-K2Ti4O9 to ZrCl4 of 3：7 in the composite exhibited the highest photocatalytic activity.Due to the electrostatic attraction between the negatively charged backbone of UiO-66-NH2with the positively charged groups of cationic dyes,the composites were more photocatalytically active for cationic dyes than for anionic dyes.展开更多
基金the Zhoushan Science and Technology Project(2020C21023)Zhoushan Free Trade Zone International Cooperation(2019010301)Putu District of Zhoushan Environmental Special Supporting Project(PT2020e001).
文摘Semiconductor photocatalysis is a novel highly efficient and low-cost method for removing organic pollutants from wastewater.However,the photoreduction performance of semiconductors on organic pollutants is limited due to the weak absorption of visible light caused by its wide band gap and low carrier utilization rate resulting from severe electron-holes recombination.In the present study,flower-like NH_(2)-UiO-66(NU66)/ZnO nanocomposites were prepared using a facile method and exhibited high efficiency under visible light driven photocatalysts.The X-ray diffractometer(XRD),scanning electron microscope(SEM),transmitor electron microscope(TEM),and X-ray photoelectron spectroscopy(XPS)were used to characterize the prepared samples,indicating that NU66/ZnO was successfully synthesized.The photocatalytic activity of the prepared NU66/ZnO nanocomposites was determined by measuring the photodegradation of methylene blue(MB)and malachite green(MG)under visible-light irradiation.The optimal nanocomposite loading of 5%wt NU66 to NU66/ZnO demonstrated the highest photocatalytic activity for the degradation of MB.The photocatalytic activity of a 5%NU66/ZnO composite was approximately 95-fold and 19-fold higher than that of NU66 and ZnO samples,respectively.The enhanced activity of the 5%wt NU66/ZnO nanocomposite was further confirmed through photoelectrochemical analysis.The formation of type II heterojunctions between the counterparts significantly suppressed recombination of the photogenerated charge carriers.Photocatalytic degradation experiments with different quenchers indicated that the effect of superoxide anion radicals(•O_(2)^(−))had a greater effect than the other scavengers.Additionally,the improved photocatalytic mechanism underlying the activity of NU66/ZnO nanocomposites was also explored.These findings establish a basis for development of MOF based heterojunction for photocatalytic organic pollution remediation.
基金supported by the National Natural Science Foundation of China (51372062)the Anhui Provincial Natural Science Foundation(1508085MB28,1308085MB21)~~
文摘N-K2Ti4O9/UiO-66-NH2 composites synthesized by a facile solvothermal method have a core-shell structure with UiO-66-NH2 forming the shell around a N-K2Ti4O9 core.Their photocatalytic activities in the degradation of dyes under visible light irradiation were investigated.The N-K2Ti4O9/UiO-66-NH2 composites exhibited higher photocatalytic activity than the pure components.This synergistic effect was due to the high adsorption capacity of UiO-66-NH2 and that the two components together induced an enhanced separation efficiency of photogenerated electron-hole pairs.The mass ratio of N-K2Ti4O9 to ZrCl4 of 3：7 in the composite exhibited the highest photocatalytic activity.Due to the electrostatic attraction between the negatively charged backbone of UiO-66-NH2with the positively charged groups of cationic dyes,the composites were more photocatalytically active for cationic dyes than for anionic dyes.
