Antimony-doped tin hydroxide colloid precipitates have been synthesized by hydrolysis of SnCl4 and SbCl3 using: (1) an ion-exchange hydrolysis to remove chlorine ions, and (2) isoamyl acetate as an azeotropic sol...Antimony-doped tin hydroxide colloid precipitates have been synthesized by hydrolysis of SnCl4 and SbCl3 using: (1) an ion-exchange hydrolysis to remove chlorine ions, and (2) isoamyl acetate as an azeotropic solvent to obviate water. The obtained dried powder is of high dispersivity without any need for further grinding. The size and dispersivity of the final particles are investigated with the aid of TG-DTA, BET, XRD and TEM. After having calcined, the antimony-doped tin oxide nanopowder possesses a tetragonal rutile structure with high dispersivity, uniform particles and low hard agglomeration.展开更多
Antimony-doped tin hydroxide colloid precipitates were prepared by hydrolysis of SnCl4·5H2O and SbCl3 ethanol solutions. Isoamyl acetate was selected as azeotropic drying solvent and was compared with the most co...Antimony-doped tin hydroxide colloid precipitates were prepared by hydrolysis of SnCl4·5H2O and SbCl3 ethanol solutions. Isoamyl acetate was selected as azeotropic drying solvent and was compared with the most commonly used n-butanol solvent on treating precipitate for low hard agglomeration precursor powders. The FT-IR, BET, XRD, and TEM results of the precursor powders and calcinated antimony-doped tin oxide powders were recorded. The results demonstrate that isoamyl acetate is an excellent azeotropic drying solvent that can effectively prevent the agglomeration of particles and greatly improve the fluffiness of the obtained dried powders. After these precursor powders are calcined, antimony-doped tin oxide nanopowders with tetragonal rutile structure and high dispersivity can be obtained.展开更多
In this paper, conductive antimony-doped tin oxide (ATO) composite particles is prepared by hydroxylation method of metal alcoxides. This method has many advantages such as little pollution, low-cost, simple sheet and...In this paper, conductive antimony-doped tin oxide (ATO) composite particles is prepared by hydroxylation method of metal alcoxides. This method has many advantages such as little pollution, low-cost, simple sheet and equipment. The synthesis processing and the ATO nanoparticles are characterized by means of transmission electron microscope (TEM), X-ray diffraction (XRD), thermal gravimetric and differential thermal analysis, and BET. The results show that the ATO nanoparticles is tetragonal rutile crystal structure. TEM show that the particles are monodispersed with weak aggromation. The size of the particles calcinated at 700 is about 8nm. The specific areas are 153 m^2·g~ -1 . In addition to, ATO nanoparticles have good electric展开更多
Proton exchange membrane(PEM)water electrolysis represents a promising technology for green hydrogen production,but its widespread deployment is greatly hindered by the indispensable usage of platinum group metal cata...Proton exchange membrane(PEM)water electrolysis represents a promising technology for green hydrogen production,but its widespread deployment is greatly hindered by the indispensable usage of platinum group metal catalysts,especially iridium(Ir)based materials for the energy-demanding oxygen evolution reaction(OER).Herein,we report a new sequential precipitation approach to the synthesis of mixed Ir-nickel(Ni)oxy-hydroxide supported on antimony-doped tin oxide(ATO)nanoparticles(IrNiyO_(x)/ATO,20 wt.%(Ir+Ni),y=0,1,2,and 3),aiming to reduce the utilisation of scarce and precious Ir while maintaining its good acidic OER performance.When tested in strongly acidic electrolyte(0.1 M HClO_(4)),the optimised IrNi1Ox/ATO shows a mass activity of 1.0 mAµgIr^(−1) and a large turnover frequency of 123 s^(−1) at an overpotential of 350 mV,as well as a comparatively small Tafel slope of 50 mV dec^(−1),better than the IrOx/ATO control,particularly with a markedly reduced Ir loading of only 19.7µgIr cm^(−2).Importantly,IrNi1O_(x)/ATO also exhibits substantially better catalytic stability than other reference catalysts,able to continuously catalyse acidic OER at 10 mA cm^(−2) for 15 h without obvious degradation.Our in-situ synchrotron-based x-ray absorption spectroscopy confirmed that the Ir^(3+)/Ir^(4+)species are the active sites for the acidic OER.Furthermore,the performance of IrNi1Ox/ATO was also preliminarily evaluated in a membrane electrode assembly,which shows better activity and stability than other reference catalysts.The IrNi1Ox/ATO reported in this work is a promising alternative to commercial IrO_(2) based catalysts for PEM electrolysis.展开更多
Antimony-doped tin oxide(ATO) nanoparticles with an average size of ~ 6 nm were prepared by co-precipitation and subsequent heat treatment. Graphitic carbon nitride(g-CN)/ATO hybrid nanocomposite was designed by the ...Antimony-doped tin oxide(ATO) nanoparticles with an average size of ~ 6 nm were prepared by co-precipitation and subsequent heat treatment. Graphitic carbon nitride(g-CN)/ATO hybrid nanocomposite was designed by the combination of thermally synthesized g-CN and ATO nanoparticles by ultrasonication. The materials were characterized using N2 adsorption/desorption(BET), X-ray diffraction(XRD), scanning electron microscopy(SEM), energy dispersive spectroscopy(EDS), transmission electron microscopy(TEM) and Fourier transform infrared spectroscopy(FTIR). A mixture of five volatile organic compounds(VOCs, chloroform, benzene, toluene, xylene and styrene) was used to compare the adsorption capacity of the samples. The adsorption capacity of ATO nanoparticles was improved by the addition of g-CN. Experimental data showed that, among the five VOCs,chloroform was the least adsorbed, regardless of the samples. The g-CN/ATO showed nearly three times greater adsorption capacity for the VOC mixture than pure ATO. The unchanged efficiency of VOC adsorption during cyclic use demonstrated the completely reversible adsorption and desorption behavior of the nanocomposite at room conditions. This economically and environmentally friendly material can be a practical solution for outdoor and indoor VOC removal.展开更多
Tin oxide nanociystals with diameters smaller than 10 nm were synthesized using Na2SnO3 and CO2 as reactants and cetyltrimethylammonium bromide(CTAB) as stabilizer under mild conditions.As a mild acidic gas,CO2 is f...Tin oxide nanociystals with diameters smaller than 10 nm were synthesized using Na2SnO3 and CO2 as reactants and cetyltrimethylammonium bromide(CTAB) as stabilizer under mild conditions.As a mild acidic gas,CO2 is favorable for the accurate adjustment of pH value of Na2SnO3 solution.Stannate salt is stable,cheap and easy in operation.The effects of Na2SnO3concentration,CTAB concentration,aging temperature,and aging time on the nanociystals were studied.It was found that,with the increasing Na2SnO3 concentration,aging temperature and aging time,SnO2 nanociystals size decreases.The formation of SnO2nanociystals can be interpreted by electrostatic-interaction mechanism.SnO2 nanociystals show high photocatalytic activities in the degradation of Rhodamine B solution.The catalytic activity of small nanocrystals is higher than that of large ones.展开更多
Flower-like tin oxide-supported platinum(Pt/SnOx) with a hierarchical structure was synthesized by a hydrothermal method and characterized by XRD,SEM,TEM,high resolution TEM,XPS and nitrogen adsorption.The flower-li...Flower-like tin oxide-supported platinum(Pt/SnOx) with a hierarchical structure was synthesized by a hydrothermal method and characterized by XRD,SEM,TEM,high resolution TEM,XPS and nitrogen adsorption.The flower-like Pt/SnOx microspheres of 1 μm in diameter were composed of staggered petal-like nanosheets with a thickness of 20 nm.Pt nanoparticles(NPs) of 2-3 nm were well dispersed on the SnOx nanosheets.The catalyst was tested in the catalytic oxidation of gaseous formaldehyde(HCHO) at room temperature,and exhibited enhanced activity compared to Pt NPs supported on commercial SnO and ground SnOx.HCHO removal of 87%was achieved over the hierarchical Pt/SnOx after 1 h of reaction,which was 1.5 times that over the ground SnOx-supported Pt(Pt/g-SnOx),and the high activity was maintained after six recycles,showing the high stability of this catalyst.HCHO decomposition kinetics was modeled as a second order reaction.The reaction rate constant for Pt/SnOx was 5.6 times higher than Pt/g-SnOx.The hierarchical pore structure was beneficial for the diffusion and adsorption of HCHO molecules,and the highly dispersed Pt NPs on the SnOx nanosheets were the active sites for the oxidative decomposition of HCHO into CO2 and H2O.This study provided a promising approach for designing efficient catalysts for indoor HCHO removal at ambient temperature.展开更多
The present work mainly describes the technology for preparing indium-tin oxide (ITO) targets by cold isostatic pressing (CIP) and normal pressure sintering process. ITO powders were produced by chemical co-precip...The present work mainly describes the technology for preparing indium-tin oxide (ITO) targets by cold isostatic pressing (CIP) and normal pressure sintering process. ITO powders were produced by chemical co-precipitation and shaped into an ITO green compact with a relative density of 60% by CIP under 300 MPa. Then, an ITO target with a relative density larger than 99.6% was obtained by sintering this green compact at 1550℃ for 8 h. The effects of forming pressure, sintering temperature and sintering time on the density of the target were inves- tigated. Also, a discussion was made on the sintering atmosphere.展开更多
Nanostructured gold catalyst supported on metal oxide is highly active for the CO oxidation reac‐tion. In this work, a new type of oxide support, zinc tin oxide, has been used to deposit 0.7 wt%Au via a deposition‐p...Nanostructured gold catalyst supported on metal oxide is highly active for the CO oxidation reac‐tion. In this work, a new type of oxide support, zinc tin oxide, has been used to deposit 0.7 wt%Au via a deposition‐precipitation method. The textural properties of Zn2SnO4 support have been tuned by varying the molar ratio between base (N2H4·H2O) and metal ion (Zn2+) to be 4/1, 8/1 and 16/1. The catalytic tests for CO oxidation reaction revealed that the reactivity on Au‐Zn2SnO4 with N2H4·H2O/Zn2+ = 8/1 was the highest, while the reactivity on Au‐Zn2SnO4 with N2H4·H2O/Zn2+ =16/1 was almost identical to that of the pure support. Both fresh and used catalysts have been characterized by multiple techniques including nitrogen adsorption‐desorption, X‐ray diffraction, transmission electron microscopy, high‐angle annular dark‐field scanning transmission electron microscopy, X‐ray photoelectron spectroscopy, X‐ray adsorption fine structure, and tempera‐ture‐programmed reduction by hydrogen. These demonstrated that the textural properties, espe‐cially pore volume and pore size distribution, of Zn2SnO4 play crucial roles in the averaged size of gold nanoparticles, and thus determine the catalytic activity of Au‐Zn2SnO4 for CO oxidation.展开更多
Tin/tin oxide materials are key electrocatalysts for selective conversion of CO;to formate/formic acid.Herein we report a tin oxide material with nitrogen doping by using ammonia treatment at elevated temperature. The...Tin/tin oxide materials are key electrocatalysts for selective conversion of CO;to formate/formic acid.Herein we report a tin oxide material with nitrogen doping by using ammonia treatment at elevated temperature. The N doped material demonstrated enhanced electrocatalytic CO;reduction activity, showing high Faradaic efficiency(90%) for formate at -0.65 V vs. RHE with partial current density of 4 mA/cm;.The catalysis was contributed to increased electron negativity of N atom compared to O atom. Additionally, the N-doped catalyst demonstrates sulfur tolerance with retained formate selectivity. The analysis after electrolysis shows that the catalyst structure partially converts to metallic Sn, and thus the combined Sn/N-SnO;is the key for the active CO;catalysis.展开更多
Silver tin oxide composite powders were synthesized by the hydrothermal method with a silver ammine solution and a Na2SnO3 solution as raw materials. H2C2O4 was used as the co-precipitator of silver ions and tin ions....Silver tin oxide composite powders were synthesized by the hydrothermal method with a silver ammine solution and a Na2SnO3 solution as raw materials. H2C2O4 was used as the co-precipitator of silver ions and tin ions. The co-precipitation conditions were investigated. The results show that the co-precipitate of Ag2C2O4 and Sn(OH)4 is available when the pH value of the solution is 4.27-8.36. Using the obtained precipitate as precursor,the reduction of Ag+ and the crystallization of tin oxide were carried out simultaneously by the hydrothermal method and silver tin oxide composite powders were obtained. The composite powders were characterized by X-ray diffraction (XRD) analysis,scanning electron microscope (SEM),and energy spectrum analysis. The results show that the silver tin oxide composite powders are small with a diameter of about 2 μm and with homogeneous distribution of tin.展开更多
A SnO-graphite composite material, which can deliver high capacities and good cycling stability compared with unsupported SnO, was described. This material prepared via chemical co-precipitation reaction in the presen...A SnO-graphite composite material, which can deliver high capacities and good cycling stability compared with unsupported SnO, was described. This material prepared via chemical co-precipitation reaction in the presence of graphite consists of high dispersion of SnO with a size of about several hundred nanometers in the graphite. The phase structure was analyzed by X-ray diffraction (XRD). The morphology and the element distribution were examined by scanning electron microscopy (SEM) equipped with energy spectrum. The results show that the SnO-graphite composites produced by slowly hydrolysis have higher rechargeable capacities than pure graphite and better cycling performance than SnO.展开更多
The emergence of hybrid organic-inorganic metal halide perovskite solar cells (PSCs) causes a break through in the solar technology recently due to its fabrication processes. The dramatic enhancenlent in in 2009 to ...The emergence of hybrid organic-inorganic metal halide perovskite solar cells (PSCs) causes a break through in the solar technology recently due to its fabrication processes. The dramatic enhancenlent in in 2009 to the recent certified record PCE of 22.7% superior optoelectronic properties and the low-cost power conversion efficiency (PCE) of PSCs flom 3.8% ndicates huge potential of PSCs for future high efficiency and large scale photovoltaic manufacturing. The electron selective layer (ESL) plays an important role in electron extraction and hole blocking function in PSCs, and there have been great interest in developing efficient ESL materials. Recently, tin oxide (SnO2) as an ESL has attracted significant research attentions owing to its low temperature preparation processes as well as yielding high PCE and good stability of PSCs. In this perspective article, we focus on the development progress of SnO2 as an ESL m PSCs, and discuss the strategies for preparing SnO2 to achieve PSCs with high efficiency, less hysteresis and good device stability.展开更多
Annealing effect on the performance of fully transparent thin-film transistor (TTFT), in which zinc tin oxide (ZnSnO) is used as the channel material and SiO2 as the gate insulator, is investigated. The ZnSnO acti...Annealing effect on the performance of fully transparent thin-film transistor (TTFT), in which zinc tin oxide (ZnSnO) is used as the channel material and SiO2 as the gate insulator, is investigated. The ZnSnO active layer is deposited by radio frequency magnetron sputtering while a SiO2 gate insulator is formed by plasma-enhanced chemical vapor deposition. The saturation field-effect mobility and on/off ratio of the TTFT are improved by low temperature annealing in vacuum. Maximum saturation field-effect mobility and on/off ratio of 56.2 cm2/(V.s) and 3×10^5 are obtained, respectively. The transfer characteristics of the ZnSnO TPT are simulated using an analytical model and good agreement between measured and the calculated transfer characteristics is demonstrated.展开更多
Indium tin oxide(ITO)thin films(100±10nm)were deposited on PC(polycarbonate)and glass substrates by rf(radio-frequency)mannetron spuutering.The oxygen content of the ITO films was changed by variation of ...Indium tin oxide(ITO)thin films(100±10nm)were deposited on PC(polycarbonate)and glass substrates by rf(radio-frequency)mannetron spuutering.The oxygen content of the ITO films was changed by variation of the sputtering gas composition.All the other deposition parameters were kept constant.The sheet resistance.optical transmittance and microstructure of ITO films were investigated using a four-point probe.spectrophotometer,X-ray diffractometer(XRD)and atomic force microscope(AFM).Sheet resistances for the ITO films with optical transmittance more than 75% on PC substrates varied from 40Ω/cm^2 to more than 104 Ω/cm^2 with increasing oxygen partial pressure from O to about 2%.The same tendeney of sheet resistances increasing with increasing oxygen partial pressure was observed on glass substrates.The X-ray diffraction data indicated polycrystalline filns with grain orientations predominantly along(440)and (422)directions.The intensities of (440)and (422)peaks increased slightly with the increase of oxygen partial pressure both on PC and glass substrates.The AFM images show that the ITO films on PC substrates were dense and uniform.The average grain size of the films was about 40nm.展开更多
Nanostructured tin dioxide (SnO2) powders were prepared by a sol-gel dialytic process and and the doping of CuO on it was completed by a deposition-precipitation method.The thick film sensors were fabricated from th...Nanostructured tin dioxide (SnO2) powders were prepared by a sol-gel dialytic process and and the doping of CuO on it was completed by a deposition-precipitation method.The thick film sensors were fabricated from the CuO/SnO2 polycrystalline powders.Sensing behavior of the sensor was investigated with various gases including CO,H2,NH3,hexane,acetone,ethanol,methanol and H2S in air.The as-synthesized gas sensor had much better response to H2S than to other gases.At the same time,the CuO/SnO2 sensor had enough sensitivity,together with fast response and recovery,to distinguish H2S from those gases at 160 and 210 ℃.Therefore,it might have promising applications in the future.展开更多
Microbial cellulose (MC) membranes produced by Acetobacter xylinum NUST4.1,were used as flexible substrates for the fabrication of transparent indium tin oxide (ITO) electrodes.Transparent and conductive ITO thin ...Microbial cellulose (MC) membranes produced by Acetobacter xylinum NUST4.1,were used as flexible substrates for the fabrication of transparent indium tin oxide (ITO) electrodes.Transparent and conductive ITO thin films were deposited on MC membrane at room temperature using radio frequency (RF) magnetron sputtering.The optimum ITO deposition conditions were achieved by examining crystalline structure,surface morphology and op-toelectrical characteristics with X-ray diffraction (XRD),scanning electron microscopy (SEM),atomic force mi-croscopy (AFM),and UV spectroscopy.The sheet resistance of the samples was measured with a four-point probe and the resistivity of the film was calculated.The results reveal that the preferred orientation of the deposited ITO crystals is strongly dependent upon with oxygen content (O2/Ar,volume ratio) in the sputtering chamber.And the ITO crystalline structure directly determines the conductivity of ITO-deposited films.High conductive [sheet resis-tance ~120 Ω·square-1 (Ω·sq-1)] and transparent (above 76%) ITO thin films (240 nm thick) were obtained with a moderate sputtering power (about 60 W) and with an oxygen flow rate of 0.25 ml·min-1 (sccm) during the deposi-tion.These results show that the ITO-MC electrodes can find their potential application in optoelectrical devices.展开更多
The electrical and optical properties of the indium tin oxide (ITO)/epoxy composite exhibit dramatic variations as functions of the ITO composition and ITO particle size. Sharp increases in the conductivity in the v...The electrical and optical properties of the indium tin oxide (ITO)/epoxy composite exhibit dramatic variations as functions of the ITO composition and ITO particle size. Sharp increases in the conductivity in the vicinity of a critical volume fraction have been found within the framework of percolation theory. A conductive and insulating transition model is extracted by the ITO particle network in the SEM image, and verified by the resistivity dependence on the temperature. The dependence of the optical transmittance on the particle size was studied. Further decreasing the ITO particle size could further improve the percolation threshold and light transparency of the composite film.展开更多
This paper reports the preparation of antimony doped tin oxide crystalline powders by chemical coprecipitation method. The influence of sintering temperature and the sintering retention time on the thermal infrared em...This paper reports the preparation of antimony doped tin oxide crystalline powders by chemical coprecipitation method. The influence of sintering temperature and the sintering retention time on the thermal infrared emissivity is analysed. The thermal infrared reflectivity is measured and the optimum doping concentration is proposed.展开更多
The current electrolytic processes for magnesium(Mg)metal have several disadvantages,such as anhydrous magnesium chloride(MgCl_(2))preparation and generation of harmful chlorine(Cl_(2))gas.To overcome these drawbacks,...The current electrolytic processes for magnesium(Mg)metal have several disadvantages,such as anhydrous magnesium chloride(MgCl_(2))preparation and generation of harmful chlorine(Cl_(2))gas.To overcome these drawbacks,a novel Mg production process to produce high-purity Mg metal directly from magnesium oxide(MgO)was investigated in this study.The electrolysis of MgO was conducted using a liquid tin(Sn)cathode and a carbon(C)anode in the eutectic composition of a magnesium fluoride(MgF_(2))-lithium fluoride(LiF)molten salt under an applied voltage of 2.5 V at 1053-1113 K.Under certain conditions,the Mg-Sn alloys with Mg_(2)Sn and Mg(Sn)phases were obtained with a current efficiency of 86.6%at 1053 K.To produce high-purity Mg metal from the Mg-Sn alloy,vacuum distillation was conducted at 1200-1300 K for a duration of 5-10 h.Following the vacuum distillation,the concentration of Mg in the Mg-Sn alloy feed decreased from 34.1 to 0.17 mass%,and Mg metal with a purity of 99.999%was obtained at 1200 K.Therefore,the electrolytic process developed here is feasible for the production of high-purity Mg metal from MgO using an efficient method.展开更多
基金National Natural Science Foundation of China (50533060)
文摘Antimony-doped tin hydroxide colloid precipitates have been synthesized by hydrolysis of SnCl4 and SbCl3 using: (1) an ion-exchange hydrolysis to remove chlorine ions, and (2) isoamyl acetate as an azeotropic solvent to obviate water. The obtained dried powder is of high dispersivity without any need for further grinding. The size and dispersivity of the final particles are investigated with the aid of TG-DTA, BET, XRD and TEM. After having calcined, the antimony-doped tin oxide nanopowder possesses a tetragonal rutile structure with high dispersivity, uniform particles and low hard agglomeration.
基金Project(50471027) supported by the National Natural Science Foundation of China
文摘Antimony-doped tin hydroxide colloid precipitates were prepared by hydrolysis of SnCl4·5H2O and SbCl3 ethanol solutions. Isoamyl acetate was selected as azeotropic drying solvent and was compared with the most commonly used n-butanol solvent on treating precipitate for low hard agglomeration precursor powders. The FT-IR, BET, XRD, and TEM results of the precursor powders and calcinated antimony-doped tin oxide powders were recorded. The results demonstrate that isoamyl acetate is an excellent azeotropic drying solvent that can effectively prevent the agglomeration of particles and greatly improve the fluffiness of the obtained dried powders. After these precursor powders are calcined, antimony-doped tin oxide nanopowders with tetragonal rutile structure and high dispersivity can be obtained.
基金Innovation project of the key laboratory of ministry of educational (I MT04033012)
文摘In this paper, conductive antimony-doped tin oxide (ATO) composite particles is prepared by hydroxylation method of metal alcoxides. This method has many advantages such as little pollution, low-cost, simple sheet and equipment. The synthesis processing and the ATO nanoparticles are characterized by means of transmission electron microscope (TEM), X-ray diffraction (XRD), thermal gravimetric and differential thermal analysis, and BET. The results show that the ATO nanoparticles is tetragonal rutile crystal structure. TEM show that the particles are monodispersed with weak aggromation. The size of the particles calcinated at 700 is about 8nm. The specific areas are 153 m^2·g~ -1 . In addition to, ATO nanoparticles have good electric
基金supported by the National Innovation Agency of Portugal through the project Baterias 2030(Grant No.POCI-01-0247-FEDER-046109)J R E would like to acknowledge the Fundación General CSIC’s ComFuturo programme which has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No.101034263+2 种基金The authors appreciate Dr Laura Simonelli and Dr Vlad Martin Diaconescu for their assistance in XAS measurements at the beamline BL22-CLÆSS,ALBA synchrotron(experiment AV-2022025706)R M is grateful to the Portuguese Foundation for Science and Technology(FCT)for the doctoral grant(Grant No.2021.06496.BD)R M and A M are grateful for the financial support from:LA/P/0045/2020,UIDB/00511/2020 and UIDP/00511/2020,funded by the national funds through FCT/MCTES(PIDDAC)。
文摘Proton exchange membrane(PEM)water electrolysis represents a promising technology for green hydrogen production,but its widespread deployment is greatly hindered by the indispensable usage of platinum group metal catalysts,especially iridium(Ir)based materials for the energy-demanding oxygen evolution reaction(OER).Herein,we report a new sequential precipitation approach to the synthesis of mixed Ir-nickel(Ni)oxy-hydroxide supported on antimony-doped tin oxide(ATO)nanoparticles(IrNiyO_(x)/ATO,20 wt.%(Ir+Ni),y=0,1,2,and 3),aiming to reduce the utilisation of scarce and precious Ir while maintaining its good acidic OER performance.When tested in strongly acidic electrolyte(0.1 M HClO_(4)),the optimised IrNi1Ox/ATO shows a mass activity of 1.0 mAµgIr^(−1) and a large turnover frequency of 123 s^(−1) at an overpotential of 350 mV,as well as a comparatively small Tafel slope of 50 mV dec^(−1),better than the IrOx/ATO control,particularly with a markedly reduced Ir loading of only 19.7µgIr cm^(−2).Importantly,IrNi1O_(x)/ATO also exhibits substantially better catalytic stability than other reference catalysts,able to continuously catalyse acidic OER at 10 mA cm^(−2) for 15 h without obvious degradation.Our in-situ synchrotron-based x-ray absorption spectroscopy confirmed that the Ir^(3+)/Ir^(4+)species are the active sites for the acidic OER.Furthermore,the performance of IrNi1Ox/ATO was also preliminarily evaluated in a membrane electrode assembly,which shows better activity and stability than other reference catalysts.The IrNi1Ox/ATO reported in this work is a promising alternative to commercial IrO_(2) based catalysts for PEM electrolysis.
基金supported by a grant from the Korean Ministry of Education, Science, and Technology (MEST)Republic of Korea through the National Research Foundation (NRF) (No. 2017-R1C1B2011968)
文摘Antimony-doped tin oxide(ATO) nanoparticles with an average size of ~ 6 nm were prepared by co-precipitation and subsequent heat treatment. Graphitic carbon nitride(g-CN)/ATO hybrid nanocomposite was designed by the combination of thermally synthesized g-CN and ATO nanoparticles by ultrasonication. The materials were characterized using N2 adsorption/desorption(BET), X-ray diffraction(XRD), scanning electron microscopy(SEM), energy dispersive spectroscopy(EDS), transmission electron microscopy(TEM) and Fourier transform infrared spectroscopy(FTIR). A mixture of five volatile organic compounds(VOCs, chloroform, benzene, toluene, xylene and styrene) was used to compare the adsorption capacity of the samples. The adsorption capacity of ATO nanoparticles was improved by the addition of g-CN. Experimental data showed that, among the five VOCs,chloroform was the least adsorbed, regardless of the samples. The g-CN/ATO showed nearly three times greater adsorption capacity for the VOC mixture than pure ATO. The unchanged efficiency of VOC adsorption during cyclic use demonstrated the completely reversible adsorption and desorption behavior of the nanocomposite at room conditions. This economically and environmentally friendly material can be a practical solution for outdoor and indoor VOC removal.
基金Projects (20676016,21076024) supported by the National Natural Science Foundation of China
文摘Tin oxide nanociystals with diameters smaller than 10 nm were synthesized using Na2SnO3 and CO2 as reactants and cetyltrimethylammonium bromide(CTAB) as stabilizer under mild conditions.As a mild acidic gas,CO2 is favorable for the accurate adjustment of pH value of Na2SnO3 solution.Stannate salt is stable,cheap and easy in operation.The effects of Na2SnO3concentration,CTAB concentration,aging temperature,and aging time on the nanociystals were studied.It was found that,with the increasing Na2SnO3 concentration,aging temperature and aging time,SnO2 nanociystals size decreases.The formation of SnO2nanociystals can be interpreted by electrostatic-interaction mechanism.SnO2 nanociystals show high photocatalytic activities in the degradation of Rhodamine B solution.The catalytic activity of small nanocrystals is higher than that of large ones.
基金supported by the National Natural Science Foundation of China (51320105001, 51372190, 21573170, 51272199, 21433007)the National Basic Research Program of China (973 program, 2013CB632402)+2 种基金the Natural Science Foundation of Hubei Province (2015CFA001)the Fundamental Research Funds for the Central Universities (WUT: 2015-Ⅲ-034)Innovative Research Funds of SKLWUT (2015-ZD-1)~~
文摘Flower-like tin oxide-supported platinum(Pt/SnOx) with a hierarchical structure was synthesized by a hydrothermal method and characterized by XRD,SEM,TEM,high resolution TEM,XPS and nitrogen adsorption.The flower-like Pt/SnOx microspheres of 1 μm in diameter were composed of staggered petal-like nanosheets with a thickness of 20 nm.Pt nanoparticles(NPs) of 2-3 nm were well dispersed on the SnOx nanosheets.The catalyst was tested in the catalytic oxidation of gaseous formaldehyde(HCHO) at room temperature,and exhibited enhanced activity compared to Pt NPs supported on commercial SnO and ground SnOx.HCHO removal of 87%was achieved over the hierarchical Pt/SnOx after 1 h of reaction,which was 1.5 times that over the ground SnOx-supported Pt(Pt/g-SnOx),and the high activity was maintained after six recycles,showing the high stability of this catalyst.HCHO decomposition kinetics was modeled as a second order reaction.The reaction rate constant for Pt/SnOx was 5.6 times higher than Pt/g-SnOx.The hierarchical pore structure was beneficial for the diffusion and adsorption of HCHO molecules,and the highly dispersed Pt NPs on the SnOx nanosheets were the active sites for the oxidative decomposition of HCHO into CO2 and H2O.This study provided a promising approach for designing efficient catalysts for indoor HCHO removal at ambient temperature.
基金supported by the National High-Tech Research and Development Program of China(No. 2004AA303542)
文摘The present work mainly describes the technology for preparing indium-tin oxide (ITO) targets by cold isostatic pressing (CIP) and normal pressure sintering process. ITO powders were produced by chemical co-precipitation and shaped into an ITO green compact with a relative density of 60% by CIP under 300 MPa. Then, an ITO target with a relative density larger than 99.6% was obtained by sintering this green compact at 1550℃ for 8 h. The effects of forming pressure, sintering temperature and sintering time on the density of the target were inves- tigated. Also, a discussion was made on the sintering atmosphere.
基金supported by the National Natural Science Foundation of China (21373259, 21301107)the Hundred Talents Project of the Chinese Academy of Sciences, the Strategic Priority Research Program of the Chinese Academy of Sciences (XDA09030102)+2 种基金the Open Funding from Key Laboratory of Interfacial Physics and Technology, Chinese Academy of Sciencesthe Fundamental Research Fund-ing of Shandong University (2014JC005)the Taishan Scholar Project of Shandong Province (China)~~
文摘Nanostructured gold catalyst supported on metal oxide is highly active for the CO oxidation reac‐tion. In this work, a new type of oxide support, zinc tin oxide, has been used to deposit 0.7 wt%Au via a deposition‐precipitation method. The textural properties of Zn2SnO4 support have been tuned by varying the molar ratio between base (N2H4·H2O) and metal ion (Zn2+) to be 4/1, 8/1 and 16/1. The catalytic tests for CO oxidation reaction revealed that the reactivity on Au‐Zn2SnO4 with N2H4·H2O/Zn2+ = 8/1 was the highest, while the reactivity on Au‐Zn2SnO4 with N2H4·H2O/Zn2+ =16/1 was almost identical to that of the pure support. Both fresh and used catalysts have been characterized by multiple techniques including nitrogen adsorption‐desorption, X‐ray diffraction, transmission electron microscopy, high‐angle annular dark‐field scanning transmission electron microscopy, X‐ray photoelectron spectroscopy, X‐ray adsorption fine structure, and tempera‐ture‐programmed reduction by hydrogen. These demonstrated that the textural properties, espe‐cially pore volume and pore size distribution, of Zn2SnO4 play crucial roles in the averaged size of gold nanoparticles, and thus determine the catalytic activity of Au‐Zn2SnO4 for CO oxidation.
基金financially supported by Key Research Program of the Chinese Academy of Sciences (ZDRW-ZS-2016-3)the National Key Research and Development Program of China (2016YFB0600901)the Instrument Developing Project of the Chinese Academy of Sciences
文摘Tin/tin oxide materials are key electrocatalysts for selective conversion of CO;to formate/formic acid.Herein we report a tin oxide material with nitrogen doping by using ammonia treatment at elevated temperature. The N doped material demonstrated enhanced electrocatalytic CO;reduction activity, showing high Faradaic efficiency(90%) for formate at -0.65 V vs. RHE with partial current density of 4 mA/cm;.The catalysis was contributed to increased electron negativity of N atom compared to O atom. Additionally, the N-doped catalyst demonstrates sulfur tolerance with retained formate selectivity. The analysis after electrolysis shows that the catalyst structure partially converts to metallic Sn, and thus the combined Sn/N-SnO;is the key for the active CO;catalysis.
文摘Silver tin oxide composite powders were synthesized by the hydrothermal method with a silver ammine solution and a Na2SnO3 solution as raw materials. H2C2O4 was used as the co-precipitator of silver ions and tin ions. The co-precipitation conditions were investigated. The results show that the co-precipitate of Ag2C2O4 and Sn(OH)4 is available when the pH value of the solution is 4.27-8.36. Using the obtained precipitate as precursor,the reduction of Ag+ and the crystallization of tin oxide were carried out simultaneously by the hydrothermal method and silver tin oxide composite powders were obtained. The composite powders were characterized by X-ray diffraction (XRD) analysis,scanning electron microscope (SEM),and energy spectrum analysis. The results show that the silver tin oxide composite powders are small with a diameter of about 2 μm and with homogeneous distribution of tin.
文摘A SnO-graphite composite material, which can deliver high capacities and good cycling stability compared with unsupported SnO, was described. This material prepared via chemical co-precipitation reaction in the presence of graphite consists of high dispersion of SnO with a size of about several hundred nanometers in the graphite. The phase structure was analyzed by X-ray diffraction (XRD). The morphology and the element distribution were examined by scanning electron microscopy (SEM) equipped with energy spectrum. The results show that the SnO-graphite composites produced by slowly hydrolysis have higher rechargeable capacities than pure graphite and better cycling performance than SnO.
基金supported by Shenzhen Science and Technology Innovation Commission(Project no.JCYJ20170413154602102)the Project of Strategic Importance provided by Hong Kong Polytechnic University(Project no.1-ZE29)+1 种基金National High Technology Research and Development Program(Project no.2015AA050601)the National Natural Science Foundation of China(Project nos.11674252,61376013,91433203)
文摘The emergence of hybrid organic-inorganic metal halide perovskite solar cells (PSCs) causes a break through in the solar technology recently due to its fabrication processes. The dramatic enhancenlent in in 2009 to the recent certified record PCE of 22.7% superior optoelectronic properties and the low-cost power conversion efficiency (PCE) of PSCs flom 3.8% ndicates huge potential of PSCs for future high efficiency and large scale photovoltaic manufacturing. The electron selective layer (ESL) plays an important role in electron extraction and hole blocking function in PSCs, and there have been great interest in developing efficient ESL materials. Recently, tin oxide (SnO2) as an ESL has attracted significant research attentions owing to its low temperature preparation processes as well as yielding high PCE and good stability of PSCs. In this perspective article, we focus on the development progress of SnO2 as an ESL m PSCs, and discuss the strategies for preparing SnO2 to achieve PSCs with high efficiency, less hysteresis and good device stability.
基金Project supported by the National Natural Science Foundation of China (Grant Nos.61290305 and 91021020)the Natural Science Foundation of Zhejiang Province,China (Grant No.Z6100117)
文摘Annealing effect on the performance of fully transparent thin-film transistor (TTFT), in which zinc tin oxide (ZnSnO) is used as the channel material and SiO2 as the gate insulator, is investigated. The ZnSnO active layer is deposited by radio frequency magnetron sputtering while a SiO2 gate insulator is formed by plasma-enhanced chemical vapor deposition. The saturation field-effect mobility and on/off ratio of the TTFT are improved by low temperature annealing in vacuum. Maximum saturation field-effect mobility and on/off ratio of 56.2 cm2/(V.s) and 3×10^5 are obtained, respectively. The transfer characteristics of the ZnSnO TPT are simulated using an analytical model and good agreement between measured and the calculated transfer characteristics is demonstrated.
文摘Indium tin oxide(ITO)thin films(100±10nm)were deposited on PC(polycarbonate)and glass substrates by rf(radio-frequency)mannetron spuutering.The oxygen content of the ITO films was changed by variation of the sputtering gas composition.All the other deposition parameters were kept constant.The sheet resistance.optical transmittance and microstructure of ITO films were investigated using a four-point probe.spectrophotometer,X-ray diffractometer(XRD)and atomic force microscope(AFM).Sheet resistances for the ITO films with optical transmittance more than 75% on PC substrates varied from 40Ω/cm^2 to more than 104 Ω/cm^2 with increasing oxygen partial pressure from O to about 2%.The same tendeney of sheet resistances increasing with increasing oxygen partial pressure was observed on glass substrates.The X-ray diffraction data indicated polycrystalline filns with grain orientations predominantly along(440)and (422)directions.The intensities of (440)and (422)peaks increased slightly with the increase of oxygen partial pressure both on PC and glass substrates.The AFM images show that the ITO films on PC substrates were dense and uniform.The average grain size of the films was about 40nm.
文摘Nanostructured tin dioxide (SnO2) powders were prepared by a sol-gel dialytic process and and the doping of CuO on it was completed by a deposition-precipitation method.The thick film sensors were fabricated from the CuO/SnO2 polycrystalline powders.Sensing behavior of the sensor was investigated with various gases including CO,H2,NH3,hexane,acetone,ethanol,methanol and H2S in air.The as-synthesized gas sensor had much better response to H2S than to other gases.At the same time,the CuO/SnO2 sensor had enough sensitivity,together with fast response and recovery,to distinguish H2S from those gases at 160 and 210 ℃.Therefore,it might have promising applications in the future.
基金Supported by the National Natural Science Foundation of China (10776014) Nanjing University of Science and Technology (NUST) Research Funding
文摘Microbial cellulose (MC) membranes produced by Acetobacter xylinum NUST4.1,were used as flexible substrates for the fabrication of transparent indium tin oxide (ITO) electrodes.Transparent and conductive ITO thin films were deposited on MC membrane at room temperature using radio frequency (RF) magnetron sputtering.The optimum ITO deposition conditions were achieved by examining crystalline structure,surface morphology and op-toelectrical characteristics with X-ray diffraction (XRD),scanning electron microscopy (SEM),atomic force mi-croscopy (AFM),and UV spectroscopy.The sheet resistance of the samples was measured with a four-point probe and the resistivity of the film was calculated.The results reveal that the preferred orientation of the deposited ITO crystals is strongly dependent upon with oxygen content (O2/Ar,volume ratio) in the sputtering chamber.And the ITO crystalline structure directly determines the conductivity of ITO-deposited films.High conductive [sheet resis-tance ~120 Ω·square-1 (Ω·sq-1)] and transparent (above 76%) ITO thin films (240 nm thick) were obtained with a moderate sputtering power (about 60 W) and with an oxygen flow rate of 0.25 ml·min-1 (sccm) during the deposi-tion.These results show that the ITO-MC electrodes can find their potential application in optoelectrical devices.
基金supported by the National Natural Science Foundation of China(Grant Nos.61222501 and 61335004)
文摘The electrical and optical properties of the indium tin oxide (ITO)/epoxy composite exhibit dramatic variations as functions of the ITO composition and ITO particle size. Sharp increases in the conductivity in the vicinity of a critical volume fraction have been found within the framework of percolation theory. A conductive and insulating transition model is extracted by the ITO particle network in the SEM image, and verified by the resistivity dependence on the temperature. The dependence of the optical transmittance on the particle size was studied. Further decreasing the ITO particle size could further improve the percolation threshold and light transparency of the composite film.
文摘This paper reports the preparation of antimony doped tin oxide crystalline powders by chemical coprecipitation method. The influence of sintering temperature and the sintering retention time on the thermal infrared emissivity is analysed. The thermal infrared reflectivity is measured and the optimum doping concentration is proposed.
基金supported by the National Research Council of Science and Technology(NST)grant by the Korea government(MSIT)(No.CRC-1506-KIGAM)。
文摘The current electrolytic processes for magnesium(Mg)metal have several disadvantages,such as anhydrous magnesium chloride(MgCl_(2))preparation and generation of harmful chlorine(Cl_(2))gas.To overcome these drawbacks,a novel Mg production process to produce high-purity Mg metal directly from magnesium oxide(MgO)was investigated in this study.The electrolysis of MgO was conducted using a liquid tin(Sn)cathode and a carbon(C)anode in the eutectic composition of a magnesium fluoride(MgF_(2))-lithium fluoride(LiF)molten salt under an applied voltage of 2.5 V at 1053-1113 K.Under certain conditions,the Mg-Sn alloys with Mg_(2)Sn and Mg(Sn)phases were obtained with a current efficiency of 86.6%at 1053 K.To produce high-purity Mg metal from the Mg-Sn alloy,vacuum distillation was conducted at 1200-1300 K for a duration of 5-10 h.Following the vacuum distillation,the concentration of Mg in the Mg-Sn alloy feed decreased from 34.1 to 0.17 mass%,and Mg metal with a purity of 99.999%was obtained at 1200 K.Therefore,the electrolytic process developed here is feasible for the production of high-purity Mg metal from MgO using an efficient method.