1. Surface structural and solar absorptance features of nitrate-based copper-cobalt oxides composite coatings: Experimental studies and molecular dynamic simulation
- Author
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M. Iqbal, Ahmad Fadli, Zhong-Tao Jiang, Hantarto Widjaja, M. Mahbubur Rahman, Silvia Reni Yenti, Neni Frimayanti, Syamsu Herman, Gadang Priyotomo, Amun Amri, Muhammad Miftahul Munir, and Chun-Yang Yin
- Subjects
Materials science ,Annealing (metallurgy) ,Process Chemistry and Technology ,chemistry.chemical_element ,Nanoparticle ,02 engineering and technology ,engineering.material ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Copper ,Selective surface ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,chemistry ,Coating ,X-ray photoelectron spectroscopy ,Chemical engineering ,Absorptance ,Materials Chemistry ,Ceramics and Composites ,engineering ,0210 nano-technology ,Cobalt - Abstract
The copper and cobalt oxides composites coatings on aluminum substrates have been successfully synthesized via sol-gel method using nitrate-based sol precursors. The composites were characterized by X-ray Diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Field Emission Scanning Electron Microscopy (FESEM), Atomic Force Microscopy (AFM), and UV-Vis-NIR spectrophotometry. The sol-gel reactions were discussed and Molecular Dynamics (MD) simulation was integrated into the study to predict molecules assembly properties. The XRD analyses revealed that the CuO and the Co3O4 composites were formed after the annealing process with the average difference of the calculated lattice parameters compared to ICDDs was 1.17%. The surface electronic structure was mainly consisted of tetrahedral Cu(I), octahedral Cu(II), tetrahedral Co(II), octahedral Co(III) as well as surface, sub-surface and lattice oxygen O−. The XRD, XPS and MD simulation results showed that there was minimal (or possibly non-existing) indication of copper-cobalt mixed phase oxides formations. FESEM and AFM surveys revealed that the coating had a porous surface composed of interlinked nanoparticles in the range of ~10 to ~40 nm. UV-Vis-NIR reflectance spectra showed that the sol precursors concentration and the dip-drying cycle significantly influenced the absorptance value with optimum absorptance (α) of 88.7% exhibited by coating synthesized using sol concentration of 0.1 M and 10 dip-drying cycles. High absorptance value and simplicity in the synthesis process render the coatings to be very promising candidates for solar selective absorber (SSA) applications.
- Published
- 2018