A new cobalt oxide electrodeposit bath for solar absorbers

Barrera, Enrique; González, Ignacio; Viveros, T.

doi:10.1016/s0927-0248(97)00209-2

Cited by 88 publications

(50 citation statements)

References 8 publications

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“…The difference is the use of KNO 3 and H 2 SiF 6 for obtaining Cr 2 O 3 . KNO 3 acts as an oxidizing agent [31] while fluorosilicates stabilizes the oxide phase [32]. It has been reported that NO 3 − and fluoride compounds catalyze the formation of the oxide phase [32].…”

Section: Surface Characterizationmentioning

confidence: 99%

Electrochemical Investigation of the Hydrogen Evolution Reaction on Electrodeposited Films of Cr(OH)3 and Cr2O3 in Mild Alkaline Solutions

et al. 2017

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The hydrogen evolution reaction (HER) from water reduction is the main cathodic reaction in the sodium chlorate process. The reaction typically takes place on electrodes covered with a Cr(III) oxide-like film formed in situ by reduction of sodium dichromate in order to avoid reduction of hypochlorite and thereby increase the selectivity for the HER. However, the chemical structure of the Cr(III) oxide-like film is still under debate. In the present work, the kinetics of the HER were studied using titanium electrodes covered with electrodeposited Cr(OH) 3 or Cr 2 O 3 , which were characterized by means of scanning electron microscopy (SEM), energydispersive x-ray spectroscopy (EDX), x-ray photoelectron spectroscopy (XPS), and Raman spectroscopy. A clear difference in the morphology of the deposited surfaces was obtained, and the structure could be revealed with Raman spectroscopy. The kinetics for the HER were investigated using potentiodynamic and potentiostatic techniques. The results show that the first electron transfer is rate limiting and that the activity decreases in the order Cr 2 O 3 @Ti > bare Ti > Cr(OH) 3 @Ti. The low activity obtained for Cr(OH) 3 @Ti is discussed in terms of the involvement of structural water in the HER and the slow ligand exchange rate for water in Cr(III) complexes, while the high activity obtained for Cr 2 O 3 @Ti is rationalized by a surface area effect in combination with reduction of surface water and water in solution.

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Section: Surface Characterizationmentioning

confidence: 99%

Electrochemical Investigation of the Hydrogen Evolution Reaction on Electrodeposited Films of Cr(OH)3 and Cr2O3 in Mild Alkaline Solutions

et al. 2017

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“…The durability test showed that the coating had good stability at high temperatures of 450 °C for 48 h. However, the multiple repetitions of the coating using a fix speed rate of dip-coating had a weakness, namely it created many defects which influenced the mechanical and optical characteristics of the films [37]. As a comparison, the electrochemical method used to synthesize a cobalt oxide selective absorber on various substrates gives α=0.92-0.96 and ε=0.04-0.18 [76][77][78]. Overall, it can be concluded that the cobalt oxide selective absorber produced by the sol-gel dip-coating method is quite comparable with the electrochemical-based cobalt oxide selective absorber.…”

Section: Cobalt Oxide-based Absorbermentioning

confidence: 99%

Developments in the synthesis of flat plate solar selective absorber materials via sol–gel methods: A review

Amri

Jiang

Pryor

et al. 2014

Renewable and Sustainable Energy Reviews

144

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“…To avoid such hindrances, requirement of precise tracking and high cost engrossment will be needed, which add some more minuses to the proposed design. Effort on solar selective coatings by Farooq and Raja (2008) [4] and cobalt electrodeposition on absorber tubes by Barrera et al (1998) [5] enhance the efficiency for performance of solar devices. But radiation thermal losses may increase with increase in coating temperature, thus results in development of high thermal stresses in the collector tube.…”

Section: Introductionmentioning

confidence: 99%

Absorber Tube with Internal Pin-Fins for Solar Parabolic Trough Collector

Kalidasan¹,

Shankar

Srinivas

2016

MATEC Web of Conferences

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Abstract. Solar parabolic trough collectors exploit solar energy for power generation in solar thermal power stations. These systems require long arrays of reflective troughs with absorber tube running along the axis of parabolic dish. A successful attempt to reduce the length of arrays was accomplished by experimentally analysing the modifications done in absorber tube. Two out of three tubes were fabricated and they were employed to obtain the performance parameters through experimentation conducted at VIT University, Vellore, India. Distilled water was used as the working fluid. Maximum efficiency of 39.12% was obtained at 451.6 W/m 2 of direct normal irradiance (DNI) for absorber tube with internal pin-fins and without glass tube (AFWG t ) compared to 8.15% obtained at same value of DNI and other conditions for simple absorber tube without glass cover (AWG t ). Cylindrical parabolic trough available at the university was utilized, providing the basis for designing and fabrication of the tubes. Plots for varying mass flow rate at interval of 10 minutes were made against instantaneous thermal efficiency and heat utilized, for direct normal irradiance vs. temperature difference across the tubes and instantaneous thermal efficiency. Through the experimentation conducted, better performance was procured compared to earlier works. Thus, the proposal infers that absorber tube with internal fins has good scope for its application, both domestically as well as industrially. It also calls for further research and development of proposed techniques so as to achieve better performance curves.

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A new cobalt oxide electrodeposit bath for solar absorbers

Cited by 88 publications

References 8 publications

Electrochemical Investigation of the Hydrogen Evolution Reaction on Electrodeposited Films of Cr(OH)3 and Cr2O3 in Mild Alkaline Solutions

Electrochemical Investigation of the Hydrogen Evolution Reaction on Electrodeposited Films of Cr(OH)3 and Cr2O3 in Mild Alkaline Solutions

Developments in the synthesis of flat plate solar selective absorber materials via sol–gel methods: A review

Absorber Tube with Internal Pin-Fins for Solar Parabolic Trough Collector

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