High-Porosity Lamellar Films Prepared by a Multistage Assembly Strategy for Efficient Photothermal Water Evaporation and Power Generation

Abstract

The frame structure combined with water-and heattransfer capabilities fully satisfies the requirements of photothermal conversion materials in seawater evaporation applications. Meanwhile, it must integrate the characteristics of a high photothermal conversion rate, thermal management, and water transportation. Herein, lamellar porous films were successfully designed and synthesized by a simple ultrasonic-assisted vacuum filtration method. In this process, polystyrene sulfonate@carbon nanotubes/reduced graphene oxide (PSS@CNT/rGO) lamellar films were constructed by the one-dimensional synthesis of PSS@CNT self-assembled at the molecular scale and the two-dimensional matrix material rGO. It is worth noting that the lamellar film exhibits a high specific surface area (285.5 m 2 •g −1 ), which is reflected in its abundant nanopores. Among them, the porous network system composed of nanochannels can provide efficient water supply and steam-transfer ability and strengthen the heat insulation performance of thermal localization, which is beneficial to photothermal evaporation. The obtained PSS@CNT/rGO lamellar films achieved a condensed water yield of 1.825 kg•m −2 •h −1 under 1 sun illumination (1 kW•m −2 ), and their solar-vapor conversion efficiency was 97.1%. Simultaneously, the interaction between the water flow and the carbon material interface was also used to generate additional electric energy output. The maximum open-circuit voltage of 0.46 V was generated at both termini of the PSS@ CNT/rGO lamellar film, which successfully realized the multieffect utilization of energy. These results show that the multistage assembly strategy is a facile and effective means for the development of an efficient evaporation photothermal film, which offers significant value in the field of photothermal seawater evaporation and power generation.

Advances and Challenges for Hydrovoltaic Intelligence

“…With the rapid development of nanotechnology, small devices based on nanomaterials have been fabricated for electricity generation. To date, the selection of nanomaterials for power capturing via evaporation has been extended from nanostructured carbon materials − to polymer-based materials, − nano biomaterials, metallic oxide nanomaterials, − etc . This section shows the device structure and performance tests of different functional materials, indicating that the choice of materials is moving toward pluralistic systems.…”

“One stone two birds” or “you can't have your cake and eat it too”? Effects of device dimensions and position of the thermoelectric module on simultaneous solar-driven water evaporation and thermoelectric generation

“…1,2 To solve the shortage of water and electrical energy, several technologies have been developed and applied, including reverse osmosis, 3 triboelectric nanogenerators, 1 flat-panel solar TE generation 4 and WE-induced electricity generation. 2,5,6 Solar energy has become a promising energy source to replace traditional energy, attracting significant attention. Among the various solar energy utilization technologies, solar-driven photothermal conversion is used to meet the demands of various evolving applications, such as solar-driven WE and desalination 7–9 and electricity generation.…”

“…Among the various solar energy utilization technologies, solar-driven photothermal conversion is used to meet the demands of various evolving applications, such as solar-driven WE and desalination [7][8][9] and electricity generation. 2,5,6 For photothermal conversion WE, early approaches to improve PCE focused on optimizing PCMs with excellent solar absorption performances. [10][11][12][13] However, a bottleneck in efficiency has been reached using material development alone owing to the heat losses caused by thermal convection, conduction and radiation.…”

Three-Dimensional Mirror-Assisted and Concave Pyramid-Shaped Solar–Thermal Steam Generator for Highly Efficient and Stable Water Evaporation and Brine Desalination

“…Solar–thermal conversion materials are the core component in solar steam generators. The past decade has witnessed the development of novel solar–thermal materials for solar-driven evaporation applications, including noble metals, − carbon materials, − semiconducting materials, , and conjugated polymers. , Although these materials can deliver favorable absorption capability over the full solar spectrum and provide high light-to-heat efficiency for water evaporation, the structural design of evaporation systems is crucial for fully utilizing the solar absorption and solar–thermal conversion of the materials and approaching or exceeding theoretical evaporation performances. Compared to conventional two-dimensional (2D) solar-driven evaporators with planar configurations, three-dimensional (3D) solar evaporation systems are more effective in improving the solar steam generation performance.…”