Biomass-Based Antibacterial Hybrid Engineering Hydrogel for Efficient Solar Steam Generation

Abstract

Interfacial solar steam generation is recognized as a promising solution to alleviate the scarcity of freshwater resources owing to its utilization of clean solar energy alongside its high efficiency and minimal heat loss. Nonetheless, the utilization of solar energy for water evaporation encounters challenges, primarily manifested in low evaporation rates and efficiency. Herein, we introduced an approach involving the development of a biomass-based hybrid engineering hydrogel evaporator, denoted as CLC (chitosan and lignosulfonate sodium hybrid hydrogel with a carbon nanotube). The construction of this evaporator involves the straightforward blending of lignosulfonate sodium (LS) and marine polysaccharide biomass chitosan (CS) with carbon nanotubes (CNT) serving as the photothermal materials. The interaction between the sulfonic group of LS and the amino group of CS with water molecules, facilitated by hydrogen bonding and electrostatic interactions, reduces the evaporation enthalpy of water, thereby lowering the energy demand for evaporation. Furthermore, the incorporation of LS reduces the thermal conductivity of the as-prepared hydrogel and promotes photothermal management to mitigate heat loss. The CLC hydrogel demonstrates an evaporation rate of 2.48 kg m^–2 h^–1 and energy efficiency of 90% under one sun illumination. Moreover, the CLC hydrogel exhibits excellent antibacterial properties (98.4%), ensuring that desalinated water meets drinking standards. This high efficiency and eco-friendly biomass hydrogel with antibiological pollution characteristics and purification abilities holds great potential for widespread application of long-term seawater desalination.