Environmentally Friendly in Situ Regeneration of Graphene Aerogel as a Model Conductive Adsorbent

Abstract

Adsorption is a classical process widely used in industry and environmental protection, and the regeneration of exhausted adsorbents, as the reverse process of adsorption, is vital to achieving a sustainable adsorption process. Chemical and thermal regeneration, which feature high costs and environmental side effects, are classical but not environmentally friendly methods. Herein, a new regeneration method based on an electrochemical process using graphene aerogel (GA) as a model conductive adsorbent was proposed. First, 3D GA was prepared to adsorb organic and inorganic pollutants, avoiding the inconvenience of using powdered graphene. Then, the exhausted GA was cleaned by the electrochemical desorption and degradation of adsorbed organic pollutants if undesired and the electrorepulsion of adsorbed metal ions in the absence of any additional chemicals, showing a high processing capability of 1.21 L g GA h and low energy consumption (∼0.2 kWh m solution). The mechanisms involved in the electrochemistry-induced desorption process cover a decline in the GA adsorption performance depended on the electrochemically adjustable surface charge conditions, and the further repulsion and migration of adsorbates is subject to the strong in situ electric field. This work has important implications for the development of environmentally friendly regeneration processes and qualified adsorbents as well as the application of a green and efficient regeneration concept for traditional adsorption processes.

A Sustainable Graphene Aerogel Capable of the Adsorptive Elimination of Biogenic Amines and Bacteria from Soy Sauce and Highly Efficient Cell Proliferation

“…In this respect, three-dimensional (3D) carbon nanostructures offer more efficient and preferential adsorption characteristics because of their unique characteristics, including high surface area, tunable surface chemistry, high porosity, and ultralow density . Graphene aerogels (GAs) enable fast mass transport due to excellent intrinsic properties and are highly preferred due to their advanced adsorption performance . GAs as adsorbents have shown their versatility as pollutant absorbers for the removal of dyes, formaldehyde, and other environmental toxins; on membranes for separating oil-in-water emulsion; and for efficient air filtration .…”

“…11 Graphene aerogels (GAs) enable fast mass transport due to excellent intrinsic properties and are highly preferred due to their advanced adsorption performance. 12 GAs as adsorbents have shown their versatility as pollutant absorbers for the removal of dyes, formaldehyde, and other environmental toxins; on membranes for separating oil-in-water emulsion; 13 and for efficient air filtration. 14 However, the application of greensynthesized bioinspired nontoxic GAs for fermented food safety sector in real food products has still not been emphasized enough.…”

Multifunctional Piezoelectric Heterostructure of BaTiO3@Graphene: Decomplexation of Cu-EDTA and Recovery of Cu

“…The results show that the degradation efficiency of Cu-EDTA was up to 78.1% (Figure c). BaTiO 3 @G can be regenerated by 0.1 M HCl solution with Cu recovery; in addition, BaTiO 3 @G can also be environmentally friendly regenerated by electrochemical method …”

“…BaTiO 3 @G can be regenerated by 0.1 M HCl solution with Cu recovery; in addition, BaTiO 3 @G can also be environmentally friendly regenerated by electrochemical method. 50 In conclusion, a multifunctional composite of BaTiO 3 @G was synthesized to remove and recover heavy metal complexes, which enabled decomplexation of Cu-EDTA by piezoelectric catalysis of BaTiO 3 and recovery of Cu(II) ions by in situ adsorption on graphene. This is a promising solution that does not require any traditional oxidants or precipitants and overcomes the drawbacks of traditional methods with oxidative decomplexation and precipitation.…”

Two-dimensional material-based functional aerogels for treating hazards in the environment: synthesis, functional tailoring, applications, and sustainability analysis

“…9 In addition, BN is easy to collect and reuse, showing great potential as a precursor material for the synthesis of adsorbents. However, 2DMs have some defects for the treatment of pollutants, such as easy stacking of graphene, 10 poor adsorption ability of TMD/TMO and CN, 11 high hydrophilicity of MXene that is not conducive to oil-water separation, 12 difficulty on forming of BN, 13 and others.…”