A series of UiO-66-NH2/Ag2CO3 Z-scheme heterojunctions were prepared by a simple ion-exchange-solution method using UiO-66-NH2 and semiconductor Ag2CO3 as precursors.The photocatalytic activities of UAC-X(UAC-20,50,10...A series of UiO-66-NH2/Ag2CO3 Z-scheme heterojunctions were prepared by a simple ion-exchange-solution method using UiO-66-NH2 and semiconductor Ag2CO3 as precursors.The photocatalytic activities of UAC-X(UAC-20,50,100,150,200)Z-scheme heterojunctions toward the hexavalent chromium(Cr(VI))reduction and UAC-100 toward oxidative degradation of four organic dyes like rhodamine B(RhB),methyl orange(MO),congo red(CR),and methylene blue(MB)under visible light irradiation were investigated.The effects of different pH(pH=2,3,4,6,8),small organic acids(citric acid,tartaric acid,and oxalic acid),and foreign ions(ions in tap water and surface water)on Cr(VI)reduction were explored.The results revealed that the UAC-100 heterojunctions displayed more remarkable Cr(VI)reduction performance than the pristine UiO-66-NH2 and Ag2CO3,resulting from the improved separation of photo-induced electrons and holes.The enhanced photocatalytic activity of UAC-100 was further confirmed by the photoluminescence measurement,electrochemical analysis,and active species trapping experiments.After four cycles’experiments,the photocatalytic Cr(VI)reduction efficiency over UAC-100 was still over 99%,which exhibited that UAC-100 had excellent reusability and stability.Finally,the corresponding photocatalytic reaction mechanism was proposed and tested.展开更多
It was observed that the p-aminobenzoic acid(PABA)molecules adsorbed on A92CO3 colloids exhibited strong SERS effect,the enhancement factor is estimated at 10~7—10~8 The mechanism of SERS effect on PABA adsorbed on t...It was observed that the p-aminobenzoic acid(PABA)molecules adsorbed on A92CO3 colloids exhibited strong SERS effect,the enhancement factor is estimated at 10~7—10~8 The mechanism of SERS effect on PABA adsorbed on the colloids was discussed.展开更多
A series of novel AgCl/AgaCO3 heterostructured photocatalysts with different AgCl contents （5 wt%, 10 wt%, 20 wt%, and 30 wt%） were prepared by facile coprecipitation method at room temperature. The resulting produc...A series of novel AgCl/AgaCO3 heterostructured photocatalysts with different AgCl contents （5 wt%, 10 wt%, 20 wt%, and 30 wt%） were prepared by facile coprecipitation method at room temperature. The resulting products were characterized by powder X-ray diffraction （XRD）, scanning electron microscopy （SEM）, X-ray photoelectron spectroscopy （XPS）, and ultraviolet-visible diffuse reflectance spectroscopy （UV-Vis DRS）, respectively. The photocatalytic activity of the samples was evaluated by photocatalytic degradation of methyl orange （MO） under UV light irradiation. With the optimal AgCl content of 20 wt%, the AgCl/AgECO3 composite exhibits the greatest enhancement in photocatalytic degradation efficiency. Its first-order reaction rate constant （0.67 h^-1） is 5.2 times faster than that of Ag2CO3 （0.13 h^-1）, and 16.8 times faster than that of AgCl （0.04 h^-1）. The formation of AgCl/AgaCO3 heterostructure could effectively suppress the recombination of the photo-generated electron and hole, resulting in an increase in photocatalytic activity.展开更多
A series of N‐CQDs/Ag2CO3composite crystals(where N‐CQDs=Nitrogen doped carbon quantumdots)were prepared by adding different volumes of a solution of N‐CQDs during Ag2CO3crystalgrowth.Under irradiation from a350‐W...A series of N‐CQDs/Ag2CO3composite crystals(where N‐CQDs=Nitrogen doped carbon quantumdots)were prepared by adding different volumes of a solution of N‐CQDs during Ag2CO3crystalgrowth.Under irradiation from a350‐W Xe lamp light(with optical filter,λ≥420nm),the performanceof N‐CQDs/Ag2CO3in photocatalytic degradation of phenol was evaluated.The as‐preparedsamples were analyzed by XRD,SEM,TEM,BET,element mapping,UV‐vis DRS,FT‐IR,XPS,transientphotocurrent response and EIS testing.The results showed that after coupling with trace amountsof N‐CQDs,both the photocatalytic activity and stability of Ag2CO3were greatly boosted.The additionof N‐CQDs solution influenced the crystallization of Ag2CO3,resulting in a distinct decrease inAg2CO3crystal size and an obvious increase in surface area.Moreover,the charge transfer resistancewas greatly reduced,and the separation efficiency of photogenerated electrons and holes wasstrongly promoted.The presence of NCQDs on the surface of the catalysts facilitates the transfer ofphotogenerated electrons,slowing the photocorrosion rate of Ag2CO3,and then resulting in higherstability than bare Ag2CO3in degradation.The synergistic effect of the improvement of morphologyand charge transfer rate thus accounted for the superior photocatalytic performance ofN‐CQDs/Ag2CO3.展开更多
基金supported by the National Natural Science Foundation of China(51878023,51578034)Great Wall Scholars Training Program Project of Beijing Municipality Universities(CIT&TCD20180323)+2 种基金Project of Construction of Innovation Teams and Teacher Career Development for Universities and Colleges Under Beijing Municipality(IDHT20170508)Beijing Talent Project(2018A35)BUCEA Post Graduate Innovation Project(PG2019039)~~
文摘A series of UiO-66-NH2/Ag2CO3 Z-scheme heterojunctions were prepared by a simple ion-exchange-solution method using UiO-66-NH2 and semiconductor Ag2CO3 as precursors.The photocatalytic activities of UAC-X(UAC-20,50,100,150,200)Z-scheme heterojunctions toward the hexavalent chromium(Cr(VI))reduction and UAC-100 toward oxidative degradation of four organic dyes like rhodamine B(RhB),methyl orange(MO),congo red(CR),and methylene blue(MB)under visible light irradiation were investigated.The effects of different pH(pH=2,3,4,6,8),small organic acids(citric acid,tartaric acid,and oxalic acid),and foreign ions(ions in tap water and surface water)on Cr(VI)reduction were explored.The results revealed that the UAC-100 heterojunctions displayed more remarkable Cr(VI)reduction performance than the pristine UiO-66-NH2 and Ag2CO3,resulting from the improved separation of photo-induced electrons and holes.The enhanced photocatalytic activity of UAC-100 was further confirmed by the photoluminescence measurement,electrochemical analysis,and active species trapping experiments.After four cycles’experiments,the photocatalytic Cr(VI)reduction efficiency over UAC-100 was still over 99%,which exhibited that UAC-100 had excellent reusability and stability.Finally,the corresponding photocatalytic reaction mechanism was proposed and tested.
文摘It was observed that the p-aminobenzoic acid(PABA)molecules adsorbed on A92CO3 colloids exhibited strong SERS effect,the enhancement factor is estimated at 10~7—10~8 The mechanism of SERS effect on PABA adsorbed on the colloids was discussed.
基金National Natural Science Foundation of China(51572076,51508172,51378183)Science and Technology Bureau of Xiangyang,and the Foundation of Hubei Key Laboratory of Low Dimensional Optoelectronic Materials and Devices(14XKL1002)
基金financially supported by the National Natural Science Foundation of China(Nos.21067004 and21263005)the Young Science and Technology Project of Jiangxi Province Natural Science Foundation(No.20133BAB21003)+1 种基金the Young Scientist Training Project of Jiangxi Province(No.20122BCB23015)the Science and Technology Landing Project of Jiangxi Province Education Office(No.KJLD14046)
文摘A series of novel AgCl/AgaCO3 heterostructured photocatalysts with different AgCl contents （5 wt%, 10 wt%, 20 wt%, and 30 wt%） were prepared by facile coprecipitation method at room temperature. The resulting products were characterized by powder X-ray diffraction （XRD）, scanning electron microscopy （SEM）, X-ray photoelectron spectroscopy （XPS）, and ultraviolet-visible diffuse reflectance spectroscopy （UV-Vis DRS）, respectively. The photocatalytic activity of the samples was evaluated by photocatalytic degradation of methyl orange （MO） under UV light irradiation. With the optimal AgCl content of 20 wt%, the AgCl/AgECO3 composite exhibits the greatest enhancement in photocatalytic degradation efficiency. Its first-order reaction rate constant （0.67 h^-1） is 5.2 times faster than that of Ag2CO3 （0.13 h^-1）, and 16.8 times faster than that of AgCl （0.04 h^-1）. The formation of AgCl/AgaCO3 heterostructure could effectively suppress the recombination of the photo-generated electron and hole, resulting in an increase in photocatalytic activity.
基金supported by the National Natural Science Foundation of China(21567008,21607064,21707055)Program of Qingjiang Excellent Young Talents,Jiangxi University of Science and Technology+2 种基金Program of 5511 Talents in Scientific and Technological Innovation of Jiangxi Province(20165BCB18014)Academic and Technical Leaders of the Main Disciplines in Jiangxi Province(20172BCB22018)Jiangxi Province Natural Science Foundation(20161BAB203090)~~
文摘A series of N‐CQDs/Ag2CO3composite crystals(where N‐CQDs=Nitrogen doped carbon quantumdots)were prepared by adding different volumes of a solution of N‐CQDs during Ag2CO3crystalgrowth.Under irradiation from a350‐W Xe lamp light(with optical filter,λ≥420nm),the performanceof N‐CQDs/Ag2CO3in photocatalytic degradation of phenol was evaluated.The as‐preparedsamples were analyzed by XRD,SEM,TEM,BET,element mapping,UV‐vis DRS,FT‐IR,XPS,transientphotocurrent response and EIS testing.The results showed that after coupling with trace amountsof N‐CQDs,both the photocatalytic activity and stability of Ag2CO3were greatly boosted.The additionof N‐CQDs solution influenced the crystallization of Ag2CO3,resulting in a distinct decrease inAg2CO3crystal size and an obvious increase in surface area.Moreover,the charge transfer resistancewas greatly reduced,and the separation efficiency of photogenerated electrons and holes wasstrongly promoted.The presence of NCQDs on the surface of the catalysts facilitates the transfer ofphotogenerated electrons,slowing the photocorrosion rate of Ag2CO3,and then resulting in higherstability than bare Ag2CO3in degradation.The synergistic effect of the improvement of morphologyand charge transfer rate thus accounted for the superior photocatalytic performance ofN‐CQDs/Ag2CO3.
