Porous Photothermal Materials for Leveraging the Interfacial Solar Steam Generation Process

Abstract Interfacial solar steam generation (ISSG) is a promising technique that integrates the two abundant and natural sources, water and solar energy, to generate potable water using photothermal materials (PTMs). Substantial advancements have been made in accelerating steam generation from saline and wastewater resources. However, for the real-time implementation of ISSG-based desalination plants, a long journey still needs to address several challenges related to material selection and fabrication, design of ISSG device, and other factors. This work explores the advantages of using porous PTMs to enhance the overall performance of ISSG systems. It clarifies the fundamental role of porosity and porous PTMs in effective light absorption, heat distribution, and water transportation at the interface of evaporation. The study highlights the interaction of incident solar flux with porous materials, leading to enhanced hydrophilicity due to improved water transportation through porous channels, as well as porosity-dependent heat distribution and confinement. Furthermore, an extensive literature review presents the strategies and efforts made by the desalination community to fabricate nature-derived, organic/inorganic, and waste-derived porous PTMs. The highest evaporation rate of ~11.73 kg m−2 h−1 is reported for wood-derived carbon-based PTMs and Fe3O4 NPs have demonstrated efficient stability in high saline concentration of (26.47 wt%). Finally, a concise conclusion and future directives provide guidance for future research and application in this field.