Ultralong polypyrrole nanotubes aerogels with excellent elasticity for efficient solar steam generation

Vertical porous aerogel based on polypyrrole and bimetallic modified β-cyclodextrin polymer-chitosan for efficient solar evaporation

Solar-driven interfacial evaporation (SDIE) stands out as a prospective technology for freshwater production, playing a significant role in mitigating global water scarcity. Herein, a cyclodextrin polymer/chitosan composite aerogel (PPy-La/Al@CDP-CS) with vertically aligned channels was prepared as a solar evaporator for efficient solar steam generation. The vertically aligned pore structure, achieved through directional freezing assisted by liquid nitrogen, not only improves water transport during evaporation but also enhances light absorption through multiple reflections of sunlight within the pores. The polypyrrole particles sprayed on the surface of the aerogel acted as a light-absorbing layer, resulting in an impressive absorbance of 98.15 % under wetting conditions. The aerogel has an evaporation rate of 1.85 kg m-2 h-1 under 1 kW m-2 irradiation. Notably, the vertical pore structure of the aerogel allows it to exhibit excellent evaporation performance and salt resistance even in highly concentrated salt solutions. Furthermore, this aerogel is an excellent solar-driven interfacial evaporator for purifying seawater and fluoride-containing wastewater. This photothermal aerogel has the advantages of excellent performance, low cost, and environmental friendliness, and thus this work provides a new approach to the design and fabrication of solar photothermal materials for water treatment.

Highly efficient MoS2/MXene aerogel for interfacial solar steam generation and wastewater treatment

Interfacial solar steam generation using aerogels holds great promise for seawater desalination and wastewater treatment. However, to achieve aerogels with both durable, high-efficiency evaporation performance and excellent salt resistance remains challenging. Here, a molybdenum disulphide (MoS2) and MXene composite aerogel with vertical pore channels is reported, which has outstanding advantages in mechanical properties, water transportation, photothermal conversion, and recycling stability. Benefiting from the plasmon resonance effect of MXene and the excellent photothermal conversion performance of MoS2, the aerogel exhibits excellent light absorption (96.58 %). The aerogel is resistant to deformation and able to rebound after water absorption, because of the support of an ordered vertical structure. Moreover, combined with the low water evaporation enthalpy, low thermal conductivity, and super hydrophilicity, the aerogel achieves an efficient and stable evaporation rate of about 2.75 kg m-2h-1 under one sun and exhibits excellent self-cleaning ability. Notably, the evaporator achieves removal rates of 99.9 % for heavy metal ions and 100 % for organic dyes, which has great potential in applications including seawater desalination and wastewater purification.