This paper examines the growth of ZnO thin films on glass substrate at 350 ℃ using an ultrasonic spray technique. We have investigated the influence of growth time ranging from 1 to 4 min on structural, optical and e...This paper examines the growth of ZnO thin films on glass substrate at 350 ℃ using an ultrasonic spray technique. We have investigated the influence of growth time ranging from 1 to 4 min on structural, optical and electrical properties of ZnO thin films. The as-grown films exhibit a hexagonal structure wurtzite and are （002） oriented. The maximum value of grain size G = 63.99 nm is attained for ZnO films grown at 2 min. The average transmittance is about 80%, thus the films are transparent in the visible region. The optical gap energy is found to increase from 3.26 to 3.37 eV with growth time increased from 1 to 2 min. The minimum value of electrical resistivity of the films is 0.13 Ω.cm obtained at 2 min. A systematic study on the influence of growth time on the properties of ZnO thin films deposited by ultrasonic spray at 350 ℃ has been reported.展开更多
Pure WOand Yb:WOthin films have been synthesized by spray pyrolysis technique. Effect of Yb doping concentration on photoelectrochemical, structural, morphological and optical properties of thin films are studied. X-r...Pure WOand Yb:WOthin films have been synthesized by spray pyrolysis technique. Effect of Yb doping concentration on photoelectrochemical, structural, morphological and optical properties of thin films are studied. X-ray diffraction analysis shows that all thin films are polycrystalline nature and exhibit monoclinic crystal structure. The 3 at% Yb:WOfilm shows superior photoelectrochemical（PEC） performance than that of pure WOfilm and it shows maximum photocurrent density（Iph= 1090 μA/cm） having onset potentials around +0.3 V/SCE in 0.01 M HClO. The photoelectrocatalytic process is more effective than that of the photocatalytic process for degradation of methyl orange（MO） dye. Yb doping in WOphotocatalyst is greatly effective to degrade MO dye. The enhancement in photoelectrocatalytic activity is mainly due to the suppressing the recombination rate of photogenerated electron-hole pairs. The mineralization of MO dye in aqueous solution is studied by measuring chemical oxygen demand（COD） values.展开更多
Thin film catalysts have been recently reported as promising catalysts owing to their good catalytic activity and reduced material amount, leading to low-cost efficient catalysts for gaseous emissions control. Here, w...Thin film catalysts have been recently reported as promising catalysts owing to their good catalytic activity and reduced material amount, leading to low-cost efficient catalysts for gaseous emissions control. Here, we report the slight loading of Cu in cobalt spinel using a one-step pulsed-spray evaporation chemical vapor deposition(PSE-CVD) synthesis technique for efficient short-chain volatile organic compounds(VOCs) emissions treatment. Crystalline structure and morphology analyses revealed nano-crystallite sizes and open-like morphology. The catalytic performance was evaluated through the complete oxidation of C_3H_6, as a short-chain representative model of VOCs, at a high gas hourly space velocity(GHSV). Very good activity was obtained towards the complete abatement of C_3H_6 at low temperature and no carbon monoxide(CO) was formed during the oxidation process. Slightly-promoted Co_3O_4 catalyst with Cu introduction resulted in high catalytic activity comparing to the performance of the catalysts in the literature, due to the high dispersion of Cu and high active surface oxygen amount. Moreover, to evaluate the capability of the used catalysts under near realistic reaction conditions, CO_2 effect on the catalytic activity was performed and the catalyst exhibited very good results. Thus, the adopted slightly-doping strategy to tailor a high active catalyst at low temperature could establish a very promising route to strongly enhance the activity of such other catalysts towards gas emissions abatement at low temperature.展开更多
BaTiO3 thin film has been deposited on Si(100) substrate using sol-gel process and deposited by using spin – coating technique. The BaTiO3/Si(100) structures were studied by structural and electrical characteristics....BaTiO3 thin film has been deposited on Si(100) substrate using sol-gel process and deposited by using spin – coating technique. The BaTiO3/Si(100) structures were studied by structural and electrical characteristics. The X-ray diffrac-tion of BaTiO3/Si(100) shows that the diffraction peaks become increasing sharp with increasing calcination tempera-tures indicating the enhance crystallinity of the films. Scanning electron microscopy of BaTiO3 thin films shows the crack free and uniform nature. The capacitance-voltage measurement of BaTiO3 thin film deposited on Si(100) an-nealed at 600℃ shows large frequency dispersion in the accumulation region. The current-voltage measurement of BaTiO3/Si shows the ideality factor was approaches to unity at 600℃.展开更多
文摘This paper examines the growth of ZnO thin films on glass substrate at 350 ℃ using an ultrasonic spray technique. We have investigated the influence of growth time ranging from 1 to 4 min on structural, optical and electrical properties of ZnO thin films. The as-grown films exhibit a hexagonal structure wurtzite and are （002） oriented. The maximum value of grain size G = 63.99 nm is attained for ZnO films grown at 2 min. The average transmittance is about 80%, thus the films are transparent in the visible region. The optical gap energy is found to increase from 3.26 to 3.37 eV with growth time increased from 1 to 2 min. The minimum value of electrical resistivity of the films is 0.13 Ω.cm obtained at 2 min. A systematic study on the influence of growth time on the properties of ZnO thin films deposited by ultrasonic spray at 350 ℃ has been reported.
基金University Grants Commission(UGC),New Delhi,for the financial support through the project No.‘‘41-869/2012(SR)’’
文摘Pure WOand Yb:WOthin films have been synthesized by spray pyrolysis technique. Effect of Yb doping concentration on photoelectrochemical, structural, morphological and optical properties of thin films are studied. X-ray diffraction analysis shows that all thin films are polycrystalline nature and exhibit monoclinic crystal structure. The 3 at% Yb:WOfilm shows superior photoelectrochemical（PEC） performance than that of pure WOfilm and it shows maximum photocurrent density（Iph= 1090 μA/cm） having onset potentials around +0.3 V/SCE in 0.01 M HClO. The photoelectrocatalytic process is more effective than that of the photocatalytic process for degradation of methyl orange（MO） dye. Yb doping in WOphotocatalyst is greatly effective to degrade MO dye. The enhancement in photoelectrocatalytic activity is mainly due to the suppressing the recombination rate of photogenerated electron-hole pairs. The mineralization of MO dye in aqueous solution is studied by measuring chemical oxygen demand（COD） values.
基金the financial support from the Ministry of Science and Technology of China (2017YFA0402800)Natural Science Foundation of China (No. 91541102/51476168)the support of Chinese Academy of Sciences for senior international scientists (Grant No. 2017PE009)the financial support of CAS-TWAS scholarship
文摘Thin film catalysts have been recently reported as promising catalysts owing to their good catalytic activity and reduced material amount, leading to low-cost efficient catalysts for gaseous emissions control. Here, we report the slight loading of Cu in cobalt spinel using a one-step pulsed-spray evaporation chemical vapor deposition(PSE-CVD) synthesis technique for efficient short-chain volatile organic compounds(VOCs) emissions treatment. Crystalline structure and morphology analyses revealed nano-crystallite sizes and open-like morphology. The catalytic performance was evaluated through the complete oxidation of C_3H_6, as a short-chain representative model of VOCs, at a high gas hourly space velocity(GHSV). Very good activity was obtained towards the complete abatement of C_3H_6 at low temperature and no carbon monoxide(CO) was formed during the oxidation process. Slightly-promoted Co_3O_4 catalyst with Cu introduction resulted in high catalytic activity comparing to the performance of the catalysts in the literature, due to the high dispersion of Cu and high active surface oxygen amount. Moreover, to evaluate the capability of the used catalysts under near realistic reaction conditions, CO_2 effect on the catalytic activity was performed and the catalyst exhibited very good results. Thus, the adopted slightly-doping strategy to tailor a high active catalyst at low temperature could establish a very promising route to strongly enhance the activity of such other catalysts towards gas emissions abatement at low temperature.
文摘BaTiO3 thin film has been deposited on Si(100) substrate using sol-gel process and deposited by using spin – coating technique. The BaTiO3/Si(100) structures were studied by structural and electrical characteristics. The X-ray diffrac-tion of BaTiO3/Si(100) shows that the diffraction peaks become increasing sharp with increasing calcination tempera-tures indicating the enhance crystallinity of the films. Scanning electron microscopy of BaTiO3 thin films shows the crack free and uniform nature. The capacitance-voltage measurement of BaTiO3 thin film deposited on Si(100) an-nealed at 600℃ shows large frequency dispersion in the accumulation region. The current-voltage measurement of BaTiO3/Si shows the ideality factor was approaches to unity at 600℃.
