The initial stage of Ni-TiO2 composite system electrodeposition on glassy carbon electrode from an acidic solution of nickel sulfate was investigated using cyclic voltammetry （CV）, chronoamperometry （CA） and elect...The initial stage of Ni-TiO2 composite system electrodeposition on glassy carbon electrode from an acidic solution of nickel sulfate was investigated using cyclic voltammetry （CV）, chronoamperometry （CA） and electrochemical impedance spectroscopy （EIS）. Analysis of current density-time transients was performed using the nonlinear fitting procedure and electrochemical impedance spectroscopy was simulated by Z-view software. Besides, the surface morphology of Ni-TiO2 co-deposition at the initial stage was observed by scanning electron microscopy （SEM）. The results show that, in the case of low overpotential （-790 mV vs SCE）, the presence of TiO2 particles in the plating bath makes the nucleation relaxation time tm^x decreased clearly. Meanwhile, the electro-crystallization of Ni-TiO2 system follows a Scharifker-Hills （SH） progressive nucleation/growth mechanism. While in the case of higher overpotential, the presence of the TiO2 particles in solution makes the nucleation relaxation time tmax increased. At -850 mV （vs SCE）, the co-deposition of Ni-TiO2 system meets SH instantaneous nucleation/growth mechanism. The results of impedance spectra show that the appearance of the characteristic inductive loops represents the nucleation/growth of nickel and the presence of TiO2 particles reduces the charge transfer resistance of solution. The SEM observation confirms that TiO2 particles can be considered as favorable sites for nickel nucleating.展开更多
[Objective] The aim was to study the adsorption property of adsorbent Ni-TiO2-SiO2 synthesized by using rice husks as silicon source and template to gentian violet.[Method] The renewable dye adsorbent Ni-TiO2-SiO2 was...[Objective] The aim was to study the adsorption property of adsorbent Ni-TiO2-SiO2 synthesized by using rice husks as silicon source and template to gentian violet.[Method] The renewable dye adsorbent Ni-TiO2-SiO2 was synthesized by using rice husks as raw material,and the adsorption property of Ni-TiO2-SiO2 to gentian violet was studied.[Result] The adsorption rate of Ni-TiO2-SiO2 to gentian violet reached about 90% after 1 h.In 100 ml gentian violet solution with concentration of 25 mg/L and pH=8,Ni-TiO2-SiO2 with dosage of 0.07 g had the best adsorption effect.More importantly,Ni-TiO2-SiO2 as adsorbent could be used repeatedly,and couldn’t lead to secondary pollution due to leaking.[Conclusion] The study could provide references for practical engineering application.展开更多
The grain growth and thermal stability of nanocrystalline Ni-TiO2composites were systematically investigated.Thenanocrystalline Ni-TiO2composites with different contents of TiO2were prepared via electroplating method ...The grain growth and thermal stability of nanocrystalline Ni-TiO2composites were systematically investigated.Thenanocrystalline Ni-TiO2composites with different contents of TiO2were prepared via electroplating method with the variation ofTiO2nano-particles concentration.The effect of TiO2content on the grain size,phase structure and microhardness was investigatedin detail.The corresponding grain growth and diffusion mechanisms during the heating process were also discussed.The optimalmicrohardness of HV50270was achieved for the composite with addition of20g/L TiO2nano-particles after annealing at400°C for90min.The calculation of the activation energy indicated that lattice diffusion dominated at high temperatures for thenanocrystalline Ni-TiO2composites.It was indicated that the increase of TiO2nano-particles content took effect on restricting thegrain growth at high temperatures by increasing the grain growth activation energy.展开更多
基金Project(MKPT-04-106) supported by the Project of National Defense of China
文摘The initial stage of Ni-TiO2 composite system electrodeposition on glassy carbon electrode from an acidic solution of nickel sulfate was investigated using cyclic voltammetry （CV）, chronoamperometry （CA） and electrochemical impedance spectroscopy （EIS）. Analysis of current density-time transients was performed using the nonlinear fitting procedure and electrochemical impedance spectroscopy was simulated by Z-view software. Besides, the surface morphology of Ni-TiO2 co-deposition at the initial stage was observed by scanning electron microscopy （SEM）. The results show that, in the case of low overpotential （-790 mV vs SCE）, the presence of TiO2 particles in the plating bath makes the nucleation relaxation time tm^x decreased clearly. Meanwhile, the electro-crystallization of Ni-TiO2 system follows a Scharifker-Hills （SH） progressive nucleation/growth mechanism. While in the case of higher overpotential, the presence of the TiO2 particles in solution makes the nucleation relaxation time tmax increased. At -850 mV （vs SCE）, the co-deposition of Ni-TiO2 system meets SH instantaneous nucleation/growth mechanism. The results of impedance spectra show that the appearance of the characteristic inductive loops represents the nucleation/growth of nickel and the presence of TiO2 particles reduces the charge transfer resistance of solution. The SEM observation confirms that TiO2 particles can be considered as favorable sites for nickel nucleating.
基金Supported by Research Funds of Educational Commission of Yunnan Province(09Y0392)Scientific Research Funds of Qujing Normal University(2009QN032)+1 种基金Teaching Reform Project of Qujing Normal University about " Key Course of Analytical Chemistry" and " Excellent Course of Instrumental Analysis"Scientific Funds of Baoshan University(11B004K)
文摘[Objective] The aim was to study the adsorption property of adsorbent Ni-TiO2-SiO2 synthesized by using rice husks as silicon source and template to gentian violet.[Method] The renewable dye adsorbent Ni-TiO2-SiO2 was synthesized by using rice husks as raw material,and the adsorption property of Ni-TiO2-SiO2 to gentian violet was studied.[Result] The adsorption rate of Ni-TiO2-SiO2 to gentian violet reached about 90% after 1 h.In 100 ml gentian violet solution with concentration of 25 mg/L and pH=8,Ni-TiO2-SiO2 with dosage of 0.07 g had the best adsorption effect.More importantly,Ni-TiO2-SiO2 as adsorbent could be used repeatedly,and couldn’t lead to secondary pollution due to leaking.[Conclusion] The study could provide references for practical engineering application.
基金Project(51401024)supported by the National Natural Science Foundation of ChinaProject(20150942006)supported by Basic Research Program of Beijing Institute of Technology,China
文摘The grain growth and thermal stability of nanocrystalline Ni-TiO2composites were systematically investigated.Thenanocrystalline Ni-TiO2composites with different contents of TiO2were prepared via electroplating method with the variation ofTiO2nano-particles concentration.The effect of TiO2content on the grain size,phase structure and microhardness was investigatedin detail.The corresponding grain growth and diffusion mechanisms during the heating process were also discussed.The optimalmicrohardness of HV50270was achieved for the composite with addition of20g/L TiO2nano-particles after annealing at400°C for90min.The calculation of the activation energy indicated that lattice diffusion dominated at high temperatures for thenanocrystalline Ni-TiO2composites.It was indicated that the increase of TiO2nano-particles content took effect on restricting thegrain growth at high temperatures by increasing the grain growth activation energy.
