Silane coupling reagent (3-aminopropyltriethoxysilane (APTES)) was prepared on single-crystal silicon substrates to form two-dimensional self-assembled monolayer (SAM). The terminal-NH2 groups in the film were in situ...Silane coupling reagent (3-aminopropyltriethoxysilane (APTES)) was prepared on single-crystal silicon substrates to form two-dimensional self-assembled monolayer (SAM). The terminal-NH2 groups in the film were in situ phosphorylated to -PO(OH)2 group to endow the film with good chemisorption ability. Then La-based thin films were deposited on phosphorylated APTES-SAM in order to make good use of the chemisorption ability of -PO(OH)2 groups. The thickness of the film was determined with ellipsometer, while phase transformation and surface morphology, surface energy, phase composition were analyzed by means of atomic force microscope (AFM), contact angle measurements and X-ray photoelectron spectroscopy (XPS). The results indicated that the terminal-NH2 groups could be completely transformed into desirable-PO(OH)2 groups after phosphorylation of APTES-SAM. Detailed XPS analysis of the La3+ peaks revealed that lanthanum element existed in the films in different states. As a result, conclusion could be made that lanthanum reacted with -PO(OH)2 groups on the surface of the substrate by chemical bond which would improve the bonding strength between the film and silicon substrate. Since the La-based thin films were well adhered to the silicon substrate, it might find promising application in the surface-modification of single-crystal Si and SiC in microelectromechanical systems (MEMS).展开更多
Utilizing microbial fuel cells( MFCs) is a promising technology for energy-efficient domestic wastewater treatment,but it still faces practical barriers such as low power generation. In this study,the LaMnO_3 perovski...Utilizing microbial fuel cells( MFCs) is a promising technology for energy-efficient domestic wastewater treatment,but it still faces practical barriers such as low power generation. In this study,the LaMnO_3 perovskite-type oxide nanoparticles and nickel oxide/carbon nanotube/polyaniline( NCP) nanocomposite( the cathode and anode catalysts,respectively) have been prepared and used to enhance power density of MFC. The prepared La-based perovskite oxide catalysts were characterized by X-ray diffraction( XRD) and scanning electron microscopies( SEM). The electrocatalytic properties of the prepared catalysts were investigated through cyclic voltammetry( CV) and electrochemical impedance spectroscopy( EIS) and Tafel plot at ambient temperature. Results show the exchange current densities of LaMnO_3/carbon cloth cathode and NCP nanocomposite/carbon cloth anode were 1.68 and 7 times more compared to carbon cloth cathode,respectively. In comparison to the bare carbon cloth anode,the MFC with the modified electrodes shows 11 times more enhancement in power density output which according to electrochemical results,it can be due to the enhancement of the electron transfer capability. These cathodic and anodic catalysts were examined in batch and semicontinuous modes to provide conditions close to industrial conditions. This study suggests that utilizing these low cost catalysts has promising potential for wastewater treatment in MFC with high power generation and good COD removal efficiency.展开更多
基金Project supported by the National Natural Science Foundation of China (50475023)
文摘Silane coupling reagent (3-aminopropyltriethoxysilane (APTES)) was prepared on single-crystal silicon substrates to form two-dimensional self-assembled monolayer (SAM). The terminal-NH2 groups in the film were in situ phosphorylated to -PO(OH)2 group to endow the film with good chemisorption ability. Then La-based thin films were deposited on phosphorylated APTES-SAM in order to make good use of the chemisorption ability of -PO(OH)2 groups. The thickness of the film was determined with ellipsometer, while phase transformation and surface morphology, surface energy, phase composition were analyzed by means of atomic force microscope (AFM), contact angle measurements and X-ray photoelectron spectroscopy (XPS). The results indicated that the terminal-NH2 groups could be completely transformed into desirable-PO(OH)2 groups after phosphorylation of APTES-SAM. Detailed XPS analysis of the La3+ peaks revealed that lanthanum element existed in the films in different states. As a result, conclusion could be made that lanthanum reacted with -PO(OH)2 groups on the surface of the substrate by chemical bond which would improve the bonding strength between the film and silicon substrate. Since the La-based thin films were well adhered to the silicon substrate, it might find promising application in the surface-modification of single-crystal Si and SiC in microelectromechanical systems (MEMS).
文摘Utilizing microbial fuel cells( MFCs) is a promising technology for energy-efficient domestic wastewater treatment,but it still faces practical barriers such as low power generation. In this study,the LaMnO_3 perovskite-type oxide nanoparticles and nickel oxide/carbon nanotube/polyaniline( NCP) nanocomposite( the cathode and anode catalysts,respectively) have been prepared and used to enhance power density of MFC. The prepared La-based perovskite oxide catalysts were characterized by X-ray diffraction( XRD) and scanning electron microscopies( SEM). The electrocatalytic properties of the prepared catalysts were investigated through cyclic voltammetry( CV) and electrochemical impedance spectroscopy( EIS) and Tafel plot at ambient temperature. Results show the exchange current densities of LaMnO_3/carbon cloth cathode and NCP nanocomposite/carbon cloth anode were 1.68 and 7 times more compared to carbon cloth cathode,respectively. In comparison to the bare carbon cloth anode,the MFC with the modified electrodes shows 11 times more enhancement in power density output which according to electrochemical results,it can be due to the enhancement of the electron transfer capability. These cathodic and anodic catalysts were examined in batch and semicontinuous modes to provide conditions close to industrial conditions. This study suggests that utilizing these low cost catalysts has promising potential for wastewater treatment in MFC with high power generation and good COD removal efficiency.
