05604nas a2200241 4500008004100000245014700041210006900188260000800257300001600265490000600281520472900287100002105016700002005037700001905057700003005076700002605106700002505132700001805157700001705175700002605192700001705218856012705235 2021 eng d00aHydrophilic 3D interconnected network of bacterial nanocellulose/black titania photothermal foams as an efficient interfacial solar evaporator0 aHydrophilic 3D interconnected network of bacterial nanocellulose cAPR a4373–43830 v43 a

The design and development of scalable, efficient photothermal evaporator systems that reduce microplastic pollution are highly desirable. Herein, a sustainable bacterial nanocellulose (BNC)-based self-floating bilayer photothermal foam (PTFb) is designed that eases the effective confinement of solar light for efficient freshwater production via interfacial heating. The sandwich nanoarchitectured porous bilayer solar evaporator consists of a top solar-harvesting blackbody layer composed of broad-spectrum active black titania (BT) nanoparticles embedded in the BNC matrix and a thick bottom layer of pristine BNC for agile thermal management, the efficient wicking of bulk water, and staying afloat. A decisive advantage of the BNC network is that it enables the fabrication of a lightweight photothermal foam with reduced thermal conductivity and high wet strength. Additionally, the hydrophilic three-dimensional (3D) interconnected porous network of BNC contributes to the fast evaporation of water under ambient solar conditions with reduced vaporization enthalpy by virtue of intermediated water generated via a BNC–water interaction. The fabricated PTFb is found to yield a water evaporation efficiency of 84.3% (under 1054 W m–2) with 4 wt % BT loading. Furthermore, scalable PTFb realized a water production rate of 1.26 L m–2 h–1 under real-time conditions. The developed eco-friendly BNC-supported BT foams could be used in applications such as solar desalination, contaminated water purification, extraction of water from moisture, etc., and thus could address one of the major present-day global concerns of drinking water scarcity.

1 aNabeela, Kallayi1 aThorat, Meghana1 aSumina, N., B.1 aRamachandran, Animesh, M.1 aThomas, Reny, Thankam1 aPreethikumar, Gopika1 aMohamed, Peer1 aAsok, Adersh1 aDastager, Syed, Gulam1 aPillai, Saju uhttps://library.ncl.res.in/content/hydrophilic-3d-interconnected-network-bacterial-nanocelluloseblack-titania-photothermal