Carrot-inspired solar thermal evaporator

Abstract

Solar steam generation appears as an emerging green strategy due to its potential applications in water desalination, power generation and chemical purification. Although a variety of efforts have been devoted to developing high-efficiency solar steam generation devices, a number of challenges remain, including the relatively low thermal efficiency, the complicated process, the high cost, and the difficulty in cycling. Herein, inspired by the natural water transportation in plants, a cheap carrot-inspired solar thermal evaporator (ethanol-treated-carrot biochar, ECB) has been reported by utilizing its inherent structure, which achieves a record high evaporation rate of 2.04 kg m⁻² h⁻¹ and an apparent energy conversion efficiency of 127.8% under one-sun illumination. The inherent structure not only enables sufficient water transportation, but also offers a high light-to-heat conversion efficiency originating from the carbonized surface. Furthermore, the excellent durability and environmental stability of the biochar allow for convenient recycling programs and practical applications.