Microwave-assisted synthesis of Limonia acidissima Groff gum stabilized palladium nanoparticles for colorimetric glucose sensing

Herein, we present a novel microwave-assisted method for the synthesis of palladium nanoparticles (PdNPs) supported by Limonia acidissima Groff tree extract gum. The synthesized PdNPs were characterized using various analytical techniques, including FTIR, SEM, TEM, UV-visible, and powder XRD analyses. TEM and XRD analysis confirmed that the synthesized LAG-PdNPs are highly crystalline nature spherical shapes with an average size diameter of 7-9 nm. We employed these gum-capped PdNPs to investigate their peroxidase-like activity for colorimetric detection of hydrogen peroxide (H2O2) and glucose. The oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) by H2O2, catalyzed by PdNPs, produces oxidation products quantified at 652 nm using spectrophotometry. The catalytic activity of PdNPs was optimized with respect to temperature and pH. The developed method exhibited a linear range of detection from 1 to 50 µm, with detection limits of 0.35 µm for H2O2 and 0.60 µm for glucose.

Frankincense-Based Functionalized Multiwalled Carbon Nanotubes with Iron Oxide Composites for Efficient Removal of Crystal Violet: Kinetic and Equilibrium Analysis

In this study, novel adsorbents were developed by functionalizing multiwalled carbon nanotubes with frankincense (Fr-fMWCNT) and adding iron oxide (Fe3O4) to the adsorbent (Fr-fMWCNT-Fe3O4). The morphology, surface characteristics, and chemical nature of the synthesized samples were analyzed by using various characterization techniques. The prepared adsorbents were then applied for the elimination of the toxic dye, crystal violet (CV), from water-based solutions by employing a batch adsorption method. The effectiveness of materials for the adsorption of CV was investigated by tuning various effective experimental parameters (adsorbent dosage, dye quantity, pH, and contact time). In order to derive adsorption isotherms, the Langmuir and Freundlich adsorption models were investigated and compared. The Fr-fMWCNT and Fr-fMWCNT-Fe3O4 were found to remove 85 and 95% of the CV dye within 30 min of the adsorption experiment at pH 6, respectively. It was found that a pseudo-second-order reaction rate was consistent with the experimental adsorption kinetics. The equilibrium data demonstrated that the Langmuir model adequately explained the adsorption behavior of the CV dye on the Fr-fMWCNT and Fr-fMWCNT-Fe3O4 surfaces, respectively. According to the Langmuir study, the highest adsorption capacities of the dye are 434 mg/g for Fr-fMWCNT and 500 mg/g for Fr-fMWCNT-Fe3O4. Remediation of the CV dye using our novel composite materials has not been reported previously in the literature. The synthesized Fr-fMWCNT and Fr-fMWCNT-Fe3O4 adsorbents can be economical and green materials for the adsorptive elimination of CV dye from wastewater.

Enhancing Cu2+ Ion Removal: An Innovative Approach Utilizing Modified Frankincense Gum Combined with Multiwalled Carbon Tubes and Iron Oxide Nanoparticles as Adsorbent

Aquatic pollution, which includes organic debris and heavy metals, is a severe issue for living things. Copper pollution is hazardous to people, and there is a need to develop effective methods for eliminating it from the environment. To address this issue, a novel adsorbent composed of frankincense-modified multi-walled carbon nanotubes (Fr-MMWCNTs) and Fe₃O₄ [Fr-MWCNT-Fe₃O₄] was created and subjected to characterization. Batch adsorption tests showed that Fr-MWCNT-Fe₃O₄ had a maximum adsorption capacity of 250 mg/g at 308 K and could efficiently remove Cu²⁺ ions over a pH range of 6 to 8. The adsorption process followed the pseudo-second-order and Langmuir models, and its thermodynamics were identified as endothermic. Functional groups on the surface of modified MWCNTs improved their adsorption capacity, and a rise in temperature increased the adsorption efficiency. These results highlight the Fr-MWCNT-Fe₃O₄ composites' potential as an efficient adsorbent for removing Cu²⁺ ions from untreated natural water sources.

An efficient biosynthesis of palladium nanoparticles using Bael gum and evaluation of their catalytic and antibacterial activity

We report a facile microwave-assisted synthesis of palladium nanoparticles (PdNPs) using Bael gum (BG) and it's carboxymethylated (CMBG) derivative. The prepared nanoparticles (BG@PdNPs and CMBG@PdNPs) were evaluated for antibacterial and catalytic activity in the reduction of organic dye pollutants. The developed synthetic method is simple, low cost and eco-friendly, wherein the process requires no additional reducing or capping agents. The CMBG was prepared via etherification reaction between BG and monochloroacetic acid using Williamson synthesis method. The PdNPs were synthesized using BG and CMBG as stabilizers and reducing agents. The PdNPs were found to be well dispersed spherical, with the crystalline size of the order of 7-21 nm. The results showed that the CMBG@PdNPs were smaller in size (7 ± 2 nm) than those capped with BG@PdNPs (10 ± 2 nm). The catalytic ability of CMBG@PdNPs was examined for the reduction of Methyl Orange (MO), Methyl Red(MR), and Rhodamine-B (RhB) in the presence of NaBH₄. The results showed that CMBG@PdNPs exhibited a higher catalytic ability than BG@PdNPs. Moreover, it was found that CMBG@PdNPs served several times as a retrievable and reusable catalyst which is stable even after six cycles of reaction. The CMBG@PdNPs and BG@PdNPs showed excellent antibacterial activity. The results indicate that CMBG@PdNPs have greater potential application as a catalyst in the reduction of organic pollutants and antibacterial activity.

Microwave-assisted preparation of a silver nanoparticles/N-doped carbon dots nanocomposite and its application for catalytic reduction of rhodamine B, methyl red and 4-nitrophenol dyes

In the current work, a silver nanoparticles/nitrogen-doped carbon dots (AgNPs/NCDs) nanocomposite was prepared by a microwave-assisted method that does not require additional reducing or stabilizing agents. Multiple analytical techniques were used to characterize the prepared nanocomposite. The nanocomposite exhibited a surface plasmon resonance (SPR) absorption peak at 420 nm, indicating the development of AgNPs with NCDs. Further, HRTEM results confirmed the formation of the nanocomposite with the appearance of lattice fringes of both materials. Additionally, the nanocomposite did not show any precipitation even after two months of storage. The nanocomposite exhibited high catalytic activity towards the reduction of rhodamine B (RhB, 98.83%), methyl red (MR, 97.14%) and 4-nitrophenol (4-NP, 99.95%) at ambient temperature. Besides, the kinetic analysis revealed that the reduction reaction followed pseudo-first-order kinetics and the calculated rate constants (k) for rhodamine B (RhB), methyl red (MR) and 4-nitrophenol (4-NP) were found to be 0.0296 s-1, 0.0233 s-1 and 0.029 s-1, respectively. Moreover, it is a reusable and stable catalyst for reduction reactions up to five cycles without significant loss in catalytic activity. Finally, a plausible mechanism for the reduction of pollutants is also discussed in detail. As a whole, the prepared nanocomposite might display stunning behaviour for wastewater treatment applications.

Eco-friendly synthesis of SnSe nanoparticles: effect of reducing agents on the reactivity of a Se-precursor and phase formation of SnSe NPs

Tin monoselenide (SnSe) nanoparticles (NPs) have great potential to replace the conventional absorbers used in the fabrication of thin film solar cells.