Tailoring of a Piezo‐Photo‐Thermal Solar Evaporator for Simultaneous Steam and Power Generation

Abstract

Water and electricity shortages constitute a global energy crisis that cannot be ignored. The sun is an unlimited source of energy, and oceans provide abundant water and renewable energy resources. In this study, poly-(vinylidene fluoride) (PVDF)/graphene solar evaporator membranes are fabricated for simultaneous freshwater production and power generation. Graphene addition transformed the PVDF crystal from the α-phase to the piezoelectric self-assembly β-phase. The resulting membrane is used to convert the mechanical energy of waves to electrical energy. The membrane has an output voltage of 2.6 V (±1.3 V) and an energy density of 2.11 Wm −2 for 1 Hz simulated waves, which are higher than values reported in the literature. The stacked graphene and polymer formed a wood-lumens-like mesoporous structure with a photothermal effect. Under one sun illumination, the water production rate is 1.2 kg m −2 h −1 , and the solar-thermal energy conversion efficiency is 84%. Finally, a prototype is built to prove a single evaporator's feasibility that can simultaneously obtain freshwater and generate electricity. Thus, this membrane serves as an ocean wave power generation device that can provide all-weather energy generation, convert stored electrical energy into thermal energy at night and on cloudy days, and continuously provide safe drinking water.

Engineering Hydrogels for Efficient Solar Desalination and Water Purification

“…64,65 Furthermore, realizing vapor and electricity generation at the same time becomes an interesting research direction as researchers have demonstrated electricity production induced by evaporation, 66 steam enthalpy, 67 salinity, 68 and wave energy. 69 With more possibilities of integrating advanced functional materials and expanding design principles and strategies, the broader impact of hydrogel materials in the energy−water nexus is expected to increase in importance for years to come.…”

“…Other than seawater, humid air is also a reliable water source. The sorption and releasing of water in hydrogel materials, as well as their water content, are in a highly tailorable manner, allowing higher moisture uptake capacity compared to hygroscopic salts or porous particles. , Furthermore, realizing vapor and electricity generation at the same time becomes an interesting research direction as researchers have demonstrated electricity production induced by evaporation, steam enthalpy, salinity, and wave energy . With more possibilities of integrating advanced functional materials and expanding design principles and strategies, the broader impact of hydrogel materials in the energy–water nexus is expected to increase in importance for years to come.…”

Solar-Driven Soil Remediation along with the Generation of Water Vapor and Electricity

“…Solar-driven interfacial evaporation can induce water molecules to generate electricity while desalinating. Thus, hybrid systems combining solar desalination and electricity generation have shown the potential of solar water evaporation technology for freshwater and green energy production in recent years [ 28 , 29 , 30 , 31 , 32 ]. However, as most photothermal materials are non-renewable products currently, the development of natural alternatives has gained increasing momentum in recent years [ 33 ].…”

High-Performance Solar Steam Generator Based on Polypyrrole-Coated Fabric via 3D Macro- and Microstructure Design

“…One of the most pressing global issues puzzling people is insufficient access to freshwater due to the rapid population growth and increasing water pollution. − Solar-driven water evaporation has been regarded as a highly promising technology to generate clean water due to the abundance and environmental friendliness of solar energy resources. − Therefore, significant attention has been paid to the development of high-efficiency solar vapor generators through designing smart structures and choosing advanced materials. , Consequently, it is necessary to enhance the solar absorption and conversion and heat localization and management of photothermal materials. Over the past several years, solar steam generation has achieved major breakthroughs in improving the energy utilization efficiency, depending on managing the heat loss and improving the solar absorption and conversion. − …”