RESUMEN
The daily increase in the demand for energy consumption is partly caused by the global population explosion and advancements in technology. Humanity relies on energy to fulfil its daily routines, such as electricity for lighting, heating, cooling, and running electronic devices. There are continuous attempts by researchers and industry experts to optimize and enhance the efficiency of various sustainable energy generation devices. Solar collectors play a critical role in the renewable energy sector, which is vital in helping the world achieve a clean, green, and sustainable environment. Over the last two decades, researchers have made significant efforts to explore various techniques for enhancing the effectiveness of solar thermal collectors. Their effort has been centered around improving the fluid thermal properties, which act as the heat transfer medium in solar collectors. The discovery of nanofluids will help resolve some of the challenges associated with conventional fluid used in solar collectors. Enhancement through nanofluids is influenced by several factors, which include nanoparticle types, nanoparticle concentration, base fluid, and the purpose of its application. This review provides a technical summary of the application of nanofluids in the two main types of collectors: non-concentrating and concentrated thermal collectors. Findings from this study showed that TiO2 + Cu hybrid nanofluids with a mass fraction of 0.03 augment heat transfer coefficient by 21% in parabolic trough collectors. The merits of employing nanofluids as heat transfer fluids in solar collectors are examined, while also outlining the obstacles and areas where further research is needed.
RESUMEN
Perovskite types of nanocomposites of BiFeO3-GdFeO3 (BFO-GFO) has been synthesized using sol-gel route for the first time. The nanocomposite powders were characterized by powder X-Ray diffraction (PXRD) to confirm the existence of mixed crystallographic phases. EDX analysis on nanocomposites estimates the composition of individual element present in BFO-GFO matrix. The induced strain upon loading GdFeO3(GFO) in BiFeO3 (BFO) matrix has been computed with the aid of Williamson -Hall (W-H) plot. Surface morphologies of nanocomposite powders has been studied using Field Emission Scanning Electron Microscope (FESEM) images. The observed changes in the band gap energies of nanocomposite powders due to the inclusion of GFO has been ascertained from the tauc plots. PL emission of BFO upon loading GFO found to have detected in the IR region due to defect level transition. Finally, the methylene blue dye (MB) degradation characteristics of BFO, GFO and the nanocomposite powders of BFO-GFO have also been studied. The overall results obtained has been discussed in detail.
