Self‐Adaptive Solar‐Thermal System With Moss‐Like Surface for Efficient Energy Utilization

Abstract

ABSTRACT In order to achieve high‐efficiency solar utilization, inspired by the “black carpet effect” of moss population in cold regions, a self‐adaptive Janus solar–thermal system with the solar–thermal conversion‐conduction‐storage‐loss control ability is designed. The solar–thermal system features a composite phase change material (CPCM) thermal storage base and a moss‐like switchable solar–thermal surface. This surface is constructed from graphene skeletons containing graphene/polydopamine/MXene heterostructures and MXene secondary nano‐porous structures. High‐efficiency solar–thermal conversion (98.1%) is realized in this surface, due to the interlayer carrier interaction at the heterostructure, as proved by femtosecond transient absorption spectroscopy (fs‐TAS), Raman and photoluminescence (PL) spectroscopies, and multiscale calculations, along with the multiple reflections and absorption in porous structures. The converted thermal energy is then rapidly conducted (26.5 W/(m·K)) and stored (236.7 J/g) in the CPCM base. At night, the moss‐like surface with ultralow thermal conductivity of 0.03 W/(m·K) and emissivity of 0.2 greatly restrains the thermal loss to the external environment, thereby achieving long‐term thermal management (13.3 times longer than that without the system). This study utilized a systematic bioinspired design strategy for preparing the high‐performance solar–thermal system, which possesses broad potential for long‐term solar utilization.