Pd Nanorods Research Articles

Palladium Nanoparticles and Lung Health: Assessing Morphology-Dependent Subacute Toxicity in Rats and Toxicity Modulation by Naringin - Paving the Way for Cleaner Vehicular Emissions.

The release of palladium nanoparticles (PdNPs) from autocatalytic converters has raised concerns regarding public health and the environment due to their emergence as anthropogenic contaminants. With growing vehicular population, there is an urgent need for comprehensive toxicological studies of PdNPs to mitigate their risk. The present study aims to investigate the effects of spherical PdNPs with average sizes of 20 and 80 nm, as well as Pd nanorods, on the lung function of female Wistar rats following oral exposure to environmentally relevant doses (1 and 10 μg/kg) over a period of 28 days. Various biological parameters were evaluated, including liver and kidney biochemical changes, lung oxidative stress markers (SOD, CAT, GSH, LPO), lung inflammatory markers (IL-1β, IL-8, IL-6, and TNF-α), and histopathological alterations in the lungs. Additionally, the potential mitigating effects of naringin on PdNPs-induced toxicity were examined. The results demonstrate a significant increase in oxidative stress, the onset of inflammation, and histological changes in lung alveolar sacs upon exposure to all tested particles. Specifically, 20@PdNPs and PdNRs exhibited higher cytotoxicity and pro-inflammatory properties compared to 80@PdNPs. Naringin effectively attenuated the pulmonary toxicity induced by PdNPs by modulating oxidative and inflammatory pathways. These findings contribute to the sustainable development of PdNPs for their future applications in the biomedical and environmental sectors, ensuring the advancement of safe and sustainable nanotechnology.

Bio-reticulation of Pd nanorods enables catalytic treatment of various cloth dyes

Bio-reticulation of Pd nanorods enables catalytic treatment of various cloth dyes

Binder-free Cu/Cu2O/CuO/Pd nanorods photoelectrode for regulating the faradaic efficiency for acetaldehyde and acetate production during photoelectrochemical CO2RR by stabilizing the Cu2O phase

The development of efficient photoelectrodes to accelerate photoelectrochemical carbon dioxide reduction reaction (PEC-CO2RR) to obtain value-added chemicals or fuels is remarkably significant. Although Cu2O-based three-dimensional (3D) heterojunctions have emerged as promising materials for the selective generation of C2 products, they are still plagued by the stability of Cu+ in the Cu2O phase. In this work, we developed a binder-free Cu/Cu2O/CuO/Pd nanorods heterojunction via simple oxidation/reduction procedures to stabilize Cu+ in the Cu2O phase by incorporating high-work function Pd nanoparticles as a co-catalyst. The incorporated Pd not only stabilizes Cu+ through charge transfer from Cu2O to Pd but also enhances the stability of the *CO intermediate to improve C–C coupling for the formation of the C2 products, primarily acetate, and acetaldehyde. The Cu/Cu2O/CuO/Pd photoelectrode exhibits a superior Faradaic efficiency (FE) to produce acetate (21.4%) acetate and acetaldehyde (20.8%) at a negative potential of − 1.4 V (vs RHE), which are 3.5 and 19 times higher than that of Cu/Cu2O/CuO photoelectrode. Moreover, the Cu/Cu2O/CuO photoelectrode produces a maximum hydrogen gas evolution of ∼70% at − 1.2 V (vs RHE). Furthermore, compared to the Cu/Cu2O/CuO photoelectrode, the Cu/Cu2O/CuO/Pd photoelectrodes exhibit remarkable stability for a 5-h operation even at a higher negative applied potential of − 1.2 V vs RHE in CO2-saturated 0.1 M KHCO3. The stabilization of the Cu2O (111) phase is confirmed by the appearance of a characteristic X-ray diffraction and X-ray photoelectron peaks after PEC-CO2RR. These results indicate that the proposed high-stability Cu/Cu2O/CuO/Pd photoelectrode provides a new pathway to produce more C2 products of acetaldehyde and acetate.

Epitaxial growth triggered core-shell Pd@RuP nanorods for high-efficiency electrocatalytic hydrogen evolution

Ru with Pt-like hydrogen bond strength, knockdown cost (∼1/3 of Pt), and eximious stability is a competitive replacement for Pt-based catalysts towards the hydrogen evolution reaction (HER) in water splitting. The design of Ru-based catalysts via interface construction, crystal phase control, and specific light element doping to realize the impressive promotion of limited activity and stability remains challenging. Herein, we report the fabrication of Pd@RuP core-shell nanorods (NRs) via an epitaxial growth method, where ultrathin RuP shells extend the face-centered cubic (fcc) crystal structure and (111) plane of the Pd NRs core. Density functional theory results confirm that the core-shell interface engineering and P doping synergistically accelerate electron transfer and moderate the d-band center to generate a suitable affinity for H*, thus optimizing HER kinetics. Compared with Pd@Ru NRs and Pt/C, the Pd@RuP NRs exhibit preferable electrocatalytic stability and superior activity with a low overpotential of 18 mV at 10 mA cm−2 in the alkaline HER process. Furthermore, the integrated Pd@RuP//RuO2-based electrolyzer also displays a low operation potential of 1.42 V to acquire 10 mA cm−2, demonstrating great potential for practical water electrolysis. Our work presents an efficient avenue to design Ru-based electrocatalysts via epitaxial growth for extraordinary HER performance.

Palladium-Percolated Networks Enabled by Low Loadings of Branched Nanorods for Enhanced H2 Separations.

Nanoparticles (NPs) at high loadings are often used in mixed matrix membranes (MMMs) to improve gas separation properties, but they can lead to defects and poor processability that impede membrane fabrication. Herein, it is demonstrated that branched nanorods (NRs) with controlled aspect ratios can significantly reduce the required loading to achieve superior gas separation properties while maintaining excellent processability, as demonstrated by the dispersion of palladium (Pd) NRs in polybenzimidazole for H2 /CO2 separation. Increasing the aspect ratio from 1 for NPs to 40 for NRs decreases the percolation threshold volume fraction by a factor of 30, from 0.35 to 0.011. An MMM with percolated networks formed by Pd NRs at a volume fraction of 0.039 exhibits H2 permeability of 110Barrer and H2 /CO2 selectivity of 31 when challenged with simulated syngas at 200°C, surpassing Robeson's upper bound. This work highlights the advantage of NRs over NPs and nanowires and shows that right-sizing nanofillers in MMMs is critical to construct highly sieving pathways at minimal loadings. This work paves the way for this general feature to be applied across materials systems for a variety of chemical separations.

Self-Supported Pd Nanorod Arrays for High-Efficient Nitrate Electroreduction to Ammonia.

Electrochemical nitrate (NO3 - ) reduction to ammonia (NH3 ) offers a promising pathway to recover NO3 - pollutants from industrial wastewater that can balance the nitrogen cycle and sustainable green NH3 production. However, the efficiency of electrocatalytic NO3 - reduction to NH3 synthesis remains low for most of electrocatalysts due to complex reaction processes and severe hydrogen precipitation reaction. Herein, high performance of nitrate reduction reaction (NO3 - RR) is demonstrated on self-supported Pd nanorod arrays in porous nickel framework foam (Pd/NF). It provides a lot of active sites for H* adsorption and NO3 - activation leading to a remarkable NH3 yield rate of 1.52mmolcm-2 h-1 and a Faradaic efficiency of 78% at -1.4V versus RHE. Notably, it maintains a high NH3 yield rate over 50 cycles in 25h showing good stability. Remarkably, large-area Pd/NF electrode (25cm2 ) shows a NH3 yield of 174.25mgh-1 , be promising candidate for large-area device for industrial application. In situ FTIR spectroscopy and density functional theory calculations analysis confirm that the enrichment effect of Pd nanorods encourages the adsorption of H species for ammonia synthesis following a hydrogenation mechanism. This work brings a useful strategy for designing NO3 - RR catalysts of nanorod arrays with customizable compositions.

Synthesis and characterization of palladium nanoparticles by varying size, shape and synthetic approach: A comparative risk assessment study in-vitro as a step towards the development of safe and sustainable nanotechnology

The vigorous growth in the equipment of palladium in the autocatalytic converters for mitigating air pollution has led to the release of airborne palladium micro- and nano-particulates in the environment, thus, consequently exposing the occupational workers and urban population to Pd particles, in both fine and ultra-fine fractions. Pd-NPs have been shown to exert cytotoxic and pro-inflammatory effects on the in-vitro and in-vivo models, however, the influence of size, shape and synthetic route on the immunotoxic potential of Pd-NPs is not known yet. Therefore, in this first report, we synthesized Pd microparticles (Pd-MPs), spherical-shaped Pd-NPs via the chemical route (reverse micelle/microemulsion method) and green route using Cannabissativa L. leaf extract (CS–Pd-NPs) and Pd nanorods (Pd-NRs). Characterization techniques such as UV-VIS spectroscopy, TEM, size distribution analysis and FT-IR spectroscopy were used. Further, synthesized particles of environment-relevant concentration were exposed to macrophage cell lines and their cytotoxicity was assessed by MTT assay, Annexin V FITC apoptosis assay and ELISA. Results showed dose-dependent cytotoxicity exerted by all particles when exposed to macrophage cell lines. Among these, Pd-MPs of size ⁓218 nm were found to have the highest cell viability whereas spherical-shaped Pd-NPs of size ⁓4 nm were found to be the least viable as compared to other particles at all concentrations. Apoptosis induced by all the particles was not found to be significant (<3%). ELISA studies showed a minimal rise in TNF-α and IL-6 cytokine levels as compared to control whereas Pd-MPs and CS-Pd-NPs had an insignificant effect on the markers. Through this study, we also gain an insight into the exact size and shape that have the least toxicity for their future applicability in biomedical, industrial and environmental fields to ensure safe and sustainable nanotechnology and environmental safety from their use.

Construction and preparation of coated Z-scheme NaGdF4:Nd3+,Yb3+,Tm3+@CdS-Pd@NiO photocatalyst with core-shell structure for organic pollutant degradation with synchronous hydrogen evolution

A coated Z-scheme NaGdF4:Nd3+,Yb3+,Tm3+@CdS-Pd@NiO photocatalyst with core-shell structure is prepared by hydrothermal and coprecipitation methods. NaGdF4:Nd3+,Yb3+,Tm3+ as excellent up-conversion luminescent material can convert infrared light into visible light, broadening the light response range of CdS. Pd nanorods act as conductive channels and co-catalysts, leading to successful construction of titled photocatalyst, increasing contact area between two monomer photocatalysts, promoting transfer of photo-generated electrons. It also provides a large oxidation surface for organic pollutant degradation. The performance of prepared photocatalyst is assessed by Congo red degradation and hydrogen production. The emission spectrum and energy conversion mechanism of NaGdF4:Nd3+,Yb3+,Tm3+ are investigated. The photocatalyst with 3:1 NaGdF4:Nd3+,Yb3+,Tm3+@CdS-Pd and NiO mass ratio has a preeminent activity. Congo red degradation ratio and hydrogen production amount reach 92.48% and 653.06 µmol/g, respectively, under simulated sunlight irradiation for 180 min. The possible mechanism of organic pollutant degradation with synchronous hydrogen production caused by titled photocatalyst is proposed.

Surface-Functionalized Au-Pd Nanorods with Enhanced Photothermal Conversion and Catalytic Performance.

Bimetallic nanostructures comprising plasmonic and catalytic components have recently emerged as a promising approach to generate a new type of photo-enhanced nanoreactors. Most designs however concentrate on plasmon-induced charge separation, leaving photo-generated heat as a side product. This work presents a photoreactor based on Au-Pd nanorods with an optimized photothermal conversion, which aims to effectively utilize the photo-generated heat to increase the rate of Pd-catalyzed reactions. Dumbbell-shaped Au nanorods were fabricated via a seed-mediated growth method using binary surfactants. Pd clusters were selectively grown at the tips of the Au nanorods, using the zeta potential as a new synthetic parameter to indicate the surfactant remaining on the nanorod surface. The photothermal conversion of the Au-Pd nanorods was improved with a thin layer of polydopamine (PDA) or TiO2. As a result, a 60% higher temperature increment of the dispersion compared to that for bare Au rods at the same light intensity and particle density could be achieved. The catalytic performance of the coated particles was then tested using the reduction of 4-nitrophenol as the model reaction. Under light, the PDA-coated Au-Pd nanorods exhibited an improved catalytic activity, increasing the reaction rate by a factor 3. An analysis of the activation energy confirmed the photoheating effect to be the dominant mechanism accelerating the reaction. Thus, the increased photothermal heating is responsible for the reaction acceleration. Interestingly, the same analysis shows a roughly 10% higher reaction rate for particles under illumination compared to under dark heating, possibly implying a crucial role of localized heat gradients at the particle surface. Finally, the coating thickness was identified as an essential parameter determining the photothermal conversion efficiency and the reaction acceleration.

Sustainable, Green, and Continuous Synthesis of Fivefold Palladium Nanorods Using l-Ascorbic Acid in a Segmented Millifluidic Flow Reactor.

Pd nanorods (PdNRs) have recently come to attention due to their wide array of applications. The green synthesis of PdNR with a relatively high yield and high aspect ratio is challenging. A continuous millifluidic flow reactor (CMFR) has been explored to precisely control mass and heat transfer as well as mixing in the PdNR synthesis processes. CMFRs demonstrate a few drawbacks, such as the presence of parabolic velocity profile in the laminar flow of the reaction solution, causing uneven axial residence time distribution. The CMFRs are likely to show irreversible fouling, which may cause the product quality to deteriorate or result in the channel being clogged. These shortcomings can be avoided or minimized using a segmented millifluidic flow reactor (SMFR) that consists of the solution forming a train of individual segments in another inert medium. This study explores the use of a sustainable reducing agent (l-ascorbic acid) in the presence of potassium bromide (KBr) as the capping agent and poly(vinyl pyrrolidone) (PVP) as the stabilizing agent for PdNR synthesis in an SMFR employing compartmentalized flow of a reaction solution, in which liquid segments consisting of a reaction solution will be immersed in the steam generated by boiling of the solvent water. The effect of reaction parameters such as reagent concentration has been studied on the size and morphology of synthesized Pd nanostructures. A kinetic study has been conducted to calculate the rate of reduction that can be used as a quantitative measure for manipulation of the type and relative concentration of initially formed seeds. It has been shown that the initial reduction rate during the first 45 min of residence time of the millifluidic reactor is about 66% faster compared to the rest of the reaction. A filtration procedure has been utilized to separate Pd nanostructures other than nanorods synthesized in the SMFR.

Synthesis of Pd nanorod arrays on Au nanoframes for excellent ethanol electrooxidation.

Au-Pd hollow nanostructures have attracted a lot of attention because of their excellent ethanol electrooxidation performance. Herein, we report a facile preparation of Au nanoframe@Pd array electrocatalysts in the presence of cetylpyridinium chloride. The reduced Pd atoms were directed to mainly deposit on the surface of the Au nanoframes in the form of rods, leading to the formation of Au nanoframe@Pd arrays with a super-large specific surface area. The red shift and damping of the plasmon peak were ascribed to the deposition of the Pd arrays on the surface of the Au nanoframes and nanobipyramids, which was verified by electrodynamic simulations. Surfactants, temperature and reaction time determine the growth process and thereby the architecture of the obtained Au-Pd hollow nanostructures. Compared with the Au nanoframe@Pd nanostructures and Au nanobipyramid@Pd arrays, the Au nanoframe@Pd arrays exhibit an enhanced electrocatalytic performance towards ethanol electrooxidation due to an abundance of catalytic active sites. The Au NF@Pd arrays display 4.1 times higher specific activity and 13.7 times higher mass activity than the commercial Pd/C electrocatalyst. Moreover, the nanostructure shows improved stability towards the ethanol oxidation reaction. This study enriches the manufacturing technology to increase the active sites of noble metal nanocatalysts and promotes the development of direct ethanol fuel cells.

Advancing Plasmon-Induced Selectivity in Chemical Transformations with Optically Coupled Transmission Electron Microscopy

Nanoparticle photocatalysts are essential to processes ranging from chemical production and water purification to air filtration and surgical instrument sterilization. Photochemical reactions are generally mediated by the illumination of metallic and/or semiconducting nanomaterials, which provide the necessary optical absorption, electronic band structure, and surface faceting to drive molecular reactions. However, with reaction efficiency and selectivity dictated by atomic and molecular interactions, imaging and controlling photochemistry at the atomic scale are necessary to both understand reaction mechanisms and to improve nanomaterials for next-generation catalysts. Here, we describe how advances in plasmonics, combined with advances in electron microscopy, particularly optically coupled transmission electron microscopy (OTEM), can be used to image and control light-induced chemical transformations at the nanoscale. We focus on our group's research investigating the interaction between hydrogen gas and Pd nanoparticles, which presents an important model system for understanding both hydrogenation catalysis and hydrogen storage. The studies described in this Account primarily rely on an environmental transmission electron microscope, a tool capable of circumventing traditional TEM's high-vacuum requirements, outfitted with optical sources and detectors to couple light into and out of the microscope. First, we describe the H2 loading kinetics of individual Pd nanoparticles. When confined to sizes of less than ∼100 nm, single-crystalline Pd nanoparticles exhibit coherent phase transformations between the hydrogen-poor α-phase and hydrogen-rich β-phase, as revealed through monitoring the bulk plasmon resonance with electron energy loss spectroscopy. Next, we describe how contrast imaging techniques, such as phase contrast STEM and displaced-aperture dark field, can be employed as real-time techniques to image phase transformations with 100 ms temporal resolution. Studies of multiply twinned Pd nanoparticles and high aspect ratio Pd nanorods demonstrate that internal strain and grain boundaries can lead to partial hydrogenation within individual nanoparticles. Finally, we describe how OTEM can be used to locally probe nanoparticle dynamics under optical excitation and in reactive chemical environments. Under illumination, multicomponent plasmonic photocatalysts consisting of a gold nanoparticle "antenna" and a Pd "reactor" show clear α-phase nucleation in regions close to electromagnetic "hot spots" when near plasmonic antennas. Importantly, these hot spots need not correspond to the traditionally active, energetically preferred sites of catalytic nanoparticles. Nonthermal effects imparted by plasmonic nanoparticles, including electromagnetic field enhancement and plasmon-derived hot carriers, are crucial to explaining the site selectivity observed in PdHx phase transformations under illumination. This Account demonstrates how light can contribute to selective chemical phenomena in plasmonic heterostructures, en route to sustainable, solar-driven chemical production.

Role of Femtosecond Pulsed Laser-Induced Atomic Redistribution in Bimetallic Au-Pd Nanorods on Optoelectronic and Catalytic Properties.

Utilizing solar energy for chemical transformations has attracted a growing interest in promoting the clean and modular chemical synthesis approach and addressing the limitations of conventional thermocatalytic systems. Under light irradiation, noble metal nanoparticles, particularly those characterized by localized surface plasmon resonance, commonly known as plasmonic nanoparticles, generate a strong electromagnetic field, excited hot carriers, and photothermal heating. Plasmonic nanoparticles enabling efficient absorption of light in the visible range have moderate catalytic activities. However, the catalytic performance of a plasmonic nanoparticle can be significantly enhanced by incorporating a highly catalytically active metal domain onto its surface. In this study, we demonstrate that femtosecond laser-induced atomic redistribution of metal domains in bimetallic Au-Pd nanorods (NRs) can enhance its photocurrent response by 2-fold compared to parent Au-Pd NRs. We induce structure changes on Au-Pd NRs by irradiating them with a femtosecond pulsed laser at 808 nm to precisely redistribute Pd atoms on AuNR surfaces, resulting in modified electronic and optical properties and, thereby, enhanced catalytic activity. We also investigate the trade-off between the effect of light absorption and catalytic activity by optimizing the structure and composition of bimetallic Au-Pd nanoparticles. This work provides insight into the design of hybrid plasmonic-catalytic nanostructures with well-tailored geometry, composition, and structure for solar-fuel-based applications.

Plasmon-Mediated Nitrobenzene Hydrogenation with Formate as the Hydrogen Donor Studied at a Single-Particle Level

Hydrogenation of nitroaromatics is typically performed under harsh reaction conditions, which would bring safety issues and energy waste. The key for the hydrogenation reaction is to finely control the product selectivity under mild conditions. Herein, the anisotropic Pd–Au nanorods (NRs) exhibited efficient plasmon-enhanced selective hydrogenation of nitrobenzene to aniline with formate as the hydrogen donor. Under visible-light irradiation, both conversion and selectivity for nitrobenzene hydrogenation can reach nearly 100%. Plasmon-induced interaction between formic acid (FA), nitrobenzene, and plasmonic nanostructures was explored by single-particle photoluminescence (PL) measurement in situ. The complete quenching phenomenon of localized surface plasmon resonance PL for single Pd–Au NR was observed when immersed in FA. In addition, light-induced adsorption enhancement of nitrobenzene was discovered, which is vital for the plasmon-enhanced catalysis. This work provides direct evidence for the carrier transfer from Au–Pd NRs to FA via single-particle PL measurement and will give guidance to the rational design of hybrid plasmonic catalysts to promote eco-friendly organic conversion.

Electronic structure control over Pd nanorods by B, P-co-doping enables enhanced electrocatalytic performance

The popularization and commercialization of direct formic acid fuel cells require the development of superior electrocatalysts for formic acid oxidation reaction (FAOR). Herein, we report a ternary metal-metalloid-nonmetal PdBP catalyst that was fabricated via the co-doping of B and P elements into pre-synthesized Pd nanorods. Due to the coordinated enhancement of its rod-like structure and the doping of B and P, the structural and compositional advantages of ternary PdBP nanorods (PdBP NRs) can synergistically improve the electrocatalytic FAOR, achieving a mass activity of 1.32 mA μgPd−1 and a specific activity of 4.58 mA cm−2, which is superior to Pd NRs, PdB NRs, PdP NRs and commercial Pd black. This study may spotlight a compositional engineering avenue to develop newly advanced doped metal-based catalysts for electrocatalysis systems.

“Gold-plated” IRMOF-3 and sea cucumber-like Pd@PtRh SNRs based sandwich-type immunosensor for dual-mode detection of PCT

Electrochemical immunoassays are often used in the detection of biomarkers, and their sensitivity depends on the nature of the substrate and the catalytic activity of the signal amplification platform. In this work, a novel sandwich-type signal amplification strategy with a “gold-plated” organometallic frame (Au/IRMOF-3) as the substrate and the sea cucumber-like Pd@PtRh trimetallic nanomaterial (Pd@PtRh SNRs) as label was fabricated. For the substrate, gold nanoparticles (Au NPs) are stably connected to the free amino groups on the surface of organometallic frame (IRMOF-3), which not only prevent the agglomeration of Au NPs, but also greatly enhance the conductivity of the nanocomposites. The synergy between the two nanomaterials further shows a stronger affinity for the fixation of capture antibodies (Ab1). For the label, the effective high catalytic activity comes from the Pd@PtRh SNRs with a sea cucumber-like morphology. The nano-scale spherical PtRh crystals epitaxially grown on smooth Pd nanorods (Pd NRs) have more catalytically active sites because of the abundant edge and corner atoms, resulting in high catalytic activity and durability towards H2O2 reduction. Choosing calcitonin (PCT) as the target, differential pulse voltammetry (DPV) and amperometric i-t dual-mode detection was used to demonstrate the feasibility of the immunosensor. The results confirmed that the immunosensor exhibits excellent analytical capabilities and is satisfied in the analysis of human serum samples. Therefore, this strategy has great potential in the clinical application of electrochemical immunosensors.

Construction of coated Z-scheme Er3+:Y3Al5O12/Pd-CdS@BaTiO3 sonocatalyst composite for intensifying degradation of chlortetracycline hydrochloride in aqueous solution

A novel Er3+:Y3Al5O12/Pd-CdS@BaTiO3 composite is successfully fabricated as a coated Z-scheme sonocatalyst. The performance of the prepared Er3+:Y3Al5O12/Pd-CdS@BaTiO3 composite is investigated through chlortetracycline hydrochloride (CTC) degradation. The degradation ratio of CTC can reach 84.02% in the US/Er3+:Y3Al5O12/Pd-CdS@BaTiO3 system for 150 min. Moreover, some affecting factors such as ultrasonic irradiation time, catalyst dosage, initial CTC concentration and used times are considered. The experimental results indicated that the coated Z-scheme Er3+:Y3Al5O12/Pd-CdS@BaTiO3 sonocatalyst displayed outstanding sonocatalytic performance for the removal of CTC in aqueous media under ultrasonic irradiation. In Er3+:Y3Al5O12/Pd-CdS@BaTiO3 composite, CdS and BaTiO3 form a coated Z-scheme sonocatalytic system, some palladium (Pd) nanorods connecting BaTiO3 and CdS as conductive channels promote electrons transfer, effectively suppressing the recombination of electrons and holes pairs. Other some Pd nanorods as co-catalyst can transfer the electrons to its surface. The transferred electrons react with O2, producing O2−. And the BaTiO3 provides a large oxidization surface, which is conducive to CTC degradation. Besides, the up-conversion luminescent material (Er3+:Y3Al5O12) can increase the utilization of light. Finally, a possible sonocatalytic CTC degradation mechanism in the US/Er3+:Y3Al5O12/Pd-CdS@BaTiO3 system is proposed. Perhaps, the coated Er3+:Y3Al5O12/Pd-CdS@BaTiO3 composite is an applicable Z-scheme sonocatalyst to effectively treat the wastewater containing tetracycline under ultrasonic irradiation.

Pd-induced phase separation in poly(methyl methacrylate) telopolymer: synthesis of nanostructured catalytic Pd nanorods

Nanostructured palladium (Pd) is attractive for diverse applications owing to their unique properties compared to their bulk materials. Here, in this study, we have explored Pd-induced phase separation in functional sulfur containing poly(methyl methacrylate) telopolymer, which allowed synthesis of Pd nanorods with specific crystallographic facets. Pd nanorods were applied in water-mediated Suzuki coupling reaction of least reactive aryl chlorides with a quantitative yield of 99% under ambient laboratory conditions, free of phase-transfer agents. The origin of the high activity is ascribed to the highly active sites along the wavy Pd nanorod surface. The catalyst can be recycled and repeated over number of catalytic cycles.

Palladium nanostructures with well-controlled morphologies obtained by one-pot and one-step polyol method

The physical and chemical properties of metal nanomaterials are closely tied to their size and shape. A well-controlled synthesis protocol is needed to control over particle morphologies. Although the shape and size of metal nanostructures have been controlled by various pathways, such as soft templates and seed-mediated protocol method, most of the methods are involved with complicated multi-step synthesis. In this work, the morphology of palladium nanostructures, including nanorods, nanoparticles, and nanocubes, were well controlled by a simple one-step/one-pot polyol method in the presence of poly(vinylpyrrolidone) and KBr. A detailed study of the relationship between the morphology and controlling factors, such as reaction temperature, the concentration of metal precursor, PVP, reducing agent, and potassium bromide is presented. Well-controlled morphologies of Pd nanorods, nanospheres, and nanocubes are obtained via tuning these reaction parameters. The results from this work provide a basis for optimizing palladium nanocrystals growth through the simple one-pot/one-step polyol method.

High-Density Pd Nanorod Arrays on Au Nanocrystals for High-Performance Ethanol Electrooxidation.

In the synthesis of Au/Pd bimetallic nanocrystals, a layer-by-layer growth is favored, owing to the low bonding energy between Pd atoms ( EPd-Pd) in comparison with EAu-Pd, resulting in homogeneous core/shell nanostructures. Herein, we demonstrate designed synthetic tactics to unconventional Au/Pd heterostructures through a deposition-dominant growth pathway of the newly reduced Pd atoms, which break the intrinsically favored layer-by-layer growth. Pd thus grows on Au seeds in a heterogeneous nucleation manner. The resulting anisotropic Pd nanorods array on the two basal facets and three side facets of the Au triangular seeds in a high density to form 2D/1D Au/Pd heterostructures. It is noticed that Pd nanorods align in an extremely high order. They grow almost in a row with the base of the rod located overlapped on the Au surface. This versatile approach has been also applied to other Au nanocrystal seeds, involving hexagonal nanoplates, circular nanodisks, nanorods, and nanobipyramids. Furthermore, the 2D/1D Au/Pd heterostructures exhibit an enhanced electrocatalytic performance toward ethanol oxidation in alkaline condition, owing to their unique structure and the exposure of Au. We believe that our synthetic strategy is highly valuable for the construction of multimetallic nanostructures with desired architectures and thus intriguing properties.