Effective Removal of Sulfonamides Using Recyclable MXene-Decorated Bismuth Ferrite Nanocomposites Prepared via Hydrothermal Method

Recent advancements on 2D nanomaterials as emerging paradigm for the adsorptive removal of microcontaminants

Water reservoirs are facing increasing prevalence of microcontaminants originating from agricultural runoff, industrial effluents, and domestic wastewater. The persistence of microcontaminants leads to disruptions in aquatic ecosystems and poses potential long-term health risks to humans, even at minimal concentrations. However, traditional wastewater treatment methods are inefficient to eliminate the microcontaminants because of their intricate chemical structures and low concentration. In this regard, nano-adsorption employing nanomaterials as adsorbents presents a viable alternative, offering enhanced efficiency and specificity towards the removal of microcontaminants. Amongst all, two-dimensional (2D) nanomaterials, including graphene oxide (GO), layered double hydroxides (LDHs), MXenes, and boron nitrides (BNs), exhibit distinctive characteristics such as a high surface area, remarkable chemical stability, and tendency of diverse surface functionalization, rendering them particularly effective in adsorbing pollutants from water. Therefore, the present review provides an exhaustive literature and comparative analysis of the aforementioned 2D nanomaterials-based adsorbents concerning their efficacy in adsorbing microcontaminants of pharmaceuticals and personal care products origin such as antibiotics, steroids, bisphenols, phthalates, parabens, and benzophenones. The different aspects of 2D adsorbents including adsorption capacity, mechanisms involved, kinetic and isotherm models followed for removal of a variety of microcontaminants have been congregated. Also, the information on recyclability, reusability, and stability of the adsorbents has been summarized to highlight their viability. Further, the limitations and future aspects related to the use of 2D nanomaterials-based adsorbents towards pollutant removal have been discussed. Overall, 2D nanomaterials holds great promise as efficient adsorbents for environmental remediation and can also be explored for industrial adsorption applications.

Streamlined fabrication of AuPtRh trimetallic nanoparticles supported on Ti3C2MXene for enhanced photocatalytic activity in cephalosporins degradation

The escalating prevalence of cephalosporin antibiotics in wastewater poses a serious threat to public health and environmental balance. Thus, it is crucial to develop effective methods for removing cephalosporin antibiotics from water sources. Herein, we propose the use of AuPtRh trimetallic nanoparticles supported on Ti3C2MXene as a photocatalyst for the degradation of cephalosporin antibiotics. Initially, AuPtRh nanoparticles were uniformly grown onto Ti3C2MXene sheets using one-step reduction technique. The prepared AuPtRh/Ti3C2MXene exhibited a complete degradation of cefixime and ceftriaxone sodium, while an impressive degradation efficiency of 91.58 % for cephalexin was achieved after 60 min of exposure to visible light, surpassing the performance of its individual AuPtRh nanoparticles and Ti3C2MXene. The enhanced photoactivity of AuPtRh/Ti3C2MXene was resulted from improved light absorption capacity and efficient generation, separation, and transfer of charge carriers driven by the formation of heterojunction between AuPtRh and Ti3C2MXene. Electron paramagnetic resonance and radicals trapping experiments results revealed that •O2- and h+ are the principal reactive species governing the degradation of cephalosporins. The photocatalyst exhibited excellent stability and could be reused four times without significant loss in efficiency. Our study highlights the potential of MXene composites for environmental remediation, offering insights into designing sustainable AuPtRh/Ti3C2MXene photocatalyst for water pollutant degradation.

Preparation and evaluation of a tryptophan based hypercrosslinked porous polymer as an efficient adsorbent for pipette tip solid-phase extraction of sulfonamides

A novel tryptophan-based porous polymer is designed and synthesized via a facile one-step hypercrosslinking polymerization process, and applied as sorbent for extraction of trace sulfonamides in foodstuffs. The developed polymer has high surface area, large conjugate system, and abundant functional groups (e.g., π-π stacking, hydrogen bonding, hydrophobic and electrostatic attraction interactions), which endow it with superior affinity and high adsorption capacity for sulfonamides (16.16-59.29 mg g-1). The optimized SPE method is coupled with HPLC-DAD to create a sensitive and efficient protocol that provides good linearity (R2 ≥ 0.9979), low limits of detection, satisfactory recoveries (92.5-109.5 %) and high precisions (RSDs < 8.24). In addition, the newly proposed method greatly reduces the amount of adsorbent (2.0 mg) and organic solvent (2.0 mL) used. Adsorption kinetics, isotherms, and simulation calculations studies further reveal the presence of monolayer adsorption, chemical adsorption process, and multiple interactions. Thus, this work presents a polymer capable of multiple interactions for the pretreatment of trace sulfonamides in foodstuffs.

MXenes as emerging adsorbents for removal of environmental pollutants

MXenes are a recently emerging class of two-dimensional nanomaterials that have gained considerable interest in the field of environmental protection. Owing to their high surface area, abundant terminal groups, and unique two-dimensional layered structures, MXenes have demonstrated high efficacy as adsorbents for various pollutants. Here we focused on the latest developments in the field of MXene-based adsorbents, including the structure and properties of MXenes, their synthesis and modification methods, and their adsorption performance and mechanisms for various pollutants. Among the pollutants that have been reported to be adsorbed by MXenes are radionuclides (U(VI), Sr(II), Cs(I), Eu(III), Ba(II), Th(IV), and Tc(VII)/Re(VII)), heavy metals (Hg(II), Cu(II), Cr(VI), and Pb(II)), dyes, per- and polyfluoroalkyl substances (PFAS), antibiotics (tetracycline, ciprofloxacin, and sulfonamides), antibiotic resistance genes (ARGs), and other contaminates. Moreover, future directions in MXene research are also suggested in this review.