Water pollution caused by heavy metal ions has attracted worldwide attention. In this work, gold tailings were used as raw materials and the sol–gel method combined with the atmospheric pressure drying method were used to achieve the low-cost preparation of a silica aerogel. (3-Aminopropyl) triethoxysilane (APTES), ethylenediaminetetraacetic acid disodium salt (EDTA-2Na), and chitosan were used to modify the silica aerogel, which was then used as an adsorbent for the adsorption of copper ions in wastewater. The adsorbent type, adsorption time, copper ion concentration, and pH value were investigated as variables to explore the best adsorption conditions. The adsorption mechanism was also elaborated on. The crystal structure, surface morphology, surface functional groups, chemical composition, and specific surface area of the aerogels and the modified aerogels were characterized by various physiochemical characterizations such as XRD, SEM, FT-IR, XRF, and BET. The results showed that the prepared silica aerogel contained 91.1% SiO2, mainly amorphous SiO2, and amino and carboxyl groups. Other functional groups were successfully grafted onto the silica aerogels. The original silica aerogels and modified silica aerogels had a large specific surface area, total pore volume, and pore diameter. When copper ions were adsorbed by the chitosan-modified silica aerogels, the adsorption capacity of the copper ions was the highest (33.51 mg/g) under the conditions of a copper ion concentration of 100 mg/L, a pH value of 7, and an adsorption time of 2 h. The adsorption of Cu2+ was mainly due to the ion exchange and electrostatic gravity.

In this work, a novel nanocomposite of highly-dispersed MoS2 nanosheets supported on alkali-activated halloysite nanotubes (a-HNTs) was fabricated via a simple hydrothermal method. The alkali (5 M NaOH herein) could...

Integration of nanoclay minerals into rigid polyurethane foams (RPUFs) is a cost-effective solution to enhance foam’s performance via environmental protection technology. In this work, palygorskite/RPUFs nanocomposites (Pal/RPUFNs) with excellent mechanical properties and thermal stability were prepared via a one-step method, using 4,4’-diphenylmethane diisocyanate and polyether polyol as the starting materials, coupled with Pal modified by silane coupling agent KH570. The effects of the modified Pal on the mechanics, morphology, and thermal properties of the nanocomposites were studied systematically. When the content of the modified Pal was 8 wt% of polyether polyol, the elastic modulus and compressive strength of the Pal/RPUFNs were increased by ca. 131% and 97%, respectively. The scanning electron microscopy images indicated that the addition of the modified Pal significantly decreased the cell diameter of the Pal/RPUFNs. The results of thermogravimetric and derivative thermogravimetry analyses revealed that the addition of the modified Pal increased the thermal weight loss central temperature of the Pal/RPUFNs, showing better thermal stability in comparison with the pure RPUFs. A self-made evaluation device was used to estimate the thermal insulation ability of the Pal/RPUFNs. It was found that the small cell size and uniform cellular structure were keys to improving the thermal insulation performance of the RPUFs. The prepared Pal/RPUFNs are expected to have great potential in the field of building insulation.

Pristine tungsten disulfide (WS2) nanosheets are extremely prone to agglomeration, leading to blocked active sites and the decrease of catalytic activity. In this work, highly dispersed WS2 nanosheets were fabricated via a one-step in situ solvothermal method, using sepiolite nanofibers as a functional carrier. The ammonium tetrathiotungstate was adopted as W and S precursors, and N,N-dimethylformamide could provide a neutral reaction environment. The electron microscope analysis revealed that the WS2 nanosheets were stacked compactly in the shape of irregular plates, while they were uniformly grown on the surface of sepiolite nanofibers. Meanwhile, the BET measurement confirmed that the as-prepared composite has a larger specific surface area and is more mesoporous than the pure WS2. Due to the improved dispersion of WS2 and the synergistic effect between WS2 and the mesoporous sepiolite mineral which significantly facilitated the mass transport, the WS2/sepiolite composite exhibited ca. 2.6 times the photocatalytic efficiency of the pure WS2 for rhodamine B degradation. This work provides a potential method for low-cost batch preparation of high-quality 2D materials via assembling on natural materials.