Detection Of Adsorption Research Articles

Mechanism of adsorption and gas-sensing of hazardous gases by MoS2 monolayer decorated by Pdn (n=1–4) clusters

The adsorption behaviors of hazardous gases (NO2 and SO2) on MoS2 monolayer decorated by Pdn (n=1–4) clusters (Pdn-MoS2) are investigated by first-principles calculations, and the performance of Pdn-MoS2 gas sensors has also been studied in this work. Our results show that Pdn nanocluster can enhance the electrical conductivity of MoS2 monolayer with band gaps of Pdn-MoS2 (n=1–4) sharply decreased, and the adsorption performance of NO2 and SO2 with higher adsorption energy and larger charge transfer. Thus, Pdn-MoS2 show higher sensitive to NO2 and SO2 molecules compared with pristine MoS2. The band gaps of Pdn-MoS2 can be further decreased upon the adsorption of NO2 and SO2 (except for SO2/Pd4-MoS2), indicating Pdn-MoS2 (n=1–3) gas sensor shows improved gas-sensitive response to both NO2 and SO2, and Pd4-MoS2 shows improved gas-sensitive response only to NO2. The recovery time analysis indicates that Pdn-MoS2 (n=1–4) is applicable to be utilized as NO2 and SO2 scavenger at ambient temperature, and the recovery process can be realized simply by heating. Our results indicate that Pdn-MoS2 (n=1–4) monolayer is a favorable candidate as adsorbent for detection and removal of NO2 and SO2, and also provides guidance for further study of the MoS2 monolayer decorated by transition metal clusters.

Regenerable and Highly Stable Two-Dimensional Imine-Based Covalent Organic Framework for Simultaneous Rapid Detection and Adsorption of Cu2+ Ions.

The development of efficient fluorescent probes and adsorbents for detecting and removing Cu2+, which pose potential environmental and health risks, is a highly active area of research. However, achieving simultaneously improved fluorescence detection efficiency and enhanced adsorption capacity in a single porous probe remains a significant challenge. In this study, we successfully synthesized a two-dimensional imine-based TAP-COF using 2,4,6-triformylphloroglucinol and tri(4-aminophenyl)amine as raw materials. TAP-COF exhibited excellent properties, including a large specific surface area of 685.65 m2·g-1, exceptional thermal stability (>440 °C), chemical stability, temporal stability, and recyclability. Fluorescence testing revealed that TAP-COF exhibited remarkable specificity and high sensitivity for detecting Cu2+. The fluorescence mechanism, in which the excited state intramolecular proton transfer was impeded by the interaction of Cu2+ with C═O and C-N bonds on TAP-COF upon the addition of Cu2+, was further elucidated through experimental and theoretical methods. Furthermore, the adsorption capacity of TAP-COF toward Cu2+ was investigated, confirming the excellence of TAP-COF as a fluorescent probe and adsorbent for the specific detection and removal of Cu2+. This work holds significant implications for improving environmental and human health concerns associated with Cu2+ contamination.

Synthesis and evaluation of mesoporous silica/mesoporous molecularly imprinted nanoparticles as adsorbents for detection and selective removal of imidacloprid in food samples

The double-mesoporous-layer imprinted polymer of mesoporous silica/mesoporous molecularly imprinted nanoparticles (MIP), with high specific surface area, rich porosity, excellent mass transfer rate and selectivity, were synthesized using imidacloprid (IDP) as a template. Under the optimal conditions of pH, contact time, concentration and temperature, MIP showed high adsorption capacity of 13.86 μg·mg−1 toward IDP and the imprinting factor reached 3.5. The adsorption process model including binding isotherm and kinetics was investigated. MIP exhibited excellent regeneration and its adsorption and selectivity were outstanding among its structurally pesticide analogues. The recovery of spiked IDP for MIP in fortified real samples can reach 96.0 ± 8.5% for cabbage and 105.0 ± 9.9% for apple. The limit of detection of the enrichment method can be as low as 0.037 μg·mL-1 with a good linear relationship (R2 = 0.996) from 0.30 to 10.0 μg·mL−1. The results indicated that the proposed method allowed class-specific detection of IDP in food samples.

Preparation of a Novel Selective Adsorbent for Detection and Measurement of Mercury (II) Ions

In this work, a polymeric adsorbent was synthesized by the imprinting technique for the measurement of Hg (II) ion from aqueous environmental samples. For this purpose, a novel aminothiol monomer has been initially synthesized then it has been used for complexing the mercury. The synthesized complex monomer copolymerized with methacrylic acid and ethylene glycol dimethacrylate and AIBN as the functional monomer, cross-linker and initiator respectively in the presence of a binary porogen of DMSO and toluene. The imprinted polymer was made after removing the mercury (II) ion by an acidic solution of thiourea. The results of batch procedures showed that the Hg (II)-imprinted polymer has adsorption capacity of 28 mg g-1and is high selective for adsorption of Hg (II) ion in competing with the other ions such as CH3Hg (I), Zn (II) and Cd (II) and also in comparing with non-imprinted polymers.

Adsorbents for detection, isolation and evaluation of ethynyl steroids

Adsorbents for detection, isolation and evaluation of ethynyl steroids