Palladium Ions Research Articles

Evaluation of a triethylenetetramine-chitosan derivative for the removal of palladium ion from an intricate adsorbate system

Evaluation of a triethylenetetramine-chitosan derivative for the removal of palladium ion from an intricate adsorbate system

Styrene divinyl benzene beads (SM-2) functionalized with triisobutylphosphine sulfide for selective uptake of palladium(II) from nitric acid medium

Resins impregnated with organic extractants regarded as effective adsorbent materials due to their ability for selective sorption. These resins consist of a polymeric material that is infused with accessible organic extractants. Furthermore, these resins merge the unique properties and the distinctive characteristics of both liquid-liquid extraction and solid-liquid sorption processes. In this work, the impregnation of Styrene divinyl benzene beads (SM-2 beads) with triisobutylphosphine sulfide (TIBPS = CYANEX 471X) was prepared. A SM-2 bead functionalized with CYANEX 471X (SM-2-TIBPS beads) was characterized using scanning electron microscope (SEM) and Fourier-transform infrared spectroscopy (FT-IR) techniques and investigated for recovery and separation of palladium ions from a 3 M nitric acid solution. Various parameters were studied, as shaking time effect, nitric acid concentration, SM-2-TIBPS beads weight, Pd(II) concentration and temperature. The Pd(II)/SM-2-TIBPS sorption system has an endothermic nature and was fitted with a Langmuir isotherm model with a 0.9860 regression factor. The kinetics modeling was fitted with PSO and IPD models with regression factors of 0.9889 and 0.9959, respectively. The maximum monolayer sorption capacity of SM-2-TIBPS was found to be 17.47 ± 0.9 mg/g. The sorption of Pd(II) from different media at 3 M takes the following sequence: HNO3 > HCl > H2SO4. Desorption of about 76.38 ± 2.4% was achieved with (1 M + 1 M) of thiourea + HCl after one desorption stage. Effect of other interfering ions, as Pt(II), Pb(II), Eu(III), Cu(II), Mo(VI), Co(III), Zr(IV), Fe(III), Cd(II), and Ce(III), indicates high separation factors between Pd(II) and other investigated metal ions, which ranged from 9.4 to 35.

Recyclable polyethylenimine based polymer for selective Pd(II) recovery and Suzuki reaction: Waste to treasure tactics

Developing efficient materials for the selective capture of Pd(II) from secondary sources, along with the reutilization of spent Pd(II)-loaded adsorbents, is of great significance, but remains great challenging. Herein, a highly efficient adsorbent (TP@PEI) was fabricated through polycondensation of polyethyleneimine (PEI) with 1,3,5-triformylphoroglucinol (TP), which selectively extracts palladium ions from simulated industrial wastewater, with preferential uptake of Pd(II) over 9 competing cations. The TP@PEI achieves ultrafast capture of Pd(II) in just 20 min, with an impressive adsorption capacity of 620 mg g−1. Of greater significance, the removal efficiency for Pd(II) reaches 99.9 % at a concentration of 100 mg L-1, which still remains at a remarkable 99 % after 11 adsorption–desorption cycles. Exceptional 99.9 % Pd(II) recovery is achieved through the adsorption of a depleted Pd-digested solution, while the breakthrough test validates its practicality and impressive bed breakthrough time (1070 min). Mechanism study reveals that the exceptional adsorption performance of TP@PEI for palladium is driven by synergistic interactions, including coordination and electrostatic interactions. Furthermore, the waste Pd(II) loaded TP@PEI efficiently catalyzes the Suzuki reaction in water, achieving a remarkable 99 % yield of the targeted compound. This research showcases a strategy for converting industrial waste into a valuable resource by meticulously engineering materials to extract precious metals from wastewater, subsequently repurposing them as high-performing catalysts.

Porous chitosan quaternary ammonium salt hydrogel embedded with Cu, Ni and Pd nanoparticles for efficient coupled adsorption-catalytic reduction of methylene blue and 4-nitrophenol

Anthropogenic wastewater generation and water pollution can have negative impacts on public health and ecosystems. However, most materials do not have both adsorptive and catalytic properties, so the design and development of sustainable and multifunctional materials is essential for wastewater treatment. Herein, composite hydrogel (PHG) containing [2-(Methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl) ammonium hydroxide (SBMA) and chitosan quaternary ammonium salts (HACC) were prepared for wastewater treatment. The adsorption capacities of the PHG hydrogels for nickel (NiII), copper (CuII), and palladium (PdII) ions were 158.68, 182.99, and 229.78 mg/g, respectively. The adsorption process is consistent with the Langmuir adsorption model and quasi-secondary kinetics. For further application of adsorbed metal ions, NaBH4 was selected for in situ reduction to prepare hydrogel-based catalysts cemented with metal nanoparticles (Ni-, Cu- and Pd-NPs), respectively. The PHG-Pd catalysts demonstrated significant catalytic efficiency in reducing 4-nitrophenol and methylene blue, and Kapp were 0.307 and 0.365 min−1, respectively. Among them, the activation parameters for the reduction of 4-NP over PHG-Pd catalyst were calculated as Ea = 36.27 kJ/mol, ΔH# = 33.72 kJ/mol and ΔS# = −259.68 J/(mol·K). This study is expected to provide insights into the design of multifunctional adsorption catalysts for the removal of dyes and nitro compounds from wastewater.

An acid-resistant covalent organic polymer for detection of palladium ions in high-level liquid waste

An acid-resistant covalent organic polymer for detection of palladium ions in high-level liquid waste

Design, synthesis, and evaluation of some metal ion complexes of mannich base derived from 2-Mercaptobenzimidazole as potential antimicrobial agents

This study aims to prepare new compounds and investigate them spectroscopically and biologically against selected types of positive and negative bacteria and fungi to demonstrate their biological effectiveness. The prepared ligand combining formaldehyde, indole, sulfa benzamide, and 2-mercapto benzimidazole, a Mannich base ligand (L) was synthesized. The six metal ions including Cobalt (II), Nickel (II), Copper (II), Palladium (II), Platinum (IV), and gold (III) have interacted with the ligand and formed new complexes. Different spectroscopic methods, including C.H.N.S., FTIR, UV- Range visible, 1HNMR, 13CNMR, mass spectra, magnetic moment, and molar conductivity were used to suggest the new geometry of the complexes. The result from the infrared spectrum showed that the ligand behaves as tridentate with all prepared complexes. Conductivity analysis revealed the electrolytic nature of palladium, platinum, and gold ions complexes and non-electrolytes. The antibacterial activity of the compounds that were produced was tested using an agar-well diffusion procedure towards two strains of gram-positive as well as two strains of gram-negative bacteria and fungi (Staphylococcus, Streptococcus, Escherichia coli, Pseudomonas aeruginosa, and Candida albicans) respectively at 0.02M. The standard (∆Eo) and (∆Hfo) of ligand and six complexes were calculated using the program Hyper chem 8.0.7. The research established that complexes are more stable than ligands. Calculated HOMO and LUMO and vibration frequencies using (parametric method 3 (PM3)) to find out the active sites in the ligand showed that they can coordinate and note the extent to which the results of theoretical vibrational frequencies are close to the process when calculating the vibrational frequency of the active aggregates.

Efficient palladium ion adsorption and catalyst preparation from pharmaceutical wastewater using amino-functionalized Ti3C2

This paper reports the recovery and reuse of Pd ions from pharmaceutical wastewater using amino-modified Ti3C2. Ti3C2–NH2 was synthesized by modifying (3-aminopropyl)triethoxysilane and the successful substitution of some surface functional groups of Ti3C2; the decrease in material thickness was verified by characterization. This study revealed that the presence of amino groups significantly enhanced the Pd(II) adsorption capacity of Ti3C2. The effects of the adsorbent material, adsorbent dosage, pH, initial concentration of Pd ions, presence of competing cations, and contact time on the adsorption performance were investigated. The maximum adsorption capacity of 20 mg of Ti3C2–NH2 was 986.65 mg/g in 100 ml of a Pd-ion solution with an initial concentration of 200 mg/l at pH 3. A pseudo-second-order kinetic model fitted well with the experimentally obtained rate data, indicating that the main mode of Pd-ion removal by Ti3C2–NH2 was via chemical reduction. Finally, the catalyst exhibited excellent performances during the photocatalytic and Suzuki coupling reactions with yields of 81 % and 95 %, respectively. The results demonstrated that Ti3C2–NH2 is an excellent material for adsorbing Pd ions and can effectively recycle these ions from pharmaceutical wastewater.

Comparison of In Vitro and In Vivo Biological Screening of Nano‐Palladium (II) and Platinum (II)‐Based Compounds With DFT and Molecular Docking Study

ABSTRACTWithin the current challenges in medicinal chemistry, the creation of novel and improved therapeutic agents stands out. 2‐Cyano‐3‐(thiophen‐2‐yl)prop‐2‐enethioamide (CTPTA) ligand was complexed with palladium (II) and platinum (II) ions within the nanoscale with the molecular formula [M (CTPTA)Cl2]. H2O. The CTPTA ligand and its complexes were characterized by elemental analysis, UV–Vis spectra, FTIR, mass spectra, TGA, magnetic measurement, and the molar conductance technique. Analysis with a scanning electron microscope (SEM) revealed that the nanostructure dimension of both complexes is predominantly between 10 and 30 nm. The CTPTA ligand functions as a bidentate ligand, utilizing thione sulfur, and cyanide nitrogen atoms. Density functional theory was employed to analyze the geometric structure properties of the CTPTA ligand and its complexes. Natural population (NPA) and Mulliken population (MPA) methods were used to calculate the charge distribution. The cytotoxic impact results of all compounds on human liver cancer (HepG2) cell line were satisfactory. The ligand and its complexes were also tested against gram‐negative and gram‐positive bacteria in vitro. The findings of the molecular docking study supported the cytotoxicity and antibacterial effects. The antioxidant and anti‐inflammation activities of synthesized palladium (II) and platinum (II) complexes had a great spectrum of activity. The preclinical pharmacokinetic studies on albino rats revealed that the newly studied complexes achieved excellent antitumor results. This was clear in the investigated parameters, especially the amelioration of AFP levels, liver weight, oxidative stress, and lobular hepatic architecture injury.

Selective separation and determination of palladium ions using isatin-3-(4-phenyl-3-thiosemicarbazone) as a chelating agent via flotation methods from different water samples

Selective separation and determination of palladium ions using isatin-3-(4-phenyl-3-thiosemicarbazone) as a chelating agent via flotation methods from different water samples

Pd Catalysts Supported on Mixed Iron and Titanium Oxides in Phenylacetylene Hydrogenation: Effect of TiO2 Content in Magnetic Support Material.

Recently, Pd catalysts supported on magnetic nanoparticles (MNPs) have attracted a great attention due to their ability of easy separation with an external magnet. Modification of MNPs is successfully used to obtain Pd magnetic catalysts with enhanced catalytic activity. In this work, we discussed the effect of titania content in TiO2/MNPs support materials on catalytic properties of Pd@TiO2/MNPs catalysts in phenylacetylene hydrogenation. TiO2/MNPs composites were prepared by simple ultrasound-assisted mixing of TiO2 and MNPs, synthesized by co-precipitation method. This was followed by deposition of palladium ions on the mixed metal oxides using NaOH as precipitant. The supports and catalysts were characterized using XRD, BET, STEM, EDX, XPS, and a SQUID magnetometer. Pd nanoparticles (5-6 nm) formed were found to be homogeneously distributed on support materials representing the well-mixed metal oxides with TiO2 content of 10, 30, 50, or 70%wt. Testing of the catalysts in phenylacetylene hydrogenation showed that their activity increased with increasing TiO2 content, and the process was faster in alkali medium (pH = 10). The hydrogenation rates of triple and double C-C bonds on Pd@70TiO2/MNPs achieved 9.3 × 10-6 mol/s and 23.1 × 10-6 mol/s, respectively, and selectivity to styrene was 96%. The catalyst can be easily recovered with an external magnet and reused for 12 runs without significant degradation in the catalytic activity. The improved catalytic properties of Pd@70TiO2/MNPs can be explained by the fact that the surface of the support is mainly composed of TiO2 particles, affecting the state and size of Pd species.

N, N’-bidentate ligand anchored palladium catalysts on MOFs for efficient Heck reaction

Metal-organic frameworks (MOFs), recognized as advanced catalyst carriers due to their adjustable porous, diverse structure and highly exposed active sites, have earned increasing attention for their potential to address the longevity of catalytic centers. In this manuscript, we have devised and synthesized a multifunctional amino-pyridine benzoic acid (APBA) ligand to replace the modulator ligand of the MOF-808 and disperse the palladium catalytic centers atomically on the MOF-APBA. The resulting single-site catalytic system, Pd@MOF-APBA, demonstrates preeminent efficiency and stability, as evidenced by a high average turnover number (95000) and a low metal residue (4.8 ppm) in the Heck reaction. This catalyst has exhibited recyclability for multiple runs without significant loss of reactivity for gram-scale reactions. The catalyst’s high activity and efficiency can be attributed to the suitable electrical properties and structures of the N, N’-bidentate ligand for the catalytic palladium ions, postponing their deactivations, including leaching and agglomeration.

Preparation of chitosan resin by two-step crosslinking method and its adsorption for palladium in wastewater

To preserve the activity of amine groups on chitosan, chitosan resin (CR) was synthesized using the reversed-phase suspension two-step crosslinking method for the adsorption of palladium from wastewater. The effects of varying the amounts of chitosan, liquid paraffin, ethyl acetate, formaldehyde solution, and epichlorohydrin on the adsorption capacity of CR were investigated using both single-factor experiments and response surface methodology. The preparation conditions for the chitosan resin were optimized, and its adsorption properties were systematically evaluated. The results indicated that CR exhibited a high saturated adsorption capacity for palladium, reaching 195.22 mg·g−1. The adsorption kinetics followed the pseudo-second-order model, while the adsorption isotherms were well described by the Sips model. Thermodynamic analysis demonstrated that the adsorption process was spontaneous and endothermic. Furthermore, CR maintained exceptional stability, with a palladium removal efficiency exceeding 99.8 % even after eight adsorption-desorption cycles. The primary adsorption mechanism is attributed to the interaction between palladium ions and the protonated amino groups of the chitosan resin.

Effect of Ni Addtion on Electroless Cu for High Density Interconnect PCB Substrate

Introduction Nowadays, high-density interconnect (HDI) printed circuit board (PCB) substrates have been widely applied to high-end electronics to meet the increasing input and output (I/O) density and small footprint area. Micro-via, a tiny structure buried among build-up layers that provide electrical interconnection is a key component in the HDI substrate. However, the preparation of micro-via is facing new challenges. It is not only required that the size of the micro-via scales down to meet the increased interconnect density, but also that the micro-via should withstand severe operating conditions in different scenarios. Therefore, it is of great importance to improve the quality of micro-vias during processing and manufacturing. The micro-via structure is a sandwich structure that is processed by electroless Cu plating and Cu electrolyte plating sequentially, and thus the quality of the electroless Cu layer can significantly affect the reliability of micro-via. In this work, we mainly focused on the electroless Cu plating process and investigated the effect of the electroless Cu deposition speed on the quality of the micro-via structure. SIM and HR-TEM characterizations were employed to investigate the micro-structure inside the electroless Cu layer. Materials and Method In this study, we used the common alkaline ion catalyst method to prepare the electroless Cu layer. The electroless Cu plating and electrolyte Cu plating was conducted on a PCB Resin Coated Copper (RCC) substrate that was cleaned by soft etching in an acid condition. The surface is then pre-dipped in an anionic solution, and palladium ions were adsorbed using an alkaline ion catalyst. The electroless Cu processes adopted in a reaction bath that consists of Cu resource (CuSO4·5H2O), complexing agent (KNaC4H4O6·4H2O) and reductant (HCHO). The whole reaction was conducted in the alkaline condition with a PH of 12.5, and the thickness of the electroless Cu deposition was controlled at around 0.20 µm. NiSO4 is selected as the Ni precursor to alter the Ni concentration in the reation bath. The contents of Ni addition were selected as 50 %, 100 %, 200 % and 300% of a conventional process at a bath temperature of 27 ºC. The thickness of the plated Cu layer was measured by a gravimetric method. Results and discussion TEM observation was used to identify the structure at the interface. Fig. 1 shows the TEM observation of the sample with 50 % and 200 % Ni concentrate. There are some nanovoids found at the interface between the Cu substrate and electroless Cu, which is arguably due to hydrogen generated during electroless Cu plating. The sample with a higher reaction speed has more nanovoids. It can be due to that the higher reaction speed can generate more hydrogen bubbles in the bath that can attach to the electroless Cu layer, leading to nanovoids as shown in Fig. 1. The samples prepared at different bath temperatures are under investigation to illustrate that the reaction speed can significantly affect the Cu electroless layer quality. Conclusions In this work, we investigated the Ni effect in electroless Cu on the RCC substrate. It is found that the higher Ni incorporation can lead to massive nanovoids generation and fine Cu grains in the electroless layer, which is a potential risk for the reliability of the HDI substrate. By reducing the Ni incorporation content, the number of nanovoids can be effectively reduced. Figure 1

Correlation between Zeolitic SiO2/Al2O3 Ratio and the Low-Temperature NOx Adsorption Capacity of Pd/SSZ-13 under Realistic Exhaust Conditions

Passive NOx adsorber (PNA) is one of the important means to effectively reduce NOx emission control in the cold start of a diesel engine. A series of Pd/SSZ-13 catalysts with different SiO2/Al2O3 ratios (11, 17, and 25) were prepared using the impregnation method. Furthermore, the effect of the SiO2/Al2O3 ratio on the adsorption performance of Pd/SSZ-13 at low-temperature NOx under realistic exhaust conditions was studied. The results show that the Pd/SSZ-13 catalyst with a low SiO2/Al2O3 ratio after loading Pd has a higher specific surface area and palladium ion content. There is a negative correlation between NOx adsorption performance and the SiO2/Al2O3 ratio. After high-temperature heat treatment, the acid sites closely related to palladium species increase and palladium species will redisperse, producing more palladium ions. The palladium ions coexist in Pd/SSZ-13 in the form of Pd2+ and Pd+, among which Pd2+ is divided into two types: Z−Pd2+Z− and Z−[Pd(II)OH]+. The NOx adsorption performance of the Pd/SSZ-13 catalyst was significantly improved, and the higher the SiO2/Al2O3 ratio, the more obviously the advantage of NOx adsorption performance increased after heat treatment. The NOx adsorption kinetic model of the Pd/SSZ-13 catalyst under realistic exhaust conditions was most suitably described by the pseudo-first-order model.

Magnesium(II) Porphyrazine with Thiophenylmethylene Groups-Synthesis, Electrochemical Characterization, UV-Visible Titration with Palladium Ions, and Density Functional Theory Calculations.

The presented studies aimed to evaluate the peripheral coordinating properties of a novel porphyrinoid family representative preceded by its synthesis for potential sensing purposes. Two synthetic pathways were employed to a obtain maleonitrile derivative, further used as a starting material in the cyclotetramerization reaction. In the first one, DAMN was used in sequential double-reductive alkylation with 2-thiophene-carboxyaldehyde and sodium borohydride. In the second, DAMN was used in a one-pot reaction with 2-thiophene-carboxyaldehyde in the presence of a 5-ethyl-2-methylpyridine borane complex in methanol and acetic acid. Following the Linstead approach, the cyclization reaction led to a novel symmetrical magnesium(II) octaaminoporphyrazine with methyl(2-thiophenylmethylene) substituents. The macrocycle's electrochemical properties were assessed by cyclic and differential pulse voltammetries revealing one reduction and two oxidation peak potentials. The additional spectroelectrochemical measurements showed formation of a cationic form of the macrocycle at an applied potential of 0.6 V. The coordinating properties due to the palladium ion of novel porphyrazines were measured with the use of titration combined with UV-vis spectrometry. The titration of Pd2+ revealed the good sensing activity of porphyrazine in the range of 0.1 to 5 palladium molar equivalents. In addition, Pd2+ ions coordination was also assessed by electrochemical studies, indicating the peak potential shift of 0.1 V in the presence of metal cations. DFT calculations showed the good agreement between theoretical and experimental data in the UV-vis and 1H NMR studies.

Novel Multi‐Function Chromoionophoric Probe‐Based Nano‐Conjugate Material for Highly Efficient Detection, Removal, and Recovery of Pd(II) and Co(II) Ions from Electronic Wastes and Electroplating Wastewater

AbstractThis study describes the development of a multifunction chromoionophoric probe‐based nano‐conjugate material for the colorimetric determination, recovery, and removal of palladium and cobalt ions (Pd(II) and Co(II)) ions from electronic wastes and electroplating wastewater. The chromoionophoric probe‐based nano‐conjugate material was prepared using a building‐block approach by anchoring the 4‐[(E)‐(2‐hydroxyphenyl)diazenyl]‐1‐nitrosonaphthalen‐2‐ol (HDN) organic chromoionophoric probe onto nano‐spherical silica material carrier. The prepared materials were characterized using different techniques, such as TEM, SEM XRD, and BET. The HDN chromoionophoric probe‐based nano‐conjugate material was evaluated for its effectiveness in detecting and removing Pd(II) and Co(II) ions from electronic wastes and electroplating wastewater by testing various parameters such as pH, sensing system temperature, reaction kinetic, nano‐conjugate material amount, stability of the chromoionophoric probe‐based nano‐conjugate material and the existence of other coexisting metal ions. The HDN chromoionophoric probe‐based nano‐conjugate material demonstrated high selectivity and sensitivity for the colorimetric ion‐sensing of Pd(II) and Co(II) ions, with a detection limit of 7.18 and 208 nM, respectively. The method displayed optimal sensing at pH levels of 6.0 and 8.0 for Pd(II) and Co(II) ions, respectively, and the presence of other metal ions did not meaningfully influence the performance of the ion‐detection due to the powerful ability of the chromoionophoric probe‐based nano‐conjugate material. The adsorption capacity of the chromoionophoric probe‐based nano‐conjugate material towards Pd(II) and Co(II) ions was investigated and the outcomes were 163.40 and 128.57 mg/g, respectively. The chromoionophoric probe‐based nano‐conjugate material could be regenerated by eluting the adsorbed Pd(II) and Co(II) ions with 0.15 M HCl solution. In addition, the material could be reused multiple times, with almost no decrease in its initial performance after regeneration. Based on the findings, the chromoionophoric probe‐based nano‐conjugate material shows potential for environmental recovery, removal, and detection of Pd(II) and Co(II) ions from electronic wastes and electroplating wastewater, indicating its potential as a multi‐function solution for environmental concerns and issue and could be even commercialized and used at a larger scale.

Green emissive nitrogen-doped graphene quantum dots for fluorescence off–on probing methimazole via palladium (II) mediated assay

A palladium ion ([Formula: see text])-mediated nitrogen-doped graphene quantum dots (N-GQDs/Pd[Formula: see text]) was developed as a fluorescent “off–on” probe for methimazole (MZ). Fluorescent N-GQDs interact with Pd[Formula: see text] through coordination interactions, leading to weak photoluminescence (PL) owing to the quenching ability of Pd[Formula: see text]. Upon introducing MZ, the stronger binding between N-GQDs and Pd[Formula: see text] destroys the N-GQDs/Pd[Formula: see text] complex and restores the PL of N-GQDs. The probe exhibits a linear PL response to MZ concentrations from 3.0 to 50.0 [Formula: see text]M with a detection limit down to 4.5 nM. In addition, the probe has been used to detect MZ in real samples including natural water sources and human urine.

Stark broadening of Pd II spectral lines

Stark widths for 47 spectral lines of singly charged palladium ion (Pd II) have been calculated with the help of the modified semiempirical method. The calculations have been performed for an electron density of 1017 cm−3 and for a temperature range from 5 000 K up to 80 000 K. Employing the obtained results, we investigated the influence of Stark broadening in Pd II spectra of DB and DO white dwarfs as well as A type stars. Moreover, similarities and regularities of Stark widths of Pd II spectral lines within a multiplet, a supermultiplet and a transition array have been discussed.

Silica@poly(chitosan-N-isopropylacrylamide-methacrylic acid) microgels: Extraction of palladium (II) ions and in situ formation of palladium nanoparticles for pollutant reduction

Most of the transition metal ions and organic dyes are toxic in nature. Therefore, their removal from water is imperative for human health. For this purpose, various types of systems have been developed to tackle either transition metal ions or organic dyes individually. A core-shell microgel system is introduced which is capable of effectively removing both types (toxic organic dyes and transition metal ions) of pollutants. A long-rod-shaped silica@poly(chitosan-N-isopropylacrylamide-methacrylic acid) S@P(CS-NIPAM-MAA) S@P(CNM) core-shell microgel system was developed by free radical precipitation polymerization method (FRPPM). S@P(CNM) was utilized as an adsorbent for extracting palladium (II) (Pd (II)) ions from water under different concentrations of S@P(CNM), several agitation times, palladium (II) ion content, and pH levels. The adsorption data of Pd (II) ions on S@P(CNM) was evaluated by various adsorption isotherms. The kinetic study was investigated by employing pseudo-2nd order (Ps2O), Elovich model (ElM), intra-particle diffusion (IPDM), and pseudo-1st order (Ps1O). Additionally, palladium nanoparticles (Pd NPs) were generated via in-situ reduction of adsorbed Pd (II) ions within the P(CNM) shell region of S@P(CNM). The resulting Pd NPs loaded S@P(CNM) exhibited the capability to reduce organic pollutants like methyl orange (MeO), 4-nitrophenol (4NiP), methylene blue (MeB), and Rhodamine B (RhB) from aqueous medium. 0.766 min−1, 0.433 min−1, 0.682 min−1, and 1.140 min−1 were the values of pseudo 1st order rate constant (kobs) for catalytic reduction of MeB, 4NiP, MeO, and RhB respectively. The S@Pd-P(CNM) system exhibits significant catalytic potential for various organic transformations.

Tailoring the Coordination Micro-Environment in Nanotraps for Efficient Platinum/Palladium Separation.

Recovering platinum group metals from secondary resources is crucial to meet the growing demand for high-tech applications. Various techniques are explored, and adsorption using porous materials has emerged as a promising technology due to its efficient performance and environmental beingness. However, the challenge lies in effectively recovering and separating individual platinum group metals (PGMs) given their similar chemical properties. Herein, a breakthrough approach is presented by sophisticatedly tailoring the coordination micro-environment in a series of aminopyridine-based porous organic polymers, which enables the creation of platinum-specific nanotraps for efficient separation of binary PGMs (platinum/palladium). The newly synthesized POP-o2NH2-Py demonstrates record uptakes and selectivity toward platinum over palladium, with the amino groups adjacent to the pyridine moieties being vital in improving platinum binding performance. Further breakthrough experiments underline its remarkable ability to separate platinum and palladium. Spectroscopic analysis reveals that POP-o2NH2-Py offers a more favorable coordination fashion to platinum ions compared to palladium ions owing to the greater interaction between N and Pt4+ and stronger intramolecular hydrogen bonding between the amino groups and four coordinating chlorines at platinum. These findings underscore the importance of fine-tuning the coordination micro-environment of nanotraps through subtle modifications that can greatly enhance the selectivity toward the desired metal ions.