Robust and Multifunctional 3D Graphene-Based Aerogels Reinforced by Hydroxyapatite Nanowires for Highly Efficient Organic Solvent Adsorption and Fluoride Removal

Abstract

In view of the serious perniciousness and complex diversity of actual wastewater systems, exploiting a robust and multifunctional adsorbent material featuring high sorption efficiency, broad-spectrum applicability, and excellent recyclability in treating multifarious pollutants in water (such as oils and fluoride ions) is highly required; however, it is still a daunting goal to pursue to date. In this work, novel mechanically robust and exceptional graphene oxide/hydroxyapatite nanowire (GO/HAPNW) aerogels (RGHAs/polydopamine (PDA)@RGHAs) with adjustable surface wettability were developed through a facile sol–gel self-assembly technology and subsequently optional bioinspired hydrophilic modification. Thanks to the reinforcing effect of HAPNWs with higher aspect ratio, a remarkably improved mechanical robustness (including superior compressibility and superelasticity) was acquired for the resulting aerogels. Based on the cooperative effect of the favorable selective wetting properties (i.e., hydrophobic/oleophilic for RGHAs) and the excellent mechanic stability, the aerogels displayed an outstanding sorption performance for diverse oils/organic solvents accompanied with a prominent recyclability. Specifically, a fairly high adsorption capacity of as high as 191 times of its own mass (for pump oil) was achieved based on a fast adsorption kinetic process. More importantly, superamphiphilic three-dimensional (3D) PDA@RGHAs revealed an extraordinary removal capability for water-soluble fluoride ions, exhibiting a superior equilibrium adsorption capacity (q e, 9.93 mg/g), which is distinctly superior to those of low-dimensional fluorine adsorbent materials recently reported. Accordingly, the as-prepared 3D aerogels combining both superior oil/organic solvent adsorption and excellent defluorination capability reveal a competitive application prospect toward effective intricate oily wastewater purification.

Biomimetic Aerogel with Aligned Porous Structures from Ice Templating for Water Evaporation‐Induced Electricity Generation

“…An increased I D /I G ratio of prGO after thermal reduction is commonly reported in previous studies, indicating good restoration of sp 2 carbon and/or a decrease in the average size of the sp 2 domains during the reduction process. [27][28][29] After mild thermal reduction, a small portion of the oxygen functional groups was reduced. The Fourier transform infrared spectrum (FTIR) of prGO is shown in Figure 2d.…”

High-efficiency N-doped activated carbon-based defluoridation adsorbent prepared from itaconic acid fermentation waste liquid

“…In alkaline media (7 r pH r 12), the adsorptive defluoridation capacity of PC-N decreases sharply, which is due to the deprotonation of the PC-N surface (induced by the occupation/covering of a large number of negative charges). 35 The initially dominant electrostatic attraction between PC-N and F À (in an acidic medium) has been transformed into electrostatic repulsive force (in an alkaline medium), resulting in desorption of F À from the PC-N surface, and playing a role in the regeneration of PC-N. It can also be seen from Fig.…”

Lanthanum Cerate Microspheres for Efficient Fluoride Removal from Wastewater

“…Skeletal and dental fluorosis are just two of the potential side effects of consuming water with a fluoride content. 2 The yellow gas fluorine has strong oxidizing and corrosive properties, as well as a distinct odor. People can absorb fluoride through food, drink, air, medications, and cosmetics.…”