Carbonized Ganoderma for Ultrahigh Solar Vapor Generation

Abstract

Solar energy utilization in the interfacial evaporation has achieved near-perfect efficiency, close to its theoretical maximum. Herein, we further enhance the solar evaporation rate by harnessing the abundant ambient heat through exquisite structural design. We demonstrate that Carbonized Ganoderma (CG) exhibits an evaporation rate of 4.9 kg m⁻² h⁻¹ with a 94% solar–to–steam efficiency under one sun irradiation. This ultrahigh evaporation is achieved by efficient absorbance of ambient heat, which is significantly larger than solar energy. The CG, characterized by a natural hierarchical microstructure with high specific surface area and permeability, maximizes the utilization of ambient heat. Furthermore, our quantitative analysis reveals that ambient heat plays a dominant role in driving evaporation, especially for such high evaporation rate far exceeding the thermodynamic limit of 1.48 kg m⁻² h⁻¹. Our work proposes a general approach that effectively harvests ambient energy for ultrahigh water evaporation, employing hierarchical porous structures with high permeability.