Fabrication of bilayered attapulgite for solar steam generation with high conversion efficiency

Abstract

Solar steam generation has been attracting wide attention for boosting the evolution of solar-energy-harvesting technology. Here, we demonstrate the fabrication of a novel bilayer photothermal material based on attapulgite/poly acrylamide composite (APAC), which was prepared by the solution polymerization of acrylamide (AM) in the presence of attapulgite using N, N′-Methylene bisacrylamide (MBA) as a crosslinker, for efficient solar steam generation. The APAC shows better thermal stability with a decomposition temperature of 250 °C, good mechanical property with a compress strength of up to 125 KPa at 75% strain and a low apparent density (0.0191 g·cm−3) with abundant porosity accompanying with a low thermal conductivity (0.07 W m−1 K−1). To enhance the light absorption of APAC, a thin carbon layer was created on the surface of APAC via a facile flame treatment. Under our conditions, the bilayered APAC shows a high vapor rate of 1.2 kg m−2 h−1 under 1 sun illumination, equal to 85% solar-to-vapor efficiency. With the merits of cost-efficient, scalable manufacture, high solar energy conversion efficiency, the APAC may hold the great potential as high-performance photothermal materials for solar energy generation.