New Technology of Electroless Silver Plating on Fly Ash Cenospheres with Thermo-Alkaline Activation

2014 ◽  
Vol 941-944 ◽  
pp. 1616-1620
Author(s):  
Ya Min Li ◽  
Xing Huo Gang Xu

Electroless silver plating on the surface of fly ash cenospheres was prepared by slowly adding the solution of AgNO3 into the mixed solution of D-glucose solution and alkaline solution after thermo-alkaline treatment. The morphology and composition of the silver-coated fly ash cenospheres composite powders were observed and analyzed by using SEM, EDS and XRD, and the influence of pH, loading quantity on silver plating was invested. The results revealed that, with the pH value of plating solution increasing, the precipitation of silver is improved, but led to self-accelerating decomposition if too high, and the influence of loading quantity on silver relative content and electro-conductivity of composite powders is very great. The silver shell of composite particles is even and compact when the pH value is 12.57 and the loading quantity is 4g/L, which resistivity can reach to 0.05Ω•cm.

2013 ◽  
Vol 800 ◽  
pp. 256-259
Author(s):  
Wang Qun ◽  
Ye Fan Li ◽  
Dong Mei Li ◽  
Zhi Xue Qu

The Ag coating was deposited on the surface of Al-Ag alloy powder by electroless plating process. 10 wt% of AgNO3 was put in the powder for precursor replacement reaction, and then added the powder into electroless plating bath which contained glucose solution, solution of silver ammonia, thiourea solution, tartaric acid solution and absolute ethanol. The effects of formula components were analyzed. The surface morphology of the prepared composite particles was studied with SEM and their chemical compositions were confirmed by XRD. With the chemical etching method, silver content of the powder was determined. The studies have shown that an uniform, complete and dense silver coating for the Al-Ag composite powders was generated by this method, with the silver content being 20wt%, and the conductivity was favorable.


Materials ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 3550 ◽  
Author(s):  
Wang ◽  
Wang ◽  
Bai ◽  
Yang ◽  
Wang

Calcined fly ash (CFA) was first obtained by calcining fly ash (FA) at 815 °C for two hours. Then, composite powders of CFA coated with zinc oxide nanoparticles (ZnO/CFA, ZCFA) were prepared by heterogeneous nucleation method. The samples were characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, Scanning electronic microscopy (SEM), Whiteness, and Brunauer-Emmett-Teller specific surface area (BET). Effects of pH value, reaction temperature and time, coating amount, solid-to-liquid ratio, the coating agent concentrations, and dropping speed on the whiteness of ZCFA powders were studied. It was shown that after coated with ZnO particles, the whiteness of CFA was increased from 27.0 to 62.6%, and the specific surface area was increased from 5.80 to 14.61 m2/g. Needle ZnO with the average grain size of 46 nm was deposited on the surface of CFA. Si–O–Zn–OH bonds were formed.


2016 ◽  
Vol 4 (2) ◽  
pp. 19
Author(s):  
MENEZES CRAIG ◽  
RATHOD AJIT P ◽  
WASEWAR KAILAS L. ◽  
◽  
◽  
...  

2013 ◽  
Vol 28 (4) ◽  
pp. 387-392
Author(s):  
Tong SUN ◽  
Lian-Li LIU ◽  
Shu-Ying XU ◽  
Xiao-Lin PENG ◽  
Hai-Long YANG

2011 ◽  
Vol 686 ◽  
pp. 378-381
Author(s):  
Si Rong Yu ◽  
Zhi Qiu Huang ◽  
Jia An Liu

Novel AZ91D Mg alloy/fly-ash cenospheres (AZ91D/FAC) composites were fabricated by melt stir technique. The thermodynamic analyses of the interfacial reactions, the microstructure observation, and the phase analyses of the AZ91D/FAC composites were investigated. The results showed that the cenospheres were almost filled with Mg alloy matrix. In-situ MgO and Mg2Si phases were formed in Mg alloy matrix and near the interfaces between the cenospheres and Mg alloy matrix. Through the thermodynamic calculation, it can be found that the standard free enthalpy changes of these interfacial reactions are all negative at the temperature of Mg alloy melt preparation in this work, and these reactions can occur.


2011 ◽  
Vol 44 (44) ◽  
pp. 445301 ◽  
Author(s):  
Qin Li ◽  
Bing Wang ◽  
Chuang Li ◽  
Jianfeng Pang ◽  
Jianping Zhai

2016 ◽  
Vol 69 (1) ◽  
pp. 119 ◽  
Author(s):  
Li Lin ◽  
Ya Wang ◽  
Manhong Huang ◽  
Donghui Chen

Three-dimensional (3D) BiOBr/BiOI hierarchical microspheres were successfully fabricated on the surface of fly ash cenospheres (FACs) via a facile one-pot solvothermal method for the first time. The as-prepared samples were characterized by XRD, SEM, energy-dispersive X-ray spectroscopy, UV–visible diffuse reflectance spectroscopy, and high-resolution transmission electron microscopy. The results indicated that the loaded hierarchical microspheres exhibited a uniform distribution, and some aggregation was observed. These well-dispersed hierarchical microspheres were composed of 2D nanosheets, which possess heterojunction structures. Based on the photodegradation tests examining the removal of rhodamine B from water under visible light irradiation (λ > 420 nm), the photocatalytic activity of BiOB/BiOI/FACs was superior to that of BiOBr/FACs and BiOI/FACs. A proposed mechanism for the enhanced photocatalytic activity displayed by BiOB/BiOI/FACs is discussed.


2013 ◽  
Vol 634-638 ◽  
pp. 1886-1889 ◽  
Author(s):  
Jing Zhang ◽  
Jiang Long Yu ◽  
Ping Yang Wang ◽  
Huan Zhao

The paper provides an overview of surface modification and application of fly ash cenospheres. The state of the art research and development of electromagnetic wave absorption materials based on surface treated fly ash cenospheres are summarized.


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