Octahedral Mn_(3)O_(4)nanoparticles with an Ag-doping and nanoporous Ag(NPS)framework was simply fabricated through an alloying-etching engineering.The dual-modified Mn_(3)O_(4)(denoted as Ag−Mn_(3)O_(4)/NPS)consists ...Octahedral Mn_(3)O_(4)nanoparticles with an Ag-doping and nanoporous Ag(NPS)framework was simply fabricated through an alloying-etching engineering.The dual-modified Mn_(3)O_(4)(denoted as Ag−Mn_(3)O_(4)/NPS)consists of Ag-doped Mn_(3)O_(4)nanoparticles crosslinked with three dimensional nanoporous Ag framework.The incorporated Ag dopant is effective in improving the intrinsic ionic and electronic conductivities of Mn_(3)O_(4),while the NPS framework is introduced to improve the electron/mass transfer across the entire electrode.Profiting from the dual-modification strategy,the Ag−Mn_(3)O_(4)/NPS exhibits admirable rate capability and cycling stability.A high reversible capacity of 88.7 mA·h/g can still be retained for over 1000 cycles at a current density of 1 A/g.Moreover,a series of ex-situ experimental techniques indicate that for Ag−Mn_(3)O_(4)/NPS electrode during the zinc ion storage,Mn_(3)O_(4)is electrochemically oxidized into various MnOx(e.g.,Mn_(2)O_(3),MnO2)species in the initial charging,and the subsequent battery reaction is actually the intercalation/deintercalation of H+and Zn2+into MnOx.展开更多
Valonia tannin （VT） was gelated through polymerization with formaldehyde to prepare an adsorbent, which was found effective to remove Ag＋ from aqueous solution. The adsorption-desorption behaviors of valonia tannin...Valonia tannin （VT） was gelated through polymerization with formaldehyde to prepare an adsorbent, which was found effective to remove Ag＋ from aqueous solution. The adsorption-desorption behaviors of valonia tannin resin （VTR） were investigated under various initial Ag＋ concentrations, solution temperatures, pH values etc. The applicability of empirical kinetic models was also studied. The pseudo-second-order model studies revealed the Ag＋ sorption was very rapid. VT and VTR were characterized using FTIR and SEM before and after adsorption. The Ag＋ biosorption on VTR increased with a rise in initial concentration of Ag＋ and with a decrease in temperature. Desorption experiments were conducted at low pH values and the solutions of H2SO4, HNO3 and HCl were used for desorption. The VTR shows high adsorption capacity to Ag＋ in a wide pH range of 2.0-7.0, and a maximum adsorption capacity of 97.08 mg/g was obtained at pH 5.0 and 296 K when the initial concentration of Ag＋ was 100.0 mg/L. Ag＋ ion desorption could reach 99.6% using 1 mol/L HCl＋1% thiourea （NH2CSNH2） solution. By utilizing such characteristics of VTR, it is expected that it can be applied to recovering Ag＋ efficiently and simply with low cost.展开更多
Silver (I) was removed from aqueous environment by aloe vera shell ash supported Ni0.5Zn0.5Fe2O4 magnetic nanoparticles.The adsorbent was characterized by several methods including X-ray diffraction (XRD), scanning el...Silver (I) was removed from aqueous environment by aloe vera shell ash supported Ni0.5Zn0.5Fe2O4 magnetic nanoparticles.The adsorbent was characterized by several methods including X-ray diffraction (XRD), scanning electron microscopy (SEM), BETisotherm, vibrating sample magnetometer (VSM) and Fourier transform infrared spectroscopy (FT-IR). To determine the absorptionof silver (I) by this adsorbent, different pH values (2?7), adsorbent dose (0.01?0.5 g), concentrations of Ag+ (50, 100, 200, 300, 500,700 and 1000 mg/L) and exposure time (5?100 min) were experimented. The highest removal efficiency of Ag+ was achieved underoptimum condition (30 min and pH=5). The optimum adsorbent dose was 0.20 g (in 50 mL of 100 mg/L Ag+ solution), whichachieved a removal efficiency of 98.3%. The maximum monolayer adsorption capacity based on the Langmuir isotherm is243.90 mg/g. Characterization results revealed that specific surface area and porous volume were 814.23 m2/g and 0.726 cm3/g,respectively. The experimental data were fitted well with the Langmuir and Freundlich isotherm models. Synthesized adsorbent has desired surface area and adsorptive capacity for silver (I) adsorption in aquatic environment.展开更多
A novel plasmonic photo‐Fenton catalyst of Ag/AgCl/Fe‐S was synthesized by ion exchange and photoreduction methods.The obtained catalyst was characterized by X‐ray diffraction,X‐ray photoelectron spectroscopy,scan...A novel plasmonic photo‐Fenton catalyst of Ag/AgCl/Fe‐S was synthesized by ion exchange and photoreduction methods.The obtained catalyst was characterized by X‐ray diffraction,X‐ray photoelectron spectroscopy,scanning electron microscope imaging,and Brunauer‐Emmett‐Teller measurements.Moreover,the photocatalytic activity of Ag/AgCl/Fe‐S was investigated for its degradation activity towards bisphenol A(BPA)as target pollutant under visible light irradiation.The effects of H2O2concentration,pH value,illumination intensity,and catalyst dosage on BPA degradation were examined.Our results indicated that the Ag/AgCl material was successfully loaded onto Fe‐sepiolite and showed a high photocatalytic activity under illumination by visible light.Furthermore,active species capture experiments were performed to explore the photocatalytic mechanism of the Ag/AgCl/Fe‐S in this heterogeneous photo‐Fenton process,where the major active species included hydroxyl radicals(?OH)and holes(h+).展开更多
In recent years, the preservation of fruits and vegetables in cold storage has become an issue of increasing concern, ethylene plays a leading role among them. We found ZnO has the effect of degrading gaseous ethylene...In recent years, the preservation of fruits and vegetables in cold storage has become an issue of increasing concern, ethylene plays a leading role among them. We found ZnO has the effect of degrading gaseous ethylene, however its effect is not particularly satisfactory. Therefore, we used simple photo-deposition procedure and low-temperature calcination method to synthesize Au, Ag, and Au Ag alloy supported ZnO to improve the photocatalytic efficiency. Satisfactorily, after ZnO loaded with sole Au or Ag particles, the efficiency of ethylene degradation was 17.5 and 26.8 times than that of pure ZnO, showing a large increase in photocatalytic activity. However, the photocatalytic stability of Ag/ZnO was very poor, because Ag can be easily photooxidized to Ag2O. Surprisingly, when ZnO was successfully loaded with the Au Ag alloy, not only the photocatalytic activity was further improved to 94.8 times than that of pure ZnO, but also the photocatalytic stability was very good after 10 times of cycles. Characterization results explained that the Au-Ag alloy NPs modified ZnO showed great visible-light absorption because of the surface plasmon resonance(SPR) effect. Meanwhile, the higher photocurrent density showed the effective carrier separation ability in Au Ag/ZnO. Therefore, the cooperative action of plasmonic Au Ag bimetallic alloy NPs and efficient carrier separation capability result in the outstanding photoactivity of ethylene oxidation. At the same time, the formation of the alloy produced a new crystal structure different from Au and Ag, which overcomes the problem of poor stability of Ag/ZnO, and finally obtains Au Ag/ZnO photocatalyst with high activity and high stability. This work proposes a new concept of using metal alloys to remove ethylene in actual production.展开更多
Ag nanoparticles were fabricated on Si substrates by radio-frequency magnetron sputtering and thermal annealing treatments.It was found that Ag nanoparticles are ellipsoid at low annealing temperature,but the axis rat...Ag nanoparticles were fabricated on Si substrates by radio-frequency magnetron sputtering and thermal annealing treatments.It was found that Ag nanoparticles are ellipsoid at low annealing temperature,but the axis ratio decreases with the increase of annealing temperature,and a shape transformation from ellipsoid to sphere occurs when the temperature increases to a critical point.The experimental results showed that the surface plasmon resonances depend greatly on the nanoparticles'shape and size,which is in accordance with the theoretical calculation based on discrete dipole approximation.The results of forward-scattering efficiency(FSE) and light trapping spectrum(LTS) showed that Ag nanoparticles annealed at 400°C could strongly enhance the light harvest than those annealed at 300 and 500°C,and that the LTS peak intensity of the former is 1.7 and 1.5 times stronger than those of the later two samples,respectively.The conclusions obtained in this paper showed that Ag ellipsoid nanoparticles with appropriate size is more favorable for enhancing the light trapping.展开更多
We report the plasmon-enhanced polymer bulk-heterojunction solar cells with Ag nanoparticles (AgNPs) obtained via chemical method. Here, the AgNPs films with different particle densities are introduced between the pol...We report the plasmon-enhanced polymer bulk-heterojunction solar cells with Ag nanoparticles (AgNPs) obtained via chemical method. Here, the AgNPs films with different particle densities are introduced between the poly (3,4-ethylene dioxythiophene) poly (styrenesulfonate) (PEDOT: PSS) buffer layer and the poly (3-hexythiophene):[6,6]-phenyl-c61 butyric acid methyl ester (P3HT: PCBM) layer. By improving the optical absorption of the active layer owing to the localized surface plasmons, the power conversion efficiency of the solar cells is increased compared with the control device. It is shown that the efficiency of the device increases with the density of AgNPs. For the device employing higher density, the resulted power conversion efficiency is found to increase from 2.89% to 3.38%, enhanced by 16.96%.展开更多
Silver nanoparticles(Ag NPs)are synthesized with chemical method,which are introduced into the traditional organic photovoltaic(OPV)structure.The experimental results show that both the optical and photoelectric prope...Silver nanoparticles(Ag NPs)are synthesized with chemical method,which are introduced into the traditional organic photovoltaic(OPV)structure.The experimental results show that both the optical and photoelectric properties are en-hanced because of localized surface plasmon(LSP)effects of Ag NPs.The advantage of adding Ag NPs behind active layer in incident direction is discussed.We believe this route can avoid absorption shadow and enhance the reusing of transmitted light of active layer.The average short-circuit current(J SC)of the optimum device can be raised from 9.23mA/cm2 to 10.84mA/cm2,and the energy converting efficiency(PCE)can be raised from 3.22% to 3.85%.展开更多
基金financially supported by the Natural Science Foundation of Shandong Province,China (Nos.ZR2023ME155,ZR2023ME085)the National Natural Science Foundation of China (No.52201254)+1 种基金the Project of“20 Items of University”of Jinan,China (No.202228046)the Taishan Scholar Project of Shandong Province,China (No.tsqn202306226)。
文摘Octahedral Mn_(3)O_(4)nanoparticles with an Ag-doping and nanoporous Ag(NPS)framework was simply fabricated through an alloying-etching engineering.The dual-modified Mn_(3)O_(4)(denoted as Ag−Mn_(3)O_(4)/NPS)consists of Ag-doped Mn_(3)O_(4)nanoparticles crosslinked with three dimensional nanoporous Ag framework.The incorporated Ag dopant is effective in improving the intrinsic ionic and electronic conductivities of Mn_(3)O_(4),while the NPS framework is introduced to improve the electron/mass transfer across the entire electrode.Profiting from the dual-modification strategy,the Ag−Mn_(3)O_(4)/NPS exhibits admirable rate capability and cycling stability.A high reversible capacity of 88.7 mA·h/g can still be retained for over 1000 cycles at a current density of 1 A/g.Moreover,a series of ex-situ experimental techniques indicate that for Ag−Mn_(3)O_(4)/NPS electrode during the zinc ion storage,Mn_(3)O_(4)is electrochemically oxidized into various MnOx(e.g.,Mn_(2)O_(3),MnO2)species in the initial charging,and the subsequent battery reaction is actually the intercalation/deintercalation of H+and Zn2+into MnOx.
基金supported by The Scientific and Technological Research Council of Turkey. The authors would like to present their deepest thanks TUBITAK for its financial support
文摘Valonia tannin （VT） was gelated through polymerization with formaldehyde to prepare an adsorbent, which was found effective to remove Ag＋ from aqueous solution. The adsorption-desorption behaviors of valonia tannin resin （VTR） were investigated under various initial Ag＋ concentrations, solution temperatures, pH values etc. The applicability of empirical kinetic models was also studied. The pseudo-second-order model studies revealed the Ag＋ sorption was very rapid. VT and VTR were characterized using FTIR and SEM before and after adsorption. The Ag＋ biosorption on VTR increased with a rise in initial concentration of Ag＋ and with a decrease in temperature. Desorption experiments were conducted at low pH values and the solutions of H2SO4, HNO3 and HCl were used for desorption. The VTR shows high adsorption capacity to Ag＋ in a wide pH range of 2.0-7.0, and a maximum adsorption capacity of 97.08 mg/g was obtained at pH 5.0 and 296 K when the initial concentration of Ag＋ was 100.0 mg/L. Ag＋ ion desorption could reach 99.6% using 1 mol/L HCl＋1% thiourea （NH2CSNH2） solution. By utilizing such characteristics of VTR, it is expected that it can be applied to recovering Ag＋ efficiently and simply with low cost.
基金the Islamic Azad University-Bandar Abbas Branch for financial support
文摘Silver (I) was removed from aqueous environment by aloe vera shell ash supported Ni0.5Zn0.5Fe2O4 magnetic nanoparticles.The adsorbent was characterized by several methods including X-ray diffraction (XRD), scanning electron microscopy (SEM), BETisotherm, vibrating sample magnetometer (VSM) and Fourier transform infrared spectroscopy (FT-IR). To determine the absorptionof silver (I) by this adsorbent, different pH values (2?7), adsorbent dose (0.01?0.5 g), concentrations of Ag+ (50, 100, 200, 300, 500,700 and 1000 mg/L) and exposure time (5?100 min) were experimented. The highest removal efficiency of Ag+ was achieved underoptimum condition (30 min and pH=5). The optimum adsorbent dose was 0.20 g (in 50 mL of 100 mg/L Ag+ solution), whichachieved a removal efficiency of 98.3%. The maximum monolayer adsorption capacity based on the Langmuir isotherm is243.90 mg/g. Characterization results revealed that specific surface area and porous volume were 814.23 m2/g and 0.726 cm3/g,respectively. The experimental data were fitted well with the Langmuir and Freundlich isotherm models. Synthesized adsorbent has desired surface area and adsorptive capacity for silver (I) adsorption in aquatic environment.
基金supported by the National Natural Science Foundation of China(41573118)Research Foundation of Education Bureau of Hunan Province,China(14B177)Special Project of Xiangtan University~~
文摘A novel plasmonic photo‐Fenton catalyst of Ag/AgCl/Fe‐S was synthesized by ion exchange and photoreduction methods.The obtained catalyst was characterized by X‐ray diffraction,X‐ray photoelectron spectroscopy,scanning electron microscope imaging,and Brunauer‐Emmett‐Teller measurements.Moreover,the photocatalytic activity of Ag/AgCl/Fe‐S was investigated for its degradation activity towards bisphenol A(BPA)as target pollutant under visible light irradiation.The effects of H2O2concentration,pH value,illumination intensity,and catalyst dosage on BPA degradation were examined.Our results indicated that the Ag/AgCl material was successfully loaded onto Fe‐sepiolite and showed a high photocatalytic activity under illumination by visible light.Furthermore,active species capture experiments were performed to explore the photocatalytic mechanism of the Ag/AgCl/Fe‐S in this heterogeneous photo‐Fenton process,where the major active species included hydroxyl radicals(?OH)and holes(h+).
文摘In recent years, the preservation of fruits and vegetables in cold storage has become an issue of increasing concern, ethylene plays a leading role among them. We found ZnO has the effect of degrading gaseous ethylene, however its effect is not particularly satisfactory. Therefore, we used simple photo-deposition procedure and low-temperature calcination method to synthesize Au, Ag, and Au Ag alloy supported ZnO to improve the photocatalytic efficiency. Satisfactorily, after ZnO loaded with sole Au or Ag particles, the efficiency of ethylene degradation was 17.5 and 26.8 times than that of pure ZnO, showing a large increase in photocatalytic activity. However, the photocatalytic stability of Ag/ZnO was very poor, because Ag can be easily photooxidized to Ag2O. Surprisingly, when ZnO was successfully loaded with the Au Ag alloy, not only the photocatalytic activity was further improved to 94.8 times than that of pure ZnO, but also the photocatalytic stability was very good after 10 times of cycles. Characterization results explained that the Au-Ag alloy NPs modified ZnO showed great visible-light absorption because of the surface plasmon resonance(SPR) effect. Meanwhile, the higher photocurrent density showed the effective carrier separation ability in Au Ag/ZnO. Therefore, the cooperative action of plasmonic Au Ag bimetallic alloy NPs and efficient carrier separation capability result in the outstanding photoactivity of ethylene oxidation. At the same time, the formation of the alloy produced a new crystal structure different from Au and Ag, which overcomes the problem of poor stability of Ag/ZnO, and finally obtains Au Ag/ZnO photocatalyst with high activity and high stability. This work proposes a new concept of using metal alloys to remove ethylene in actual production.
基金supported by the National Natural Science Foundation of China (Grant Nos. 61006050 and 51072051)the Natural Science Foundation of Beijing,China (Grant No. 2102042)+2 种基金the Fundamental Research Funds for the Central Universities (Grant No. 10QG24)the National High Technology Research and Development Program ("863" Project)(Grant No. 2011AA050507)the National Basic Research Program of China("973" Project)(Grant No. 2010CB93380)
文摘Ag nanoparticles were fabricated on Si substrates by radio-frequency magnetron sputtering and thermal annealing treatments.It was found that Ag nanoparticles are ellipsoid at low annealing temperature,but the axis ratio decreases with the increase of annealing temperature,and a shape transformation from ellipsoid to sphere occurs when the temperature increases to a critical point.The experimental results showed that the surface plasmon resonances depend greatly on the nanoparticles'shape and size,which is in accordance with the theoretical calculation based on discrete dipole approximation.The results of forward-scattering efficiency(FSE) and light trapping spectrum(LTS) showed that Ag nanoparticles annealed at 400°C could strongly enhance the light harvest than those annealed at 300 and 500°C,and that the LTS peak intensity of the former is 1.7 and 1.5 times stronger than those of the later two samples,respectively.The conclusions obtained in this paper showed that Ag ellipsoid nanoparticles with appropriate size is more favorable for enhancing the light trapping.
基金supported by the Project of Tianjin Ministry of Education (No. 20100723)the National Natural Science Foundation of China (No. 60876046)
文摘We report the plasmon-enhanced polymer bulk-heterojunction solar cells with Ag nanoparticles (AgNPs) obtained via chemical method. Here, the AgNPs films with different particle densities are introduced between the poly (3,4-ethylene dioxythiophene) poly (styrenesulfonate) (PEDOT: PSS) buffer layer and the poly (3-hexythiophene):[6,6]-phenyl-c61 butyric acid methyl ester (P3HT: PCBM) layer. By improving the optical absorption of the active layer owing to the localized surface plasmons, the power conversion efficiency of the solar cells is increased compared with the control device. It is shown that the efficiency of the device increases with the density of AgNPs. For the device employing higher density, the resulted power conversion efficiency is found to increase from 2.89% to 3.38%, enhanced by 16.96%.
基金supported by the National Natural Science Foundation of China(Nos.60876046and60976048)the Tianjin Natural Science Foundation(Nos.10ZCKFGX01900,10SYSYJC28100and12JCQNJC01300)+1 种基金the Scientific Developing Foundation of Tianjin Education Commission(No.20100723)the Tianjin Key Discipline of Material Physics and Chemistry
文摘Silver nanoparticles(Ag NPs)are synthesized with chemical method,which are introduced into the traditional organic photovoltaic(OPV)structure.The experimental results show that both the optical and photoelectric properties are en-hanced because of localized surface plasmon(LSP)effects of Ag NPs.The advantage of adding Ag NPs behind active layer in incident direction is discussed.We believe this route can avoid absorption shadow and enhance the reusing of transmitted light of active layer.The average short-circuit current(J SC)of the optimum device can be raised from 9.23mA/cm2 to 10.84mA/cm2,and the energy converting efficiency(PCE)can be raised from 3.22% to 3.85%.
