Gd-Co alloy films were synthesized by potentiostatic electrolysis on Cu substrates in urea-acetamide-NaBr-KBr melt at 353 K. The electroreduction of Co^2+ and Gd^3+ was investigated by cyclic voltammetry. The reduct...Gd-Co alloy films were synthesized by potentiostatic electrolysis on Cu substrates in urea-acetamide-NaBr-KBr melt at 353 K. The electroreduction of Co^2+ and Gd^3+ was investigated by cyclic voltammetry. The reduction of Co^2+ is an irreversible process. Gd^3+ cannot be reduced alone, but it can be inductively co-deposited with Co^2+. Both the Gd content and microstructure of the prepared Gd-Co alloy films can be controlled by the deposited potential. The content of Gd was analyzed using an inductively coupled plasma emission spectrometer (ICPES), and the microstructure was observed by scanning electron micrograph (SEM). The films were crystallized by heat-treatment at 823 K for 30 s in Ar atmosphere, and then were investigated by XRD. The hysteresis loops of the Gd-Co alloy films were measured by a vibrating sample magnetometer (VSM). The experimental results reveal that the deposited Gd-Co alloy films are amorphous, while the annealing causes the samples to change from amorphous to polycrystalline, thus enhancing their magnetocrystalline anisotropy and coercivity. Moreover, the magnetic properties of the Gd-Co alloy films depend strongly on the Gd content.展开更多
The oxidation behaviors of Fe26Cr1Mo with and without the Ni La 2O 3 electrodeposited composite film have been investigated by thermogravimetric analysis (TGA) and a scanning electron microscope equipped with an en...The oxidation behaviors of Fe26Cr1Mo with and without the Ni La 2O 3 electrodeposited composite film have been investigated by thermogravimetric analysis (TGA) and a scanning electron microscope equipped with an energy dispersive analytical X ray system(SEM/EDAX). The experimental results show that the oxide scale growing on Fe26Cr1Mo exposed at 900 ℃ spalled severely during cooling, while after the stainless steel was coated with the Ni La 2O 3 electrodeposited composite film, its high temperature cyclic oxidation resistance was significantly improved. The reason is that a La 2O 3 modified NiO scale, which has a superior adhesion to the substrate, was formed on the Fe26Cr1Mo stainless steel coated with Ni La 2O 3 composite film.展开更多
Cuprous oxide (Cu2O) thin films have been grown by electrodeposition technique onto ITO-coated glass substrates from aqueous copper acetate solutions with addition of sodium thiosulfate at 60 ℃ The effects of sodiu...Cuprous oxide (Cu2O) thin films have been grown by electrodeposition technique onto ITO-coated glass substrates from aqueous copper acetate solutions with addition of sodium thiosulfate at 60 ℃ The effects of sodium thiosulfate on the electrochemical deposition of Cu2O films were investigated by cyclic voltammetry and chronoamperometry techniques. Deposited films were obtained at - 0.58 V vs. SCE and characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FrIR), scanning electron microscopy (SEM), and optical, photoelectrochemical and electrical measurements. X-ray diffraction results indicated that the synthesized Cu2O films had a pure cubic phase with a marked preferential orientation peak along (200) plane and with lattice constants a = b = c = 0.425 rim. FFIR results confirmed the presence of Cu2O films at peak 634 cm 1. SEM images of Cu2O films showed a better compactness and spherical-shaped composition. Optical properties of Cu2O films reveal a high optical transmission (〉80%) and high absorption coefficient (α 〉 104 cm- 1 ) in visiblelight region. The optical energy band gap was found to be 2.103 eV. Photoelectrochemical measurements indicated that Cu2O films had n-type semiconductor conduction, which confirmed by Hall Effect measurements. Electrical properties of Cu2O films showed a low electrical resistivity of 61.30 Ω. cm-1, carrier concentration of-4.94×1015cm -3andmobility of20.61cm2.V 1,s-l.Theobtained Cu2O thin films with suitable properties are promising semiconductor material for fabrication of photovoltaic solar cells,展开更多
In this study, we prepared horn-like ZnO structures on carbon films(ZnO/CF) by electrodeposition and decorated the ZnO horns with different metals(Ag, Au, and Pt) via photodeposition(M-ZnO/CF). Using M-ZnO/CF as...In this study, we prepared horn-like ZnO structures on carbon films(ZnO/CF) by electrodeposition and decorated the ZnO horns with different metals(Ag, Au, and Pt) via photodeposition(M-ZnO/CF). Using M-ZnO/CF as photocatalysts, we examined ways to enhance solar hydrogen production from various points of view, such as modifying the intrinsic physical properties and thermodynamics of the materials, and varying the chemical environment during M-ZnO/CF fabrication. In particular, we focused on the effects of the carbon film and metals in M-ZnO/CF hybrid photocatalysts on solar hydrogen production. The type of metal nanoparticles is an important factor in solar hydrogen production because the deposition rate and electrical conductivity of each metal affect the proton-water reduction ability.展开更多
Copper antimony selenium(CuSbSe_(2))has advantages of adjustable band gaps from 1.09 eV to 1.2 eV,high light absorption coefficient(>105 cm-1),and low grain generation temperature(300—400℃),which is suitable for ...Copper antimony selenium(CuSbSe_(2))has advantages of adjustable band gaps from 1.09 eV to 1.2 eV,high light absorption coefficient(>105 cm-1),and low grain generation temperature(300—400℃),which is suitable for the preparation of solar cells.However,the stable range of CuSbSe_(2)(CASe)phase is narrow,which is inevitable to form Sb_(2)Se_(3)and Cu_(3)SbSe_(4)second phase during the preparation process.In this work,selenization annealing of Sb/Cu metal layer to prepare CASe thin films with pulse electrodeposition process was studied,and the growth mechanism of CASe film was analyzed.Cu and Sb reacted with Se to form Cu_(2)Se and Sb_(2)Se_(3),respectively.Then Cu_(2)Se and Sb_(2)Se_(3)further reacted to generate CASe.Since the formation temperature of Cu_(3)SbSe_(4)was lower than that of CASe,the preferential formation of Cu_(3)SbSe_(4)led to layer separation.When the annealing temperature was too high,CASe decomposed to form Cu_(3)SbSe_(3)and Sb_(2)Se_(3).Additionally,by increasing the heating rate,the separation of CASe thin films was effectively improved,and the CASe thin films with relatively high crystallinity were obtained at 360℃with heating rate of 30℃/min and selenization time of 20 min.展开更多
基金financially supported by the Science Foundation of the Educational Department of Fujian Prov-ince (No. 2008F5021)the Natural Science Foundation of Fujian Province (No. A0510013)the National Natural Science Foundation of China (No. 60676055)
文摘Gd-Co alloy films were synthesized by potentiostatic electrolysis on Cu substrates in urea-acetamide-NaBr-KBr melt at 353 K. The electroreduction of Co^2+ and Gd^3+ was investigated by cyclic voltammetry. The reduction of Co^2+ is an irreversible process. Gd^3+ cannot be reduced alone, but it can be inductively co-deposited with Co^2+. Both the Gd content and microstructure of the prepared Gd-Co alloy films can be controlled by the deposited potential. The content of Gd was analyzed using an inductively coupled plasma emission spectrometer (ICPES), and the microstructure was observed by scanning electron micrograph (SEM). The films were crystallized by heat-treatment at 823 K for 30 s in Ar atmosphere, and then were investigated by XRD. The hysteresis loops of the Gd-Co alloy films were measured by a vibrating sample magnetometer (VSM). The experimental results reveal that the deposited Gd-Co alloy films are amorphous, while the annealing causes the samples to change from amorphous to polycrystalline, thus enhancing their magnetocrystalline anisotropy and coercivity. Moreover, the magnetic properties of the Gd-Co alloy films depend strongly on the Gd content.
文摘The oxidation behaviors of Fe26Cr1Mo with and without the Ni La 2O 3 electrodeposited composite film have been investigated by thermogravimetric analysis (TGA) and a scanning electron microscope equipped with an energy dispersive analytical X ray system(SEM/EDAX). The experimental results show that the oxide scale growing on Fe26Cr1Mo exposed at 900 ℃ spalled severely during cooling, while after the stainless steel was coated with the Ni La 2O 3 electrodeposited composite film, its high temperature cyclic oxidation resistance was significantly improved. The reason is that a La 2O 3 modified NiO scale, which has a superior adhesion to the substrate, was formed on the Fe26Cr1Mo stainless steel coated with Ni La 2O 3 composite film.
基金Supported by the Algerian Ministry of Higher Education and Scientific Research(CNEPRU project number:J0101520090018)
文摘Cuprous oxide (Cu2O) thin films have been grown by electrodeposition technique onto ITO-coated glass substrates from aqueous copper acetate solutions with addition of sodium thiosulfate at 60 ℃ The effects of sodium thiosulfate on the electrochemical deposition of Cu2O films were investigated by cyclic voltammetry and chronoamperometry techniques. Deposited films were obtained at - 0.58 V vs. SCE and characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FrIR), scanning electron microscopy (SEM), and optical, photoelectrochemical and electrical measurements. X-ray diffraction results indicated that the synthesized Cu2O films had a pure cubic phase with a marked preferential orientation peak along (200) plane and with lattice constants a = b = c = 0.425 rim. FFIR results confirmed the presence of Cu2O films at peak 634 cm 1. SEM images of Cu2O films showed a better compactness and spherical-shaped composition. Optical properties of Cu2O films reveal a high optical transmission (〉80%) and high absorption coefficient (α 〉 104 cm- 1 ) in visiblelight region. The optical energy band gap was found to be 2.103 eV. Photoelectrochemical measurements indicated that Cu2O films had n-type semiconductor conduction, which confirmed by Hall Effect measurements. Electrical properties of Cu2O films showed a low electrical resistivity of 61.30 Ω. cm-1, carrier concentration of-4.94×1015cm -3andmobility of20.61cm2.V 1,s-l.Theobtained Cu2O thin films with suitable properties are promising semiconductor material for fabrication of photovoltaic solar cells,
基金supported by the DGIST R&D Program of Ministry of Science,ICT and Future Planning of Korea (16-NB-03)
文摘In this study, we prepared horn-like ZnO structures on carbon films(ZnO/CF) by electrodeposition and decorated the ZnO horns with different metals(Ag, Au, and Pt) via photodeposition(M-ZnO/CF). Using M-ZnO/CF as photocatalysts, we examined ways to enhance solar hydrogen production from various points of view, such as modifying the intrinsic physical properties and thermodynamics of the materials, and varying the chemical environment during M-ZnO/CF fabrication. In particular, we focused on the effects of the carbon film and metals in M-ZnO/CF hybrid photocatalysts on solar hydrogen production. The type of metal nanoparticles is an important factor in solar hydrogen production because the deposition rate and electrical conductivity of each metal affect the proton-water reduction ability.
基金the National Natural Science Foundation of China(Nos.61804108 and 62074084)。
文摘Copper antimony selenium(CuSbSe_(2))has advantages of adjustable band gaps from 1.09 eV to 1.2 eV,high light absorption coefficient(>105 cm-1),and low grain generation temperature(300—400℃),which is suitable for the preparation of solar cells.However,the stable range of CuSbSe_(2)(CASe)phase is narrow,which is inevitable to form Sb_(2)Se_(3)and Cu_(3)SbSe_(4)second phase during the preparation process.In this work,selenization annealing of Sb/Cu metal layer to prepare CASe thin films with pulse electrodeposition process was studied,and the growth mechanism of CASe film was analyzed.Cu and Sb reacted with Se to form Cu_(2)Se and Sb_(2)Se_(3),respectively.Then Cu_(2)Se and Sb_(2)Se_(3)further reacted to generate CASe.Since the formation temperature of Cu_(3)SbSe_(4)was lower than that of CASe,the preferential formation of Cu_(3)SbSe_(4)led to layer separation.When the annealing temperature was too high,CASe decomposed to form Cu_(3)SbSe_(3)and Sb_(2)Se_(3).Additionally,by increasing the heating rate,the separation of CASe thin films was effectively improved,and the CASe thin films with relatively high crystallinity were obtained at 360℃with heating rate of 30℃/min and selenization time of 20 min.