THE INVESTIGATION OF CARBON NANOPARTICLES EMBEDDED IN ZnO And NiO AS SELECTIVE SOLAR ABSORBER SURFACES
Selective solar absorber coatings of carbon nanoparticles embedded in ZnO and NiO matrices on rolled aluminium substrates have been fabricated by a low cost acetate sol-gel technique. Spectrophotometry was used to determine the solar absorptance and the thermal emittance at 100 ℃ of the composite coatings in the wavelength range 0.3 to 20 μm. The surface morphology of the samples was studied by scanning electron microscopy (SEM). Cross-sectional high resolution transmission electron microscopy (X-HRTEM) was used to study the fine structure of the samples. Samples were subjected to an accelerated ageing test in a climate chamber with 95％ relative humidity and a temperature of 45 ℃. The SEM studies showed that C-NiO surface was smooth while that of the C-ZnO sample had micro roughness. The X-HRTEM investigations revealed a nanocrystalline nature of C-NiO sample and a layered structure for the C-ZnO samples. The thermal emittances of the samples were 6％ for the C-ZnO and 4％ for the C-NiO matrix materials. The solar absorptances were 71％ and 84％ for the C-ZnO and C-NiO samples, respectively. The accelerated ageing tests produced performance criterion (PC) values of 0.04 and 0.007 at 95 hours for the C-ZnO and C-NiO samples, respectively. Based on these results, C-NiO matrix sample proved to have better solar selectivity behaviour than the C-ZnO counterpart.
G.Katumba A.Forbes B.Mwakikunga E.W(a)ckelg(a)rd J.Lu L.Olumekor G.Makiwa
Physics Department, University of Zimbabwe, P.O.Box MP 167, Mt.Pleasant, Harare, Zimbabwe. Council for Scientific and Industrial Research, National Laser Centre, P.O.Box 395, Pretoria 0001, S Council for Scientific and Industrial Research, National Centre for Nanostructured Materials, P.O.Bo Division of Solid State Physics, Department of Engineering Sciences, Uppsala University, P.O.Box 534 Division of Electron Microscopy, and Nanoengineering, Department of Engineering Sciences, Uppsala Un
国际会议
2007世界太阳能大会(Proceedings of ISES Solar World Congress 2007)
北京
英文
2007-09-18（万方平台首次上网日期，不代表论文的发表时间）