Sustainable and efficient reduction of pollutants by immobilized PEG-P/Ag/Ag2O/Ag3PO4/TiO2 photocatalyst for purification of saline wastewater

In this study, we have reported an efficient and stable degradation of pollutants at salinity condition using newly developed solar-light-driven silicone-TiO₂ based photocatalytic immobilized system. The interfacial layer of Silicone-PEG-P/Ag/Ag₂O/Ag₃PO₄/TiO₂ (S-PEG/PAgT) photocatalyst exhibited higher surface roughness, hydrophobicity, better light absorption, and narrow band gap than S-TiO₂. The Rh B degradation by S-PEG/PAgT (91.2%) was 1.71 folds higher than S-TiO₂ (53.5%) under simulated solar light irradiation. The reduction rate was significantly higher in S-PEG/PAgT (0.0792 min^-1) than S-TiO₂ (0.0229 min^-1). The S-PEG/PAgT demonstrated high TOC removal (>80%), high repeatability (10 cycles) and excellent activity after 30 days of incubation in aqueous NaCl. The mechanism analysis revealed the synergistic effect of surface morphology with irregular chamfered edges and photoinduced reactive species (O₂^-) with successive formation of free chlorine radicals (Cl) contributed to the removal of pollutants in saline wastewater. Therefore, considering the above advantages of high efficiency and effective elimination of organics illustrates the potential of newly developed S-PEG/PAgT immobilized system in long-term practical treatment real seawater and ballast water.

Totally Waterborne, Nonfluorinated, Mechanically Robust, and Self-Healing Superhydrophobic Coatings for Actual Anti-Icing

Bioinspired superhydrophobic coatings are of great interest in academic and industrial areas. However, their real-world applications are hindered by some main bottlenecks, especially the pollutive preparation methods (e.g., organic solvents and fluorinated compounds) and poor mechanical stability. Here, we report for the first time the totally waterborne, nonfluorinated, mechanically robust, and self-healing superhydrophobic coatings. The coatings were fabricated by spray-coating polyurethane (PU) aqueous solution and a hexadecyl polysiloxane-modified SiO₂ (SiO₂@HD-POS) aqueous suspension onto substrates using PU as the adhesive. The SiO₂@HD-POS suspension was synthesized by HCl-catalyzed reactions among hexadecyltrimethoxysilane, tetraethoxysilane, and SiO₂ nanoparticles. Besides high superhydrophobicity, the coatings exhibit exceptional mechanical stability against sandpaper abrasion for 200 cycles at 9.8 kPa and tape-peeling for 200 cycles at 90.5 kPa because of high durability and unique hierarchical macro-/nanostructure of the coating as well as solid lubrication of the SiO₂@HD-POS nanoparticles fallen off from the coatings. The coatings also show fast and stable self-healing capability owing to migration of the healing agent (HD-POS) to the damaged surface. Moreover, the coatings exhibit good static and dynamic anti-icing performance in outdoor environment (-15 °C, relative humidity = 54%). The superhydrophobic coatings may be used in various areas because the main bottlenecks have been successfully broken.

Recent Progress in Fabrication and Applications of Superhydrophobic Coating on Cellulose-Based Substrates

Multifuntional fabrics with special wettability have attracted a lot of interest in both fundamental research and industry applications over the last two decades. In this review, recent progress of various kinds of approaches and strategies to construct super-antiwetting coating on cellulose-based substrates (fabrics and paper) has been discussed in detail. We focus on the significant applications related to artificial superhydrophobic fabrics with special wettability and controllable adhesion, e.g., oil-water separation, self-cleaning, asymmetric/anisotropic wetting for microfluidic manipulation, air/liquid directional gating, and micro-template for patterning. In addition to the anti-wetting properties and promising applications, particular attention is paid to coating durability and other incorporated functionalities, e.g., air permeability, UV-shielding, photocatalytic self-cleaning, self-healing and patterned antiwetting properties. Finally, the existing difficulties and future prospects of this traditional and developing field are briefly proposed and discussed.

“Lotus-effect” tape: imparting superhydrophobicity to solid materials with an electrospun Janus composite mat

Lotus-effect tape: a superhydrophobic surface was easily constructed by thermally taping an electrospun Janus composite mat onto various substrates.

TiO2 nanofibers resembling ‘yellow bristle grass’ in morphology by a soft chemical transformation

We synthesized a uniquely shaped one-dimensional (1-D) TiO₂ nanostructure having the morphology of yellow bristle grass with high surface area by the titanate route under mild reaction conditions.