Preparation and investigation on thermal properties of copper oxide nanofluid for solar energy absorption

Abstract

Nanofluids are colloids of nanoparticles in a selected base fluid. The primary application of nanofluid is to increase the heat transfer extent of liquid coolants like water, ethylene glycol, oil etc. In the present work, Copper Oxide (CuO) nanoparticle is prepared by sol-gel technique from CuSO4.5H2O as a precursor material. CuO nanofluids are prepared by two-step method. In the first step, sol-gel synthesis technique is utilized and the second step involves dispersion by ultrasonication. To examine the crystallite size, shape, composition and surface area of prepared CuO nano particles are characterized by XRD, SEM, FTIR, and BET. Further, the heat absorption capacity is also investigated for the prepared CuO-water nanofluid with the varying weight fraction of 0.1, 0.2 and 0.3 in open sunlight. The maximum solar thermal absorption is reported for 0.3wt% CuO-water nanofluid.