Palladium Nanoparticles Research Articles

Green Biosynthesis and Catalytic Application in Environmental Pollutants of Functionalized Pd‐Ag Bimetallic Nanoparticle by Deinococcus Radiodurans Extracts

AbstractCatalytic reduction of organic pollutants using metal nanoparticles (MNPs) as nanocatalyst is a promising approach. The widespread application of MNPs have led to an increase demand for their production. The green biosynthesis of MNPs using microbes is becoming increasingly important as they are benign and environmentally friendly. In this work, Deinococcus wulumuqiensis (D. wulumuqiensis) with high resistance to stresses was applied for the green preparation of different MNPs, including palladium nanoparticles (Pd NPs), silver nanoparticles (Ag NPs), and Pd−Ag bimetallic nanoparticles (Pd−Ag BNPs). The resultant MNPs exhibited a face‐centered cubic structure, with average size of 6.70 (Pd NPs), 6.24 (Ag NPs), and 6.13 nm (Pd−Ag BNPs), respectively. FT‐IR spectra indicated that the proteins and polysaccharides expressed by D. wulumuqiensis could potentially contributed to the formation of MNPs. The application of as‐prepared biocatalyst in catalytic degradation of pollutant dyes demonstrated that Pd−Ag BNPs had greater degradation ability of 4‐nitrophenol (95.1 %) and Rhodamine B (85.1 %) than monometallic nanoparticles. The pseudo‐first‐order kinetics results further indicated the superior catalytic ability of Pd−Ag BNPs, with rate constant of 0.450±0.009 (4‐nitrophenol) and 1.54×10−2 min−1 (Rhodamine B), respectively. Thus, the present study confirms that D. wulumuqiensis represents a promising candidate for the biosynthesis of Pd‐based nanoparticles with small size, which exhibited potential applications as bionanocatalyst in the degradation of water pollutants.

Facile Fabrication of LaFeO 3 Supported Pd Nanoparticles as Highly Effective Heterogeneous Catalyst for Suzuki–Miyaura Coupling Reaction

Supported Pd catalysts have been widely studied due to their enormous potential as candidates for heterogeneous Suzuki–Miyaura coupling reactions. However, the sintering and low activity of active sites still remain challenges. A vesicle‐shaped LaFeO3‐supported Pd catalyst (I‐Pd/LaFeO3) was successfully fabricated using the impregnation method and tested for the Suzuki–Miyaura coupling reaction. Compared to P‐Pd/LaFeO3 prepared with photo‐deposition and Pd/Al2O3 prepared with impregnation, the I‐Pd/LaFeO3 catalyst exhibits significantly higher catalytic activity, stability, and reusability. The chemical composition and electron states of different Pd‐based catalysts were well studied based on various characterizations and the results indicated that the excellent performance of I‐Pd/LaFeO3 can be attributed to its unique nanostructure and the strong interactions between LaFeO3 and palladium nanoparticles. The impregnation method and the choice of the LaFeO3 support show a great influence on the electronic properties of Pd species, their reducibility, and, consequently, their reaction behavior. This unique LaFeO3 supported Pd catalyst provided an environmentally friendly heterogeneous method for the Suzuki–Miyaura coupling reaction.

Size and Shape Dependence of Hydrogen-Induced Phase Transformation and Sorption Hysteresis in Palladium Nanoparticles

Abstract Phase transitions of metals in hydrogen environments are critically important for applications in energy storage, catalysis, and sensing. Nanostructured metallic particles can lead to faster charging and discharging kinetics, increased lifespan, and enhanced catalytic activities. However, establishing a direct causal link between nanoparticle structure and function remains challenging. In this work, we establish a computational framework to explore the atomic configuration of a metal-hydrogen (M-H) system when in equilibrium with a H environment. This approach combines Diffusive Molecular Dynamics with an iteration strategy, aiming to minimize the system's free energy and ensure uniform chemical potential across the system that matches that of the H environment. Applying this framework, we investigate H chemical potential-composition isotherms during the hydrogenation and dehydrogenation of palladium nanoparticles, ranging in size from $3.9$ nm to $15.6$ nm and featuring various shapes including cube, rhombic dodecahedron, octahedron, and sphere. Our findings reveal an abrupt phase transformation in all examined particles during both H loading and unloading processes, accompanied by a distinct hysteresis gap between absorption and desorption chemical potentials. Notably, as particle size increases, absorption chemical potential rises while desorption chemical potential declines, consequently widening the hysteresis gap across all shapes. Regarding shape effects, we observe that, at a given size, cubic particles exhibit the lowest absorption chemical potentials during H loading, whereas octahedral particles demonstrate the highest. Moreover, octahedral particles also exhibit the highest desorption chemical potentials during H unloading. These size and shape effects are elucidated by statistics of atomic volumetric strains resulting from specific facet orientations and inhomogeneous H distributions. Prior to phase transformation in absorption, a H-rich surface shell induces lattice expansion in the H-poor core, while before phase transformation in desorption, surface stress promotes lattice compression in the H-rich core. The magnitude of the volumetric strains correlates well with the size and shape dependence, underlining their pivotal role in the observed phenomena.

Self-supported electrochemical sensor based on uniform palladium nanoparticles functionalized porous graphene film for monitoring H2O2 released from living cells.

Graphene film has been considered a promising material for the construction of self-supported electrodes due to its favorable flexibility and high conductivity. However, the film fabricated from pristine graphene or conventional graphene sheet reduced graphene oxide processes limited electrocatalytic performance. Decorating active metal species or incorporating heteroatoms intothegraphene framework have been proved to be effective methods to enhance the electrocatalytic efficiency of graphene film-based self-supported electrodes. Herein, we present a freestanding electrode composed of uniform Pd nanoparticles decorating N,S co-doped porous graphene film (Pd/NSPGF) and explore its practical application in differentiating various human colon cell types by in situ tracking the amount of H2O2 secreted from live cells. Our findings reveal that, on the one hand, the NSPGF has abundant surface and inner pores, which promote active site exposure, and mass diffusion during electrochemical reactions; on the other hand, the substitutional doping ofthe graphene framework with heteroatoms (e.g., N or S) can tailor its electronic and chemical properties, and facilitate the uniform loading of high-density Pd nanoparticles. Moreover, the intrinsic activity of Pd/NSPGF is regulated by the interaction of Pd nanoparticles withtheNSPGF support. Taking the advantages of morphology and composition, the self-supported Pd/NSPGF electrode displays remarkable electrochemical performance with a wide linear range up to 2.0mM, low detection limit of 0.1μM (S/N = 3), high sensitivity of 665 µA cm-2mM-1, and good selectivity. When applied in real-time trackingofthe H2O2 released from normal human colon epithelial cells and human colorectal cancer cells, the Pd/NSPGF-based electrochemical sensing system can distinguish the cell types by testing the number of extracellular H2O2 molecules released per cell, which holds considerable potential for early detection and monitoring of disease-related clinical specimens.

Insights into Electrocatalytic Hydrogenation of Furfural on Nanoparticulate Pd/C Under Acidic Conditions

In this work, we present an insight into the mechanism of electrochemical hydrogenation of furfural on carbon supported palladium nanoparticles. By directly coupling electrochemistry with mass spectrometry, we were able to, for the first time, deconvolute the hydrogen evolution reaction and electrochemical hydrogenation by measuring the mass signal for hydrogen and 2‐methylfuran. This approach also allowed us to extract the Tafel slopes for each reaction and get insights into mechanisms. The results indicate that the hydrogenation occurs by a Langmuir‐Hinshelwood type process rather than by proton‐coupled electron transfer. Further findings recognize the blocking character of furfuryl alcohol where the latter or one of its intermediates blocks the electrochemical hydrogenation. Additionally, furfuryl alcohol is shown to be a precursor for 2‐methylfuran formation. Accordingly, specific guidelines towards improvement of reaction performance are suggested.

Heterogenization of Palladium Trimer and Nanoparticles through Polymerization Boosted Catalytic Efficiencies in Recyclable Coupling and Reduction Reactions.

The development of heterogeneous palladium catalysts has shown continuous vitality in the field of catalysis and materials. In this work, we report one concise free radicalpolymerization approach to accomplish the aromatic palladium trimer functionalized polymers PSSy-[Pd3]+(2) and itsderived palladium nanoparticles (3). Full characterizationscould confirmthe successful combination of cationic [Pd3]+or nanoparticles with poly(p-sulfonated styrene) skeleton. Compared to their monomeric tri-palladium precursor (1) and commonPd(dba)2, Pd(PPh3)4, Pd(OAc)2, heterogeneous PSSy-[Pd3]+(2) showsmuch superior catalytic activities (0.15 mol%, TOF = 1333.3h-1) in the SMCC reaction. The identically ligated PdNPs (3)are formed in-suitin the presence of NaBH4andaccomplish quantitative reduction of4-nitrophenol in just 320s(0.50 mol%, TOF = 2250 h-1).Moreover, these heterogeneous catalysts arereused for 5-6times without significant loss of catalytic activity. Their superior catalytic ability isprobably attributed to the synergistic effect of polymer entanglement and the tri-palladium fragment.This work enlightensthat the immobilization of palladiumclustersor nanoparticles by polymerization could offer multiple advantages in stability, efficiencyand recyclabilityfortheir involvedcatalyses and show far-reaching future implications.

Synthesis of 3‐Acyl‐1‐Indenones by Oxidative Cyclization of Symmetrical and Unsymmetrical Aryldiynes using Palladium Nanoparticles (Pd‐BNP) as Reusable Nano Catalyst

An efficient, stable and reusable binaphthyl stabilized palladium nanoparticles (Pd‐BNP) catalyzed synthesis of 3‐acyl‐1‐indenone derivatives from oxidative cyclization of symmetrical and unsymmetrical aryldiynes using DMSO as a solvent as well as an oxidant has been established. The scope of the reaction has been studied with various aryldiynes having electron‐donating and electron‐withdrawing groups that afforded good yields. Pd‐BNP catalyst can be recovered and reused for up to four cycles without major changes in particle size and reactivity.

Pd nanoparticles on DUT-67-PZDC-derived N-doped carbon for efficient H2 generation from formic acid dehydrogenation

It is important to develop heterogeneous catalysts with high efficiency and stability to catalyze formic acid (FA, HCOOH) dehydrogenation. Herein, through pyrolysis of DUT-67-PZDC and etching in a hydrofluoric acid (HF) solution, the HF-etched N-doped carbon (HNDC) carrier was obtained. Palladium nanoparticles (Pd NPs), with an average particle size of 3.0 nm, were prepared on the HNDC support using a simple chemical co-reduction method. The optimized Pd/HNDC catalyst demonstrates excellent catalytic activity, the initial turnover frequency (TOF) value is 6001 h−1 at 50 °C with the incorporation of sodium formate (SF) as an additive, and the FA conversion and hydrogen (H2) selectivity could be up to 100%, which is comparable to the majority of MOF-derived heterogeneous catalysts published to date. Additionally, the Pd/HNDC can maintain good stability in five consecutive FA dehydrogenation runs with only a slight decrease. Such remarkable catalytic performance of Pd/HNDC is mainly ascribed to the unique structure of HNDC support with high surface area and hierarchical pore characteristic, the strong synergistic interaction between Pd NPs and the N sites on HNDC, as well as the ultrasmall size and high dispersion of Pd NPs as the catalytic active site. This work offers an efficient method for assembling highly active catalysts for FA dehydrogenation.

Synergistic Palladium Single Sites and Nanoparticles Implanted Into a Novel Zr‐Based Metal–Organic Framework via Solvent‐Free Processing for Upgrading Oxidative Desulfurization Performance

AbstractDesulfurization is a significant approach to producing clean fuel. The design of novel host–guest catalysts with multiple active sites at atomic‐ and nano‐scales, opens a new door to gain an ultrahigh synergistic performance for targeted applications. Herein, an in situ solvent‐free approach is conducted for synchronously implanting Pd single sites (PdSS) and nanoparticles (PdNP) into a novel Zr‐based metal–organic framework (Zr‐MOF). The optimal catalyst exhibits ultrahigh oxidative desulfurization (ODS) performance that can oxidize 1 000 ppm sulfur with diluted oxidant at 40 °C within 5 min. The turnover frequency of the catalyst at 40 °C reaches 774.7 h−1 which is 47.4 times higher than host Zr‐MOF and surpasses the most reported ODS catalysts. A substantial synergistic effect between PdSS and PdNP is responsible for the upgradation of ODS performance. Experimental and theoretical results indicate that PdSS in Zr‐MOF can readily absorb H2O2, and synergistically decompose H2O2 with the assistance of PdNP for accelerated generation of •OH radicals that dominates the ODS performance. This work provides a new solvent‐free way for in situ implanting synergistic catalytic sites into MOFs to upgrade their catalytic performance in targeted reactions.

Cell line-based in vitro models of normal and chronic bronchitis-like airway mucosa to study the toxic potential of aerosolized palladium nanoparticles.

Physiologically relevant cell line-based models of human airway mucosa are needed to assess nanoparticle-mediated pulmonary toxicity for any xenbiotics expsoure study. Palladium nanoparticles (Pd-NP) originating from catalytic converters in vehicles pose health risks. We aimed to develop in vitro airway models to assess the toxic potential of Pd-NP in normal (Non-CB) and chronic bronchitis-like (CB-like) mucosa models. Bronchial mucosa models were developed using Epithelial cells (16HBE: apical side) co-cultured with fibroblast (basal side) at an air-liquid interface. Furthermore, both Non-CB and CB-like (IL-13 treatment) models with increased numbers of goblet cells were used. The models were exposed to 3 different doses of aerosolized Pd-NP (0.2, 0.3, and 6 μg/cm2) using XposeALI® and clean air as a control. After 24 h of incubation, the expression of inflammatory (IL6, CXCL8, TNFα, and NFKB), oxidative stress (HMOX1, SOD3, GPx, and GSTA1), and tissue injury/repair (MMP9/TIMP1) markers was assessed using qRT-PCR. The secretion of CXCL-8 and the expression of a tissue injury/repair marker (MMP-9) were measured via ELISA. Significantly (p < 0.05) increased expressions of CXCL8, IL6, and NFKB were observed at the highest dose of Pd-NP in CB-like models. However, in Non-CB mucosa models, a maximum effect on TNFα and NFKB expression was observed at a medium Pd-NP dose. In Non-CB mucosa models, SOD3 showed a clear dose-dependent response to Pd-NP exposure, while GSTA1 expression was significantly increased (p < 0.05) only at the lowest dose of Pd-NP. The secretion of CXCL-8 increased in a dose-dependent manner in the Non-CB mucosa models following exposure to Pd-NP. In CB-like models, exposure to high concentrations of Pd-NP significantly increased the release of MMP-9 compared to that in other exposure groups. The combination of our Non-CB and CB-like mucosa models with the XposeALI® system for aerosolized nanoparticle exposure closely mimics in vivo lung environments and cell-particle interactions. Results from these models, utilizing accessible cell lines, will maximize the reliability of in vitro findings in human health risk assessment.

Nanoscale Imaging of Palladium-Enhanced Photocatalytic Reduction of 4-Nitrothiophenol on Tungsten Disulfide Nanoplates.

Two-dimensional (2D) dichalcogenides are modern nanomaterials with unique physical and chemical properties. These materials possess band gaps in the infrared and visible regions of the electromagnetic spectrum that can be tuned by their molecular composition. Excitons generated as a result of such light-matter interactions are capable of catalyzing chemical reactions in molecular analytes present on the dichalcogenide surfaces. However, the photocatalytic properties of such nanomaterials remain poorly understood. In the current study, we utilize tip-enhanced Raman spectroscopy (TERS) to examine photocatalytic reduction of 4-nitrothiophenol (4-NTP) to p,p'-dimercaptoazobisbenzene (DMAB) on tungsten disulfide (WS2) nanoplates and WS2 coupled with palladium nanoparticles (WS2@PdNPs). Our results indicate that although both WS2 and WS2@Pd were capable of reducing 4-NTP into DMAB, the metallic hybrid demonstrated much greater yield and rates of DMAB formation compared to WS2 nanoplate. These results indicate that coupling of catalytic metals to dichalcogenides could be used to enhance their catalytic properties.

Ultrafine Pd nanoparticles confined in naphthalene-based covalent triazine frameworks for efficient and stable hydrogen production from formic acid

Formic acid (FA) is considered as a kind of promising hydrogen storage materials due to its economic feasibility, safety, stability and high hydrogen density. Nevertheless, it is a challenge to design a high-performance catalyst with high activity, selectivity and stability for the dehydrogenation of FA to generate hydrogen (H2). Herein, a range of covalent triazine frameworks (CTFs including 1,8-CTF, 1,5-CTF and 2,3-CTF) with abundant nitrogen atoms are developed to support palladium nanoparticles for efficiently catalyzing FA dehydrogenation. Ultrasmall palladium nanoparticles with a size of 1.2 ± 0.3 nm showed near 100 % H2 selectivity and high catalytic activity in FA dehydrogenation supported by 1,8-CTF. The activation energy of FA dehydrogenation catalyzed by Pd/1,8-CTF reaches 26.17 kJ·mol−1. In addition, Pd/1,8-CTF exhibits high stability and easy recyclability, and the catalytic activity is maintained even after 6 cycles. This work gives a feasible strategy to develop high-efficiency and selective nanocatalysts for H2 production from FA dehydrogenation.

Bio-based fabrication of palladium nanoparticles by using Aegle marmelos leaf extract for biomedical applications: Cytotoxicity, cell imaging studies in HeLa cells and antioxidant activity

This paper presents the outcome of medicinal plant-derived synthesis of nanomaterial. The results in the present study provide a simple, novel, sustainable, and economically noble process for the synthesis of palladium nanoparticles using leaf extract Aegle marmelos (A. marmelos). Fourier transformed infrared spectroscopy (FTIR) was used to verify the surface layer of synthesized palladium (ALE@Pd) nanoparticles (NPs) enriched with several kinds of phytochemicals. Transmission electron microscopy (TEM) revealed that the synthesized NPs possess a ball shape and the average diameter was 4.31 ± 1.89 nm. The synthesized NPs possess stability confirmed by UV–visible (UV–Vis) spectrophotometry. The face-centered cubic (FCC) crystal structure of the fabricated nanoparticles was confirmed by powder X-ray diffraction (PXRD). Fabricated ALE@Pd NPs are subjected to further testing for their cytotoxicity in HeLa cell lines, as well as for a comparative study of antioxidant activity between the A. marmelos leaves and prepared ALE@Pd NPs. The anti-carcinogenic activity and cell imaging in HeLa cells were tested, and the minimal inhibition concentration (MIC or IC50) has been determined and found to be around 46 µg/mL for HeLa cell lines. Fabricated palladium nanoparticles derived from A. marmelos have the potential to be employed as an environmentally friendly and cost-effective anticancer agent. Furthermore, synthesized ALE@Pd NPs possess higher antioxidant activity than A. marmelos leaves extract (ALE) due to the increased phenolic content connected to the surface of produced palladium NPs as a capping agent. The minimal inhibition concentration of synthesized ALE@Pd NPs was found to be ∼5 µg/mL.

Boosting catalytic activity of π-π interactions-stabilized PdNPs for water-mediated Suzuki couplings of aryl chlorides

Utilizing unique interactions to enhance the catalytic performance of supported metal catalysts is a crucial strategy in catalyst design, albeit one that presents a significant challenge. This study introduces an original approach involving the use of π-π interactions to stabilize palladium nanoparticles (PdNPs) with a 2Br-substituted imidazolium-based covalent organic framework (COF, IHP-Br-PdNPs) for efficient water-mediated Suzuki reactions involving deactivated aryl chlorides and arylboronic acids at ambient conditions. Through extensive structural characterization employing techniques including Fourier transform infrared spectroscopy (FT-IR), cross-polarization magic angle spinning carbon-13 nuclear magnetic resonance (CP/MAS 13C NMR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-angle annular dark field scanning transmission electron microscopy (HAADF-STEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA), N2 adsorption, and X-ray photoelectron spectroscopy (XPS), we demonstrate the immobilization of highly stable and well-dispersed PdNPs was obtained. The designed IHP-Br-PdNPs demonstrate stability for up to 36 months in ambient air and can be efficiently recycled. After 9 catalytic cycles, there was no significant decline in catalytic performance, and the particle size of PdNPs remained constant at approximately 4-8 nm throughout the reactions. The coordination mode between the stabilizer and metal, specifically the π-π interaction between the 2Br-substituted imidazolium moiety and the Pd metal surface, plays a key role in stabilizing various active species and facilitating distinct catalytic pathways. This study provides valuable insights into the development of π-π interactions supported metal catalysts, which enhance stability and catalytic activity in advanced water-mediated synthesis applications.

In situ synthesis and deposition of palladium nanoparticles on gas diffusion layers via gamma radiolysis for cathode electrodes in proton exchange membrane fuel cells

This study investigates gamma radiolysis technique for synthesising and depositing palladium (Pd) nanoparticles on gas diffusion layers (GDLs). The Pd-coated GDLs were then used to fabricate MEAs, which were evaluated for their single-cell performance. The fabricated PEMFCs with Pd-loaded GDLs successfully generated potential and produced electricity, with the PEMFC with a Pd-loaded GDL prepared using a 0.05 M Pd precursor solution and 50 KGy dose achieved performances comparable to the PEMFC with commercial gas diffusion electrodes (GDEs). This study represents the first demonstration of a functional PEMFC using a novel gamma radiolysis-synthesised Pd catalyst GDL as the cathode electrode.

Biochar: Preserving the Long-Term Catalytic Activity of Biosynthesized PdNPs/AuNPs in Cr(VI) Reduction

Palladium nanoparticles (PdNPs) and gold nanoparticles (AuNPs) synthesized within yeast biomass can be effectively preserved in yeast biochar while maintaining their catalytic activity. Herein, we observe well-preserved PdNPs/AuNPs within yeast biochars, alongside the retention of cell morphology. Notably, the crystal structures of AuNPs within biochars exhibit similarity to that of uncarbonized samples, suggesting minimal influence of carbonization on nanoparticle structure. XPS analysis reveals the transformation of organic bacterial cells into heterocyclic aromatic-carbon material during pyrolytic carbonization. Chemical states analysis indicates the prevalence of metallic Pd(0)/Au(0) with limited PdOx/AuOx content in yeast biochars. FTIR analysis highlights increased aromaticity of biochars with typical bands for aromatic ring, and new bands appeared in Pd/Au-loaded biochars possibly attribute to PdOx/AuOx. Moreover, yeast biochars exhibit significantly improved Cr(VI) removal capacities compared to yeast biomass. Specifically, we detect complete removal within 18h for CYPd and CYPdG biochars, contrasting with less than 65% removal efficiency in yeast biomass. These findings underscore the potential of carbonization in enhancing the long-term catalytic activity of biosynthesized PdNPs/AuNPs for efficient Cr(VI) reduction, offering promising avenues for environmental remediation strategies.

Integrating recognition peptide into a nanozyme to mimic uricase binding pocket as a multifunctional nanoplatform for highly selective uric acid recognition, sensing and degrading

Nanozyme based colorimetric sensor for physiological biomarkers detection is becoming an increasingly influential technology in diagnosis, but the selective discrimination of biomarkers using single nanozyme without natural enzyme is greatly challenging. Here, a colorimetric detection platform for biomarker is successfully constructed by integrating recognition peptide (RGPT) into a nanozyme to mimic the binding pocket in natural enzyme. Firstly, RGPT-ultrafine palladium nanoparticles (PdNPs)@reduced graphene oxide (rGO) composite was facilely prepared using an arginine-rich RGPT. RGPT-PdNP@rGO composite displays outstanding laccase-like activity with Km being 0.075 mM at significantly low dosage used, which is one magnitude lower than that of natural enzyme. RGPT-PdNP@rGO nanozyme based one-step sensor can selectively detect uric acid (UA) with a comprehensive linear range from 0.2 to 110 μM and a limit of detection of 120 nM. Moreover, RGPT-PdNP@rGO composite displays an outstanding activity for UA oxidation with Km being 0.024 mM, revealing the nanozyme exhibits a similar affinity towards UA as natural uricase due to the cooperation of the three components. Compared with our previous work, these extremely improved UA recognition, sensing and degrading performances not only support the role of RGPT in enhancing with the recognition ability of the composite nanozyme for targeted UA, but also reveal the recognition role of RGPT is associated closely with inorganic components in the composite. This work provides more definitive and comprehensive information about multifunctional nanozymes for precise biomarker recognition by introducing recognition peptide, which is highly significant for applications beyond mimic-enzyme catalyst, including theranostic, sensing, and energy fields.

Enhanced performance of novel green synthesized CuS nanostructures decorated with Rh and Pd nanoparticles for energy generation and gas sensing applications

This article investigates the utilization of copper sulfide (CuS) based nanomaterials functionalized with rhodium (Rh) and palladium (Pd) nanoparticles for gas sensing and energy generation applications. CuS nanoparticles, known for their unique properties, were combined with Rh and Pd nanoparticles to enhance hydrogen (H2) gas sensing capabilities. Gas sensing experiments revealed that CuS/Rh/Pd nanocomposites exhibited the highest sensing response of 58.33% to H2, indicating the significant improvement in gas sensing properties due to the combined presence of Rh and Pd nanoparticles in CuS matrices. Moreover, temperature-dependent responses provided insights into optimal operating conditions for effective gas sensing with CuS-based nanocomposites. Comprehensive characterization studies including XPS, Raman, and morphology analysis confirmed the successful synthesis of CuS/Rh/Pd nanomaterials with high purity and desirable structural properties. Dye-sensitized solar cell (DSSC) performance studies demonstrated that CuS/Rh/Pd nanocomposites enhanced the efficiency by minimizing light over-absorption and improving photoanode stability. Overall, this study highlighted the potential of metal nanoparticle-decorated CuS nanocomposites for advanced gas sensing and energy generation applications, paving the way for the development of highly sensitive and efficient gas sensors and solar energy conversion technologies.

A new Schiff-base complex of palladium nanoparticles on modified Fe3O4 with 3,5-diaminobenzoic acid (DAA) as a robust, reusable, and selective catalyst in the C[sbnd]N and C[sbnd]C coupling reactions

A Pd Schiff base complex was immobilized onto the surface of magnetic Fe3O4 as a novel, green, and recyclable heterogeneous nanocatalyst and fully characterized by TEM, XRD, FT-IR, BET, SEM, ICP-OES, EDS, TGA, and VSM techniques. The Fe3O4@SiO2@DAA@Schiff base-Pd(0) catalyst exhibits outstanding performance in catalyzing Buchwald-Hartwig and Stille coupling reactions, resulting in high yields of the corresponding products. This catalyst offers numerous benefits, such as a straightforward testing procedure, environmentally friendly reaction conditions, absence of hazardous solvents, quick reaction time, low catalyst usage, and the ability to be reused. Furthermore, the nanocatalyst could be effortlessly separated from the reaction mixture using a bar magnet, enabling its repeated recovery and reuse without compromising its stability or activity.

Apple polysaccharide stabilized palladium nanoparticles for sensitive detection of organophosphorus pesticide.

The widespread application of organophosphorus pesticides (OPs) has inflicted significant damage on human well-being and food security. Hence, it is imperative to develop a friendly and accessible biosensor for the detection of OPs. Herein, apple polysaccharide (AP) stabilized palladium nanoparticles (AP-PdnNPs) with a particle size of 2.75-5.95nm were prepared using AP as a stabilizer and reducing agent. AP-Pd30NPs exhibited good peroxidase-like activity and effectively decomposed H2O2 to ·OH, which catalyzed the 3,3',5,5'-tetramethylbenzidine system to become blue. The catalytic kinetics of AP-Pd30NPs conformed to the typical Michelis-Menten equation. Furthermore, OPs directly inhibited the peroxidase-like activity of AP-Pd30NPs. Thus, a highly effective colorimetric biosensor was developed for the detection of OPs. The detection range of the biosensor was 0.050μg/L - 200mg/L, and the limit of detection was extremely low to 0.010μg/L. Compared with other nanomaterials, the detection platform based on AP-Pd30NPs can effectively detect organophosphorus pesticides without coupling natural enzymes；this method is more economical and practical. Therefore, this established method explores good perspective for the detection of OPs.