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In this study, poly(4-vinylpyridine) (P4VP) was first grafted onto the surface of halloysite nanotubes (HNTs) via in situ polymerization, and then, silver ions were immobilized on P4VP via complex reaction. Finally, silver ions were reduced to silver nanoparticles (Ag NPs). Polyethersulfone (PES) ultrafiltration membranes bending with modified HNTs loaded with Ag NPs were prepared via phase inversion. FT-IR spectra and TGA results showed that HNTs were modified successfully. The contact angle data indicated that the hydrophilicity of the membranes was enhanced by the addition of modified HNTs. The permeation properties of the hybrid membranes were significantly superior to the pure PES membrane, especially when the modified HNTs content was 3%; the pure water flux of the membrane reached the maximum at 396.5 L•m −2 •h −1 , which was about 251.5% higher than that of the pure PES membrane, and the rejection was slightly affected by the addition of the modified HNTs. The microstructure of the membranes was characterized using scanning electron microscopy (SEM) and atomic force microscopy (AFM). The results showed that the structure of membrane was not obviously affected by addition of the modified HNTs. Antibacterial activity of the hybrid membrane was evaluated with the viable cell count method using antibacterial rate against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). The antibacterial rates of the hybrid membranes against E. coli and S. aureus were about 99.9% and 99.8%, respectively.

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Hybrid asymmetric supercapacitors based on Ni0.85Se nanosheet arrays and activated carbon show remarkable energy-storage characteristics and promising applicable value.

Organized arrays of halloysite clay nanotubes have great potential in molecular separation, absorption, and biomedical applications. A highly oriented layer of halloysite on polyacrylonitrile porous membrane was prepared via a facile evaporation-induced method. Scanning electronic microscopy, surface attenuated total reflection Fourier transform infrared spectroscopy, and energy dispersive X-ray spectroscopy mapping indicated formation of the nanoarchitecture-controlled membrane. The well-ordered nanotube coating allowed for the excellent dye rejection (97.7% for reactive black 5) with high salt permeation (86.5% for aqueous NaCl), and thus these membranes were suitable for dye purification or concentration. These well-aligned nanotubes' composite membranes also showed very good fouling resistance against dye accumulation and bovine serum albumin adsorption as compared to the pristine polyacrylonitrile or membrane coated with disordered halloysite layer.

Highly selective oxidation of a single specific hydroxyl group in glycerol is attractive but challenging because glycerol contains three similar hydroxyl groups. In this work, we developed a ternary photoanode comprising Ag nanoparticle-supported layered double hydroxide (LDH) nanosheets on TiO2 (denoted Ag@LDH@TiO2) for the glycerol selective oxidation to 1,3-dihydroxyacetone via photoelectrochemical water oxidation under neutral conditions. It was proved that hydroxyl radicals generated by water oxidation were the dominating active oxygen species and oxygen atoms in the main oxidation product came from water. The LDHs and Ag nanoparticles enhanced the selectivity of secondary hydroxyl oxidation, and the Ag nanoparticles further accelerated the corresponding kinetics. The Ag@LDH@TiO2 photoanode exhibited a 1,3-dihydroxyacetone selectivity of 72% at 1.2 V vs reversible hydrogen electrode, which is obviously higher than that of pure TiO2 (23.5%) and surpasses most materials reported thus far. The role of LDHs and Ag nanoparticles in selective oxidation of glycerol was revealed through detailed spectroscopic and computational studies. Specifically, Fourier transform infrared spectroscopy analysis revealed that the middle hydroxyl group is preferentially adsorbed to LDH surfaces, while density function theory calculations verified that the surface-bound hydroxyl radicals mediated dehydrogenation barriers of middle carbon of adsorbed glycerol; the Ag nanoparticles promoted the selective adsorption of middle hydroxyl of glycerol, which further induced its selective oxidation.

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