Copper Nanoparticle Loading and F Doping of Graphene Aerogel Enhance Its Adsorption of Aqueous Perfluorooctanoic Acid

Abstract

Perfluorooctanoic acid (PFOA) persists in the environment for a long time due to its stable physical and chemical properties, and it is harmful to the environment and biological system. In order to effectively remove PFOA from aqueous solution, Cu nanoparticles and fluorine-modified graphene aerogel (Cu/F-rGA) were fabricated by the microbubble template method. Compared with unmodified aerogels (rGA), the adsorption rate of PFOA on Cu/F-rGA was enhanced 2.68-fold. These significant improvements were assumed to benefit from the ligand exchange reaction and hydrophobic and F–F interactions. The regeneration of Cu/F-rGA maintained 73.26% with ethanol as the desorption solvent after 10 times adsorption–desorption. The fitting results of the statistical physics model showed that PFOA tended to be parallel to the adsorption site at low temperature and perpendicular at high temperature. The number of PFOA molecules connected to each adsorption site was 0.53 to 1.41, and the number of adsorption layers of PFOA on the Cu/F-rGA was between 1.63 and 2.51. Compared with the response surface methodology and artificial neural network, an adaptive neuro-fuzzy inference system had more accurate analysis and prediction results. These results provide an effective and alternative strategy to remove PFOA from aqueous solution with environment-friendly consumption.

2D Fluorinated Graphene Oxide (FGO)-Polyethyleneimine (PEI) Based 3D Porous Nanoplatform for Effective Removal of Forever Toxic Chemicals, Pharmaceutical Toxins, and Waterborne Pathogens from Environmental Water Samples

“…As we have discussed before, PFAS contamination is a serious concern for society due to its association with adverse health effects such as cancer, immunity decline, and liver damage. − As a result, there is an urgent need for advanced systems that can separate PFAS from water. − Next, to determine the capturing and separating efficiency of PFBA, PFBS, PFHxS, and PFNA from environmental samples using the FGO-PEI based 3D nanoplatform, we performed the following experiments. Initially, we infected the drinking water samples with PFBA, PFBS, PFHxS, and PFNA selectively and simultaneously.…”

“…The removal efficiency (RE) for PFBA, PFBS, PFHxS, and PFNA toxic chemicals was determined using eq : − RE ( % ) = c initial − c t c initial × 100 where C initial is the concentration of PFBA, PFBS, PFHxS, or PFNA toxic chemicals before separation and C t is the concentration of PFBA, PFBS, PFHxS, or PFNA toxic chemicals at time t during the separation process. The amount of PFBA, PFBS, PFHxS, and PFNA toxic chemicals removed by GO, FGO, PEI-GO, or PEI-FGO adsorbent was determined using eq : − q t = c initial − c t c normalA where q t is the amount of PFBA, PFBS, PFHxS, and PFNA toxic chemicals absorbed separately per gram of GO, FGO, PEI-GO, or PEI-FGO at time t and C initial is the concentration of PFBA, PFBS, PFHxS, or PFNA toxic chemicals before separation.…”

“…For the determination of the removal amount of perfluorobutanoic acid (PFBA) and perfluorobutanesulfonic acid (PFBS) using the two-dimensional (2D) fluorinated graphene oxide and PEI based three-dimensional (3D) porous nanoplatform, we used LC–MS (Agilent technologies). − Details are reported in the Supporting Information.…”

“…Based on a recent report by the Environmental Protection Agency (EPA), 45% of US tap water is contaminated with forever chemicals like per- and polyfluoroalkyl substances (PFAS) . As per the EPA, the concentrations of per- and polyfluoroalkyl substances are higher than the EPA limit (70 ng L –1 ) in ground and surface water systems in 3186 locations in 50 states in the USA. − Since 2016, as per US EPA instructions, the industry has been using short-chain homologues of the long-chain PFAS. − In 2022, reported data by the US EPA indicated that the concentrations of short-chain perfluorobutanesulfonic acid (PFBS), perfluorobutanoic acid (PFBA), and tetrafluoro-heptafluoropropoxy propanoic acid (GenX) are increasing in environmental samples, which is alarming. − Several studies indicate that short- as well as long-chain PFAS can play a major role in hepatic, hematological, and renal cancer. − To tackle the PFAS contamination in water challenges, scientists are designing novel adsorbents with high affinity for per- and polyfluoroalkyl substances for PFAS removal from water. − Because C–F bonds in per- and polyfluoroalkyl substances can participate in electrostatic, hydrophobic, and fluorophilic interactions, several efforts have been devoted to design new adsorbents to remove PFAS using dipole–dipole, ionic–dipolar, and fluorophilic interactions. − However, several reported data show high removal capacity for long-chain per- and polyfluoroalkyl substances, and the removal efficiency decreased significantly for short-chain PFAS. − Herein, we have designed a 2D fluorinated graphene oxide (FGO) and polyethylenimine (PEI) based three-dimensional (3D) porous nanopla...…”

A perspective on graphene based aerogels and their environmental applications

“…An other harmful organic compound is represented by perfluorooctanoic acid (PFOA) due to its high stability and consequent not degradability. To efficiently remove PFOA Liu et al [96] functionalized GO aerogels with Cu nanoparticles and fluorine with consequent enhanced 2.68-fold respect to neat GO aerogels and high possibility to reuse them several times. The improvement is ascribed to better ligand exchange reaction and hydrophobic interactions.…”