The preparation of Tri-Hybrid Nanofluids (CuO-SiO2-TiO2) in water-ethylene glycol mixture for solar thermal application

Nowadays, energy consumption of typical electric water heater is typically high and it depends on the usage of electricity. The demand of electricity is growing rapidly and keeps on growing at a warning rate. Therefore, the renewable energy such as solar energy is one of the ways out to overcome the energy crisis. Thus, in this study is to prepare tri-hybrid nanofluids (CuO-SiO2-TiO2). The objectives of this study are to prepare homogenized solution of CuO, SiO2 and TiO2 as tri-hybrid nanofluids in water-ethylene glycol, to analyse the stability by visualization effect, ultraviolet-visible spectrophotometer (UV-Vis), scanning electron microscopy (SEM), fourier transform infrared spectroscopy (FT-IR) and x-ray diffraction (XRD) and finally to study the heat transfer performance of optimized prepared tri-hybrid nanofluids in water-ethylene glycol mixture. From the UV-Vis analysis that was conducted, the absorbance of 0.1% was the most stable among other samples. SEM image of CuO-SiO2-TiO2 nanoparticles shows an appearance of those three nanoparticles, indicating the tri-hybrid nanoparticles formation. From XRD, the crystallites size of CuO, SiO2 and TiO2 are identified, which at 21 nm,<10 nm and 13 nm respectively. Whilst, the performance observed for 0.2% tri-hybridnanofluid is the highest among the others. Hence, from the series of analysis, it can be concluded that the tri-hybrid nanofluids were successfully prepared and achieved good stability. It is suggested to continue this study by focusing on various of the concentration of nanofluids in order to maximise the heat transfer performance.