Polydopamine-Bi2WO6-Decorated Gauzes as Dual-Functional Membranes for Solar Steam Generation and Photocatalytic Degradation Applications

Photothermal Material-Based Solar-Driven Cogeneration of Water and Electricity: An Efficient and Promising Technology

With the increasing demand for fresh-water and electricity in modern society, various technologies are being explored to obtain fresh-water and electricity. Due to advances in materials science, solar-driven interfacial evaporation (SDIE) systems have attracted widespread attention because they require only solar energy, and possess a high evaporation rate and little pollution. The researchers combined energy harvesting measures into the system to output electricity, further improving energy utilization. However, more in-depth research and review remain on using SDIE systems for efficient water-electricity cogeneration. Therefore, the mechanisms of different photothermal materials that utilize solar energy to produce thermal energy are first summarized in this paper. Subsequently, the mechanism and application of thermal, mechanical, chemical, and evaporation energy to produce electrical power in SDIE water-electricity cogeneration systems are discussed. Concurrently, vital mathematical equations and widely used mathematical simulation methods for performance evaluation and practical applications are presented. The design and operation of water-electricity cogeneration systems based on photothermal materials are analyzed and summarized. Based on a review and in-depth understanding of these aspects, the future development direction of cogeneration is proposed to address the problems faced in basic research and practical applications.

A Sandwich Structure Ag/MgFe2O4-Deposited Surface Carbonized Wood for Integrated Solar Steam Generation and Photoreduction of Cr(VI)

The severe deterioration of the marine ecosystem significantly negatively impacts the performance of solar-driven steam generation (SSG) and the quality of the obtained freshwater. Herein, a bifunctional Ag/MgFe2O4@SCW reactor with a sandwich structure is designed for efficient SSG and Cr(VI) reduction, which is constructed via in situ deposit Ag nanoparticles (NPs) and MgFe2O4 onto surface carbonized wood (SCW). Owing to the advanced sandwich structure and strong interfacial interactions between each component, an ultra-high evaporation rate of 1.55 kg m-2 h-1 and the efficiency of 88.6% are achieved using Ag/MgFe2O4@SCW under 1 sun. The system exhibits the long-term evaporation performance in the simulated sewage and strong acid/base solutions along with water-harvesting capacity in outdoor solar desalination. The quality of distilled water after desalination of actual seawater and NaCl solutions with different concentrations meets the WHO-recommended drinkable water standards. Furthermore, Ag/MgFe2O4@SCW shows outstanding antibacterial property, self-desalting capacity, as well as reusability and structure stability. Most importantly, the fast carrier separation endows Ag/MgFe2O4@SCW with superior photocatalytic activity and Cr(VI) photoreduction of up to 96.1% after 180 min of illumination. The bifunctional Ag/MgFe2O4@SCW reactor provides an advanced synergistic mechanism for improving SSG and photocatalytic performance, while being promising for solar-powered production of clean water.

Conjugated photothermal materials and structure design for solar steam generation

With the development of solar steam generation (SSG) for clean water production, conjugated photothermal materials (PTMs) have attracted significant interest because of their advantages over metallic and inorganic PTMs in terms of high light absorption, designable molecular structures, flexible morphology, and solution processability. We review here the recent progress in solar steam generation devices based on conjugated organic materials. Conjugated organic materials are processed into fibers, membranes, and porous structures. Therefore, nanostructure design based on the concept of nanoarchitectonics is crucial to achieve high SSG efficiency. We discuss the considerations for designing SSG absorbers and describe commonly used conjugated organic materials and structural designs.