Unlocking the paracetamol adsorption mechanism in graphene tridimensional-based materials: an experimental-theoretical approach

Abstract

The omnipresence of emerging contaminants in the aquatic environment is indisputable. These contaminants include chemical substances not removed in traditional water and sewage treatment processes. To ensure the quality of water and healthy aquatic ecosystems, new treatment technologies and materials are essential to effectively control the presence of these contaminants in the aquatic environment. More than that, it is important to know how molecules interact with these new materials. A low-cost alternative currently available is adsorption. Despite this method being widely studied, describing the interaction mechanisms between the materials and the analytes is not usual, limiting the obtainment of more efficient materials. Thus, the objective of this work was to understand, in a theoretical-experimental way, the forms of interaction in the adsorption of the drug paracetamol, widely used worldwide, in materials based on graphene with different chemical and structural properties. For this, kinetic and isothermal experimental studies were carried out using four materials that contemplated different dimensions, pore sizes, and oxidation degrees. In theoretical studies, density functional theory (DFT) simulations were performed to cover quantum details, revealing how paracetamol interacts with different graphene structures. According to theoretical studies, binding energies, binding distances, and charge transfer between oxidized graphene and paracetamol drug are compatible with physical adsorption, strongly dependent on the type and number of functional groups on the graphene surface. These results agree with the experimental data where the highest adsorptions were observed precisely for materials containing a higher proportion of functional groups and where these groups are more available (more porous), with adsorptive capacities reaching 235.7 mg/g. Our findings contribute to scientific knowledge about using graphene structures as an adsorbent material, providing a solid basis for future studies and developing more efficient and advanced water treatment technologies.

Nanocarbon Dimensionality and Oxidation Degree Influence the Sorption of Atenolol: Implications for Water Treatment

“…The effect of the latter is also described in Leão et al, where the use of theoretical studies corroborates the experimental data, proving that the evaluation of the degree of compaction of the structure is essential in the application of materials in the removal of organic contaminants from aqueous solution. Similar results are described for the same materials in removing paracetamol from water . In this study, it can be observed, in the case of 3D materials, that the material that presents a less compacted structure (3D-rGO5) is also the one that can sorb more significant amounts of atenolol with a shorter equilibrium time and t 1/2 when compared to the material that presents the most compacted structure (3D-rGO25).…”

Unraveling the Phosphorus Adsorption Mechanisms in Three-dimensional Reduced Graphene Oxide Materials

“…An important point to be considered concerns the adsorptive efficiencies of 3D-rGO0 and 3D-rGO5 materials. Previous works verified that the 3D-rGO5 material has better adsorptive capacities, ,− which is not verified in this study. One explanation refers to the type of analyte investigated.…”

“…Also, this low adsorption is believed to be related to the drying method of the three-dimensional structure. This study used the materials as xerogels, with higher compaction and lower adsorptive capacities than those in a hydrogel form used in our previous studies. ,− …”