Cellulose paper support with dual-layered nano–microstructures for enhanced plasmonic photothermal heating and solar vapor generation

Abstract

Plasmonic nanoparticles, such as gold nanoparticles (AuNPs), have been actively applied in solar vapor generation for seawater desalination and water purification, owing to their photothermal heating performances. Such nanoparticles have been frequently anchored within porous supporting materials to ensure easy handling and water absorption. However, there has been limited progress in improving the transport efficiency of light to nanoparticles within porous supports to achieve more effective photothermal heating. Here, we show an enhanced light absorption of AuNPs by supporting on a cellulose paper with tailored porous structures for efficient photothermal heating. The paper consists of AuNP-anchored cellulose nanofibers and cellulose pulp as the top and bottom layers, respectively, which provides dual-layered porous nano-microstructures in the perpendicular direction. Then, the bottom layer with pulp-derived microstructures reflects the transmitted light back to AuNPs within the top layer, which improves their light absorptivity. Thus, under 1 sun illumination, the dual-layered paper demonstrates superior performance in photothermal heating (increases from 28 C to 46 C) and solar vapor generation (1.72 kg m À2 h À1 ) compared with the single-layered AuNP-anchored cellulose nanofiber paper even at the same AuNP content. Furthermore, the water evaporation rate per AuNP content of the dual-layered paper is more than 2 times higher than those of the state-of-the-art AuNPanchored porous materials under the same light irradiation. This strategy enables the efficient use of precious plasmonic nanoparticles for further development of solar vapor generation. † Electronic supplementary information (ESI) available: X-ray diffraction pattern of the AuNP@cellulose nanober paper; surface temperature of cellulose nanober paper and AuNP@cellulose nanober paper over time during surface temperature measurement under 1.0 kW m À2 irradiation; UV-vis-NIR transmittance and reectance spectra of AuNP@cellulose nanober paper and AuNP@cellulose nanober/pulp paper; UV-vis-NIR reectance spectra of pulp paper with different pulp content and absorption spectra of AuNP@cellulose nanober/pulp paper with different pulp content; surface temperature of AuNP@cellulose nanober paper and AuNP@cellulose/pulp paper over time during surface temperature measurement under 1.0 kW m À2 irradiation. See

Thermoplasmonics in Solar Energy Conversion: Materials, Nanostructured Designs, and Applications

“…[203] However, for the substrate design, the pore sizes, wettability, and density are all important factors to be considered. Artificial porous materials including carbon cloths, [175] foams, [204] aerogels, [194] polymers, [205] papers, [206] etc., and natural materials with inherent microchannels and low thermal conductivity, e.g., wood, [207] bamboo, [208] etc., have been adopted to allow for good water transport and heat localization. The latter is crucial for interfacial evaporation under low optical concentration, for which the realization necessitates four structural characteristics including absorption across the solar spectrum, thermal insulation, hydrophilic behavior, and interconnected pores.…”

Nanocellulose Paper Semiconductor with a 3D Network Structure and Its Nano–Micro–Macro Trans-Scale Design

“…Cellulose nanofibers with a width of 22 ± 8 nm and carboxylate content of 0.08 ± 0.02 mmol g –1 were prepared from never-dried pulp (softwood bleached kraft pulp) by employing the method described in our previous report. 46 First, an aqueous suspension of the pulp (0.3 wt %, 2 L) was treated using a high-pressure water-jet system equipped with a counter-collision chamber (Star Burst, HJP-25005E, Sugino Machine Co., Ltd., Uozu, Japan). The pulp suspension was ejected from a nozzle with a diameter of 0.10 mm under a high pressure of 245 MPa with 100 passes.…”

Semicarbonized Subwavelength-Nanopore-Structured Nanocellulose Paper for Applications in Solar Thermal Heating

“…The solar thermal heating performances of the carbonized nanopaper were evaluated by measuring the nanopaper surface temperatures under solar light irradiation, according to a method detailed in our previous report. 45 Prior to the temperature measurements, the emissivity of each nanopaper was evaluated using black body tape exhibiting an emissivity of 0.95 (HB-250, OPTEX Co., Ltd., Shiga, Japan) as a reference. The nanopaper and black tape were heated using a temperature controller (SBX-303, Sakaguchi E.H. VOC Corp., Tokyo, Japan) to 75 °C.…”