Nanomaterial Design for Efficient Solar-Driven Steam Generation

Abstract

Solar-driven evaporation of water is a simple and “green” way to achieve fresh water and water purification, yet evaporation of bulk liquid using solar energy is rather low in efficiency and may require a costly optical concentration system. Recently, the technology has been rejuvenated by advanced nanomaterials for localized solar heating and rapid evaporation in a confined environment. Design of innovative nanomaterials enables solar-driven vapor generation featured with direct utilization of solar energy with no additional energy input, minimized heat loss, high efficiency, and structural flexibility, as well as potential scalable production. Controlled micro-/nanostructures of broadband photothermal nanomaterials, as well as the macroscopic assembly of desired components, are essential for these next-generation solar-driven vapor generation systems. In this work, the recent advances in design and assembly of nanomaterials/structures for optimal solar-driven vapor generation are reviewed. The design/preparation strategies, working mechanisms, and performance of the solar-driven vapor generation based on these nanomaterials are discussed. Strategies for further optimization of materials/structures for solar absorption, heat management, and water transport are summarized for solar-driven vapor generation. This contribution concludes with comments on challenges and future opportunities in the field.

Wood-Based Solar Interface Evaporation Device with Self-Desalting and High Antibacterial Activity for Efficient Solar Steam Generation

“…However, the solar evaporation efficiency of a natural photothermal system is too low to face its actual demand due to the poor solar absorption of water and its dramatic heat loss. To solve this problem, various research groups tried to develop an interfacial evaporation system based on solar absorber materials that can allow accurate localization of heat at the solar steam generation interface and reduce the bulk heat loss, thereby greatly improving solar evaporation efficiency. − …”

Hierarchical MnO2 Nanosheets Grown on Cotton Fabric as a Flexible and Washable Solar Evaporator for Seawater Desalination

“…Thermal distillation technologies and reverse osmosis membranes as traditional desalination and wastewater purification strategies need high costs and consume great quantities of energy, which limit the largescale applications and exacerbate the energy crisis. , Solar energy, one of the richest, green, and environmentally friendly energy resources, is freely available on earth. Therefore, many expectations have been placed on solar-driven desalination technology to mitigate the energy crisis and relieve the freshwater shortage. − To realize this goal, two key points of designing solar-driven steam devices should be considered, which are how to manufacture highly efficient photothermal materials and how to avoid heat loss during solar evaporation.…”

An Easy‐to‐Fabricate 2.5D Evaporator for Efficient Solar Desalination

“…To date, a substantial amount of studies have been performed which focus on achieving highly efficient evaporation rate and photothermal conversion efficiency within solar-driven steam generation. [4][5][6] There are several design factors that have been considered to significantly raise the effectiveness of 2D evaporator designs, including using photothermal materials with broadband optical absorption, [7,8] minimizing heat loss to the water sink and ambient environment, [9] and implementing an efficient water transport path. [10,11] More recently, a flood of 3D evaporator designs have exhibited evaporation performance far exceeding the theoretical limit regarding to 2D structure designs, because 3D structures allow for a reduction of diffuse reflection and heat loss, [12][13][14] a large expansion of the evaporation surface area, [15][16][17] and utilization of side areas which obtain energy from the ambient surroundings.…”