Fully Lignocellulosic Biomass‐Based Double‐Layered Porous Hydrogel for Efficient Solar Steam Generation

Abstract

Solar-driven interfacial evaporation is an important approach for solving the issue of freshwater scarcity. However, the practical application of solar steam generation is hindered by high fabrication cost and environmental concerns regarding the petroleum-based materials. Herein, lignocellulose (celluloselignin composite) hydrogel (LCG) and lignin-derived carbon (LC) are used as the substrate and photothermal material, respectively, to construct a fully lignocellulose-based double-layered hydrogel (LC@LCG) evaporator. Results indicate that LC has an ultrahigh specific surface area and full-spectrum solar absorption of 98%. The presence of lignin can improve the hydrophilicity and maintain the capillary channels of the hydrogel, which tunes water into an intermediate state and reduces the vaporization enthalpy of water. Moreover, it ensures a high water transport rate in the hydrogel. Based on these advantages, the evaporation rate and photothermal conversion efficiency of hydrogel evaporator reach 1.84 kg m −2 h −1 under one sun and 86.5%, respectively. The lignocellulosic hydrogel evaporator could remove >99.95% of primary metal ions from seawater to generate fresh water, and shows outstanding salt resistance, durability, and long-term stability for desalination. This study demonstrates an eco-friendly and economic solution for continuous freshwater production from seawater using a fully lignocellulosic biomass-based hydrogel evaporator.

Robust, Scalable, and Cost-Effective Surface Carbonized Pulp Foam for Highly Efficient Solar Steam Generation

“…I is the incident illumination power density (kW m –2 ). Notably, the solar-driven evaporative capabilities of our CPNR evaporator were measured at room temperature of 20 °C and a relative humidity of 40% to eliminate the effect of environment. , …”

“…Notably, the solar-driven evaporative capabilities of our CPNR evaporator were measured at room temperature of 20 °C and a relative humidity of 40% to eliminate the effect of environment. 56,57 Calculation of the Cost-Effectiveness. The cost-effectiveness (ε) of the evaporator was defined as the evaporation rate that indicates how many kilograms of purified water can be received in 1 h for 1 US dollar spent on the materials of the evaporator.…”

Recent advances in interfacial solar vapor generation: clean water production and beyond

“…71 However, an extremely high evaporation rate is achieved in many hydrogel-based ISVG systems, which is intrinsically counter-intuitive. 73 One reasonable explanation proposed by Yu's group is that the hydrogel enables part of water molecules to be in an intermediate state, in which water evaporates with less energy than in a free state (namely reducing vaporization enthalpy). 12 In addition, numerous natural materials have been harnessed as effective substrates for ISVG systems without complicated treatment processes, representing a promising route for making sustainable, and environmentally friendly substrates.…”

Pyrene-Functionalized Alkali Lignin to Disperse Hydroxylated Boron Nitride Nanosheets in Cellulose Nanofibers for Thermal Management

“…It shows a bionic wood-like structure and a noncovalent interface interaction between BNNS and AL-PPBA was achieved, resulting in a high λ and relatively superior mechanical properties. Moreover, due to the advantages of low cost and environmental friendliness, biomass macromolecules (such as lignin, cellulose, hemicellulose, and chitosan) are used to replace the petroleum-based materials in the field of thermal conduction. − As a result, a bionic wood-like film with high λ was first synthesized, which was low-budget and environment-friendly. The functional lignin, which can be conjugated with BNNS through a noncovalent bond, is synthesized by lignin, 3-aminopropyltriethoxysilane, and 1-pyrenebutyric acid functionalization.…”