Preparation and Photothermal Conversion of h‐BN/CuO Nanofluids

Abstract

A new h-BN/CuO nanocomposite was prepared by using boron nitride (h-BN) and CuSO 4 ⋅ 5H 2 O as raw materials via hydrothermal synthesis. We studied loading the CuO nanoparticles on sheet of h-BN substrate and the stability of the h-BN/CuO water-based (h-BN/CuO) nanofluids. It had both well light absorbing ability and photothermal conversion efficiency in direct absorption solar collectors (DASCs). The results show that different molar ratios of CuO to h-BN do not affect the size of CuO nanoparticles or h-BN substrates, but within a suitable feed ratio range, there exists an optimum feed ratio: h-BN/CuO 0.75 : 1 which the suspension stability is the best in the base fluid. Simultaneously, supporting CuO nanoparticles on h-BN substrate can make the absorption capacity of sunlight stronger than that of pure h-BN. Under the simulated sunlight source, the nanocomposite with feed ratio of 0.75 : 1 was selected for the photothermal conversion test. The highest photothermal temperature of 0.05 wt % h-BN/CuO nanofluid can reach 92.21 °C, which is 37.58 °C higher than pure water at most. Meanwhile, compared with 35.35 % for pure water, its photothermal conversion efficiency can rise to 80.18 %.