Nanocrystalline copper oxide (CuO) thin films were deposited onto glass substrates by a spin coating technique using an aqueous solution of copper acetate. These films were characterized for their structural, mor-phol...Nanocrystalline copper oxide (CuO) thin films were deposited onto glass substrates by a spin coating technique using an aqueous solution of copper acetate. These films were characterized for their structural, mor-phological, optoelectronic properties by means of X-ray diffraction (XRD) scanning electron microscopy (SEM), UVspectroscopy and four probe method. The CuO films are oriented along (1 1 1) plane with the monoclinic crystal structure. These films were utilized in H2S sensors. The dependence of the H2S response on the operating temperature, H2S concentration of CuO film (annealed at 700。C) was investigated. The CuO film showed selectivity for H2S. The maximum H2S response of 25.2 % for the CuO film at gas concentra-tion of 100 ppm at operating temperature 200oC was achieved.展开更多
Solar energy is becoming more popular and widespread, and consequently, the materials to manufacture solar cells are becoming more limited and costly. Therefore, in order to keep solar energy affordable and available,...Solar energy is becoming more popular and widespread, and consequently, the materials to manufacture solar cells are becoming more limited and costly. Therefore, in order to keep solar energy affordable and available, we must research alternative materials such as copper oxides. Some benefits of copper oxides include being available in abundance, affordable, low toxicity, low bandgap, and a high absorption coefficient—all of which contribute to it being a valuable interest for the manufacturing of solar cells. In this study, CuO thin films were synthesized utilizing RF sputtering technique with deposition occurring at room temperature followed by thermal annealing between 100°C and 400<span style="white-space:normal;">°</span>C and using different gases, oxygen (O<sub>2</sub>) (oxidizing and reactive gas) and nitrogen (N<sub>2</sub>) (inert gas), besides air. Afterwards, these thin films were evaluated for a range of wavelengths: 200 - 400 nm (UV spectrum), 400 - 700 nm (Visible spectrum), and 700 - 800 nm (IR spectrum), for both, optical transmittance and photoluminescence. In addition, the CuO results were compared to our Cu<sub>2</sub>O results from a previous study to assess their differences. In the results of this study, the CuO thin film initially had a bandgap of 2.19 eV at room temperature, and by increasing the annealing temperature to different levels, the bandgap decreased respectively. The presence of air in the chamber allowed for the highest decrease, followed by the nitrogen (N<sub>2</sub>) and the lowest decrease was observed in the presence of oxygen (O<sub>2</sub>). This was reflected in the decrease in the bandgap values from 2.19 eV (room temperature) to 2.05 eV for the films annealed at 400<span style="white-space:normal;">°</span>C.展开更多
Composite photocatalysts of CuO/CoFe2O4-TiO2 were successfully synthesized by a sol-gel method and fixed on ordinary tiles. The photosterilization of Escherichia coli was examined on CuO/CoFe2O4-TiO2 thin films under ...Composite photocatalysts of CuO/CoFe2O4-TiO2 were successfully synthesized by a sol-gel method and fixed on ordinary tiles. The photosterilization of Escherichia coli was examined on CuO/CoFe2O4-TiO2 thin films under a xenon lamp irradiation. The film was characterized by XRD, and the morphology was observed by SEM. Disinfection data indicated that CuO/CoFe2O4-TiO2 composite photocatalysts have the much better photocatalytic activity than CuO/CoFe2O4 and TiO2. The optimized composition of the nanocomposites has been found to be CuO/CoFe2O4： mTio2=3：7, with loadings ranging from 790 to 1400 mg/m2. The photocatalytic inactivated rate of E. coli （105 CFU/mL） reached 98.4% under the xenon lamp of 150 W within 30 min.展开更多
Efficient mixing and thermal control are important in the flow reactor for obtaining a high product yield and selectivity.Here,we report a heterogeneous chemical kinetic study of propene oxidation within a newly desig...Efficient mixing and thermal control are important in the flow reactor for obtaining a high product yield and selectivity.Here,we report a heterogeneous chemical kinetic study of propene oxidation within a newly designed catalytic jet-stirred reactor(CJSR).To better understand the interplay between the catalytic performances and properties,the CuO thin films have been characterized and the adsorbed energies of propene on the adsorbed and lattice oxygen were calculated using density functional theory(DFT)method.Structure and morphology analyses revealed a monoclinic structure with nano-crystallite size and porous microstructure,which is responsible for holding an important quantity of adsorbed oxygen.The residence time inside the flow CJSR(1.12–7.84 s)makes it suitable for kinetic study and gives guidance for scale-up.The kinetic study revealed that using CJSR the reaction rate increases with O_2concentration that is commonly not achievable for catalytic flow tube reactor,whereas the reaction rate tends to increase slightly above 30%of O_2due to the catalyst surface saturation.Moreover,DFT calculations demonstrated that adsorbed oxygen is the most involved oxygen,and it has found that the pathway of producing propene oxide makes the reaction of C_3H_6over CuO surface more likely to proceed.Accordingly,these findings revealed that CJSR combined with theoretical calculation is suitable for kinetic study,which can pave the way to investigate the kinetic study of other exhaust gases.展开更多
文摘Nanocrystalline copper oxide (CuO) thin films were deposited onto glass substrates by a spin coating technique using an aqueous solution of copper acetate. These films were characterized for their structural, mor-phological, optoelectronic properties by means of X-ray diffraction (XRD) scanning electron microscopy (SEM), UVspectroscopy and four probe method. The CuO films are oriented along (1 1 1) plane with the monoclinic crystal structure. These films were utilized in H2S sensors. The dependence of the H2S response on the operating temperature, H2S concentration of CuO film (annealed at 700。C) was investigated. The CuO film showed selectivity for H2S. The maximum H2S response of 25.2 % for the CuO film at gas concentra-tion of 100 ppm at operating temperature 200oC was achieved.
文摘Solar energy is becoming more popular and widespread, and consequently, the materials to manufacture solar cells are becoming more limited and costly. Therefore, in order to keep solar energy affordable and available, we must research alternative materials such as copper oxides. Some benefits of copper oxides include being available in abundance, affordable, low toxicity, low bandgap, and a high absorption coefficient—all of which contribute to it being a valuable interest for the manufacturing of solar cells. In this study, CuO thin films were synthesized utilizing RF sputtering technique with deposition occurring at room temperature followed by thermal annealing between 100°C and 400<span style="white-space:normal;">°</span>C and using different gases, oxygen (O<sub>2</sub>) (oxidizing and reactive gas) and nitrogen (N<sub>2</sub>) (inert gas), besides air. Afterwards, these thin films were evaluated for a range of wavelengths: 200 - 400 nm (UV spectrum), 400 - 700 nm (Visible spectrum), and 700 - 800 nm (IR spectrum), for both, optical transmittance and photoluminescence. In addition, the CuO results were compared to our Cu<sub>2</sub>O results from a previous study to assess their differences. In the results of this study, the CuO thin film initially had a bandgap of 2.19 eV at room temperature, and by increasing the annealing temperature to different levels, the bandgap decreased respectively. The presence of air in the chamber allowed for the highest decrease, followed by the nitrogen (N<sub>2</sub>) and the lowest decrease was observed in the presence of oxygen (O<sub>2</sub>). This was reflected in the decrease in the bandgap values from 2.19 eV (room temperature) to 2.05 eV for the films annealed at 400<span style="white-space:normal;">°</span>C.
基金Project supported by the Natural Science Foundation of China （No. 20876039） Aid Program for Science and Technology Innovative Research Team in Higher Educational Instituions of Hunan Province.
文摘Composite photocatalysts of CuO/CoFe2O4-TiO2 were successfully synthesized by a sol-gel method and fixed on ordinary tiles. The photosterilization of Escherichia coli was examined on CuO/CoFe2O4-TiO2 thin films under a xenon lamp irradiation. The film was characterized by XRD, and the morphology was observed by SEM. Disinfection data indicated that CuO/CoFe2O4-TiO2 composite photocatalysts have the much better photocatalytic activity than CuO/CoFe2O4 and TiO2. The optimized composition of the nanocomposites has been found to be CuO/CoFe2O4： mTio2=3：7, with loadings ranging from 790 to 1400 mg/m2. The photocatalytic inactivated rate of E. coli （105 CFU/mL） reached 98.4% under the xenon lamp of 150 W within 30 min.
基金financial support from the Ministry of Science and Technology of China (2017YFA0402800)the National Natural Science Foundation of China (51476168 and 91541102)+1 种基金Recruitment Program of Global Youth Expertsthe support of Chinese Academy of Sciences for senior international scientists within the framework of PIFI program (2017PE0009)
文摘Efficient mixing and thermal control are important in the flow reactor for obtaining a high product yield and selectivity.Here,we report a heterogeneous chemical kinetic study of propene oxidation within a newly designed catalytic jet-stirred reactor(CJSR).To better understand the interplay between the catalytic performances and properties,the CuO thin films have been characterized and the adsorbed energies of propene on the adsorbed and lattice oxygen were calculated using density functional theory(DFT)method.Structure and morphology analyses revealed a monoclinic structure with nano-crystallite size and porous microstructure,which is responsible for holding an important quantity of adsorbed oxygen.The residence time inside the flow CJSR(1.12–7.84 s)makes it suitable for kinetic study and gives guidance for scale-up.The kinetic study revealed that using CJSR the reaction rate increases with O_2concentration that is commonly not achievable for catalytic flow tube reactor,whereas the reaction rate tends to increase slightly above 30%of O_2due to the catalyst surface saturation.Moreover,DFT calculations demonstrated that adsorbed oxygen is the most involved oxygen,and it has found that the pathway of producing propene oxide makes the reaction of C_3H_6over CuO surface more likely to proceed.Accordingly,these findings revealed that CJSR combined with theoretical calculation is suitable for kinetic study,which can pave the way to investigate the kinetic study of other exhaust gases.
