Preparation and direct photothermal property of reduced graphene oxide @copper foam cured MIL-101 for solar adsorption cooling process

Abstract

Since the energy and environment issues, a renewable and sustainable solar adsorption cooling technology has attracted extensive attention. In order to improve the energy conversion efficiency in the solar adsorption cooling technology, a novel reduced graphene oxide (rGO) @copper foam cured MIL-101 (CFCM) composite with direct illumination property was explored in this paper. The preparation process and photothermal desorption performance of rGO@CFCM were studied. A solar adsorption cooling system with rGO@CFCM-water working pair was designed and constructed. Temperature characteristic curve of rGO@CFCM adsorber, the specific cooling power (SCP) and solar coefficient of performance (SCOP) of rGO@CFCM-water working pair were investigated. The results show that the rGO@CFCM with the carbon/oxygen ratio of 5.43, amount of rGO of 1.6 g m−2, thickness of copper foam of 10 mm owns great photothermal heating rate and desorption performance for water. The heating rate of rGO@CFCM is 0.90 ℃ min−1 with desorption percentage of water of 84.36% and energy conversing efficiency of 0.7573 under the irradiation intensity of 2 kW m−2 within 60 min. The light-to-heat conversion performance of rGO@CFCM composite is significantly improved through the addition of rGO. Even if 20 sets of adsorption/photothermal desorption, the adsorption capacity of rGO@CFCM for water still keep stable. SCP and SCOP of the rGO@CFCM-water adsorption cooling system is 85.38 W kg−1 and 0.163 at evaporation temperature of 17 ℃, respectively. It provides basic data for solar adsorption cooling technology.