Preparation And Photothermal Properties Researching Of Nanofluids And ATO Hollow Structure

The utilization of solar energy depends on the research and development of solar materials. Nanofluids, a new type of solar absorption materials, are worth researching. In this work, CuO aqueous nanofluids, Carbon black aqueous nanofluids, ATO aqueous nanofluids and ATO and CuO mixture aqueous nanofluids were prepared by dispersion method. Multishelled antimony-doped tin oxide (ATO) hollow spheres were synthesized by sacrificial template method. The photo-thermal conversion properties of the prepared nanofluids with different fractions were investigated. Carbon black aqueous nanofluids show strong photo-thermal conversion effect in the visible and near-infrared light region. CuO aqueous nanofluids show strong photo-thermal conversion efficiency in the visible light region. ATO aqueous nanofluids show strong photo-thermal conversion efficiency in near-infrared light region. ATO and CuO mixture aqueous nanofluids show strong absorption in the visible and near-infrared light region. Photo-thermal conversion property of ATO hollow spheres was also measured. The results are as follows:1) Under the illumination of 635 nm laser at 25 mW, carbon black aqueous nanofluids show a highest photo-thermal conversion efficiency of 70.54%. Under the illumination of 1064 nm laser at 25 mW, carbon black aqueous nanofluids show a highest photo-thermal conversion efficiency of 78.62%. Under the illumination of xenon lamp, carbon black aqueous nanofluids show a highest photo-thermal conversion efficiency of 39.24%.2) Under the illumination of 635 nm laser at 25 mW, CuO aqueous nanofluids show a highest photo-thermal conversion efficiency of 30.33%. Under the illumination of 1064 nm laser at 25 mW, the photo-thermal conversion efficiency of CuO aqueous nanofluids is close to zero. Under the illumination of xenon lamp, CuO aqueous nanofluids show a highest photo-thermal conversion efficiency of 30.67%.3) Under the illumination of 635 nm laser at 25 mW, ATO aqueous nanofluids show a highest photo-thermal conversion efficiency of 35.16%. Under the illumination of 1064 nm laser at 25 mW, ATO aqueous nanofluids show a highest photo-thermal conversion efficiency of 67.91%. Under the illumination of xenon lamp, ATO aqueous nanofluids show a highest photo-thermal conversion efficiency of 38.97%.4) Under the illumination of xenon lamp, ATO (0.05V%) and CuO (0.008V%) mixture aqueous nanofluids show a highest photo-thermal conversion efficiency of 40.22%.5) Single, double and triple layer ATO hollow spheres can be synthesis by controlling the reactants, concentrations, reaction temperature and sintering time. Under the illumination of 1064 nm laser at 25 mW, single layer ATO (0.1wt%) hollow spheres ethylene glycol nanofluids show a photo-thermal conversion efficiency of 21.53%; double layer ATO (0.1wt%) hollow spheres ethylene glycol nanofluids show a photo-thermal conversion efficiency of 26.57%; triple layer ATO (0.1wt%) hollow spheres ethylene glycol nanofluids show a photo-thermal conversion efficiency of 30.69%.Under the illumination of laser, photo-thermal conversion efficiency of carbon black nanofluids is better than that of ATO nanofluids or CuO nanofluids. Under the illumination of xenon lamp, photo-thermal conversion efficiency of ATO (0.05V%) and CuO (0.008V%) mixture aqueous nanofluids is better than that of black carbon aqueous nanofluids. Optical absorption and utilization efficiency of ATO hollow spheres can be influenced by the number of layers, increasing the number of layers results in higher photo-thermal conversion efficiency.