Comparative effect of mesoporous carbon doping on the adsorption of pharmaceutical drugs in water: Theoretical calculations and mechanism study

Hybrid activated carbon/ maltodextrin-functionalized fibrous silica for acetaminophen and amoxicillin adsorption: Advanced statistical physics modelling

A novel hybrid adsorbent of activated carbon/maltodextrin-functionalized fibrous silica (AC/KCC-1/DEX) was prepared for the efficient removal of Acetaminophen (ACE) and Amoxicillin (AMOX) from water. Comprehensive characterization via FESEM, TEM, BET, XPS, and FTIR confirmed an enhances surface properties and functional corporation from supporting materials and functionalization agent. Particularly, despite significant decrease in surface area upon DEX functionalization, a remarkable enhancement in adsorption removal efficiency was observed, underscoring the pivotal role of surface chemistry over surface area alone. The AC/KCC-1/DEX exhibited 87.64 m2/g and 122.94 m2/g of micropore and mesopores surface area, respectively, along with reactive functional group of DEX such as -OH, which increase surface polarity and enables strong interactions with polar pharmaceuticals. This innovative material evinced high adsorption capacity of 87.97 mg/g and 77.31 mg/g for ACE and AMOX, respectively, achieving percentage removal of 94 % and 81 %, correspondingly. Adsorption kinetics were best described by the Elovich model, suggesting heterogenous surface interactions, while Redlich-Peterson isotherm favoured physisorption. Advanced statistical physics modelling with key steric parameters provided further mechanistic insights at a molecular level, revealing a multilayer physisorption mechanism with additional chemisorption contributions. Thermodynamic analysis supported the spontaneity and exothermic nature of the process, with negative Gibbs free energy (ΔG) and enthalpy (ΔH) values, while a negative entropy change (ΔS), proposed increased order at the solid-liquid interface, indicative of strong adsorbate-adsorbent affinity and potential chemisorption effects. This study not only demonstrates the effectiveness and adsorption behaviour of AC/KCC-1/DEX but also opens new avenues for sustainable water treatment solutions.

Sonocatalytic Activity of Porous Carbonaceous Materials for the Selective Oxidation of 4-Hydroxy-3,5-dimethoxybenzyl Alcohol

Selective oxidation, which is crucial in diverse chemical industries, transforms harmful chemicals into valuable compounds. Heterogeneous sonocatalysis, an emerging sustainable approach, urges in-depth exploration. In this work, we investigated N-doped or non-doped carbonaceous materials as alternatives to scarce, economically sensitive metal-based catalysts. Having synthesized diverse carbons using a hard-template technique, we subjected them to sonication at frequencies of 22, 100, 500, and 800 kHz with a 50% amplitude. Sonochemical reaction catalytic tests considerably increased the catalytic activity of C-meso (non-doped mesoporous carbon material). The scavenger test showed a radical formation when this catalyst was used. N-doped carbons did not show adequate and consistent sonoactivity for the selective oxidation of 4-Hydroxy-3,5 dimethoxybenzyl alcohol in comparison with control conditions without sonication, which might be associated with an acid-base interaction between the catalysts and the substrate and sonoactivity prohibition by piridinic nitrogen in N-doped catalysts.

Enhanced peroxymonosulfate activation via heteroatomic doping defects of pyridinic and pyrrolic N in 2D N‑doped carbon nanosheets for BPA degradation

Understanding the role of intrinsic defects and nonmetallic heteroatom doping defects in activating peroxymonosulfate (PMS) and subsequently degrading endocrine-disrupting compounds is crucial for designing more efficient carbon catalysts. Therefore, we synthesized N-rich carbon nanosheets (NCs) through pyrolysis of a glutamic acid and melamine mixture and utilized them to activate PMS for bisphenol A (BPA) degradation. Different weight ratios of the above mixtures were allowed for manipulating NCs' defect level and N configuration. The reaction rate constant (k) was significantly positively correlated with the pyridinic and pyrrolic N content, and negatively and weakly positively correlated with graphite N and intrinsic defects, respectively. These findings suggest pyridinic and pyrrolic N, rather than graphitic N and intrinsic defects, enhance PMS activation to generate reactive oxygen species (specifically O•-2 and 1O2) and oxidize BPA. The NC-activated PMS system with the highest N content (17.9 atom%) demonstrated a remarkably high k (0.127 min-1) using minimal concentrations of PMS (0.4 mM) and NC (0.15 g/L), highlighting the system's efficiency. Excess halide anions led to significantly increased k with only a limited formation of trichloromethane (disinfection byproducts) in presence of 100 mM Cl-. This study offers novel perspectives on identifying catalytic sites within N-doped carbonaceous materials.