Pt/Pd/Fe Trimetallic Nanoparticle Produced via Reverse Micelle Technique: Synthesis, Characterization, and Its Use as an Efficient Catalyst for Reductive Hydrodehalogenation of Aryl and Aliphatic Halides under Mild Conditions

Reticular framework materials for photocatalytic organic reactions

Photocatalytic organic reactions, harvesting solar energy to produce high value-added organic chemicals, have attracted increasing attention as a sustainable approach to address the global energy crisis and environmental issues. Reticular framework materials, including metal-organic frameworks (MOFs) and covalent organic frameworks (COFs), are widely considered as promising candidates for photocatalysis owing to their high crystallinity, tailorable pore environment and extensive structural diversity. Although the design and synthesis of MOFs and COFs have been intensively developed in the last 20 years, their applications in photocatalytic organic transformations are still in the preliminary stage, making their systematic summary necessary. Thus, this review aims to provide a comprehensive understanding and useful guidelines for the exploration of suitable MOF and COF photocatalysts towards appropriate photocatalytic organic reactions. The commonly used reactions are categorized to facilitate the identification of suitable reaction types. From a practical viewpoint, the fundamentals of experimental design, including active species, performance evaluation and external reaction conditions, are discussed in detail for easy experimentation. Furthermore, the latest advances in photocatalytic organic reactions of MOFs and COFs, including their composites, are comprehensively summarized according to the actual active sites, together with the discussion of their structure-property relationship. We believe that this study will be helpful for researchers to design novel reticular framework photocatalysts for various organic synthetic applications.

Synthesis of PVP-capped trimetallic nanoparticles and their efficient catalytic degradation of organic dyes

The study proposes a simple and efficient way to synthesize a heterogeneous catalyst that can be used for the degradation of organic dyes. A simple and fast chemical process was employed to synthesize Au: Ni: Co tri-metal nanohybrid structures, which were used as a catalyst to eliminate toxic organic dye contamination from wastewater in textile industries. The catalyst's performance was tested by degrading individual dyes as well as mixtures of dyes such as methylene blue (MB), methyl orange (MO), methyl red (MR), and Rose Bengal (RB) at various time intervals. The experimental results show the catalytic high degradation efficiency of different dyes achieving 72-90% rates in 29 s. Moreover, the material displayed excellent recycling stability, maintaining its degradation efficiency over four consecutive runs without any degradation in performance. Overall, the findings of the study suggest that these materials possess efficient catalytic properties, opening avenues toward their use in clean energy alternatives, environmental remediation, and other biological applications.

Functional materials contributing to the removal of chlorinated hydrocarbons from soil and groundwater: Classification and intrinsic chemical-biological removal mechanisms

Chlorinated hydrocarbons (CHs) are the main contaminants in soil and groundwater and have posed great challenge on the remediation of soil and ground water. Different remediation materials have been developed to deal with the environmental problems caused by CHs. Remediation materials can be classified into three main categories according to the corresponding technologies: adsorption materials, chemical reduction materials and bioaugmentation materials. In this paper, the classification and preparation of the three materials are briefly described in terms of synthesis and properties according to the different types. Then, a detailed review of the remediation mechanisms and applications of the different materials in soil and groundwater remediation is presented in relation to the various properties of the materials and the different challenges encountered in laboratory research or in the environmental application. The removal trends in different environments were found to be largely similar, which means that composite materials tend to be more effective in removing CHs in actual remediation. For instance, adsorbents were found to be effective when combined with other materials, due to the ability to take advantage of the respective strengths of both materials. The rapid removal of CHs while minimizing the impact of CHs on another material and the material itself on the environment. Finally, suggestions for the next research directions are given in conjunction with this paper.

Heterogeneous Trimetallic Nanoparticles as Catalysts

The development and application of trimetallic nanoparticles continues to accelerate rapidly as a result of advances in materials design, synthetic control, and reaction characterization. Following the technological successes of multicomponent materials in automotive exhausts and photovoltaics, synergistic effects are now accessible through the careful preparation of multielement particles, presenting exciting opportunities in the field of catalysis. In this review, we explore the methods currently used in the design, synthesis, analysis, and application of trimetallic nanoparticles across both the experimental and computational realms and provide a critical perspective on the emergent field of trimetallic nanocatalysts. Trimetallic nanoparticles are typically supported on high-surface-area metal oxides for catalytic applications, synthesized via preparative conditions that are comparable to those applied for mono- and bimetallic nanoparticles. However, controlled elemental segregation and subsequent characterization remain challenging because of the heterogeneous nature of the systems. The multielement composition exhibits beneficial synergy for important oxidation, dehydrogenation, and hydrogenation reactions; in some cases, this is realized through higher selectivity, while activity improvements are also observed. However, challenges related to identifying and harnessing influential characteristics for maximum productivity remain. Computation provides support for the experimental endeavors, for example in electrocatalysis, and a clear need is identified for the marriage of simulation, with respect to both combinatorial element screening and optimal reaction design, to experiment in order to maximize productivity from this nascent field. Clear challenges remain with respect to identifying, making, and applying trimetallic catalysts efficiently, but the foundations are now visible, and the outlook is strong for this exciting chemical field.

Continuous-flow syntheses of alloy nanoparticles

Alloy nanoparticles (NPs), including core-shell, segregated and solid-solution types, show a variety of attractive properties such as catalytic and optical properties and are used in a wide range of applications. Precise control and good reproducibility in the syntheses of alloy NPs are highly demanded because these properties are tunable by controlling alloy structures, compositions, particle sizes, and so on. To improve the efficiency and reproducibility of their syntheses, continuous-flow syntheses with various types of reactors have recently been developed instead of the current mainstream approach, batch syntheses. In this review, we focus on the continuous-flow syntheses of alloy NPs and first overview the flow syntheses of NPs, especially of alloy NPs. Subsequently, the details of flow reactors and their chemistry to synthesize core-shell, segregated, solid-solution types of alloy NPs, and high-entropy alloy NPs are introduced. Finally, the challenges and future perspectives in this field are discussed.

Revealing the Effect of MnO2, Activated Carbon and MnO2/Activated Carbon on Chitosan Polymer Host Fabricated Co NPs: Antibacterial Performance and Degradation of Organic Compounds

MnO₂ and MnO₂ blended with 1 and 2 weight percent of activated carbon (AC), MnO₂/AC1 and MnO₂/AC2 were synthesized through the sol–gel method. The pure chitosan (CS) films were cast in the form of films. Similarly, 5 weight% of each MnO₂, AC, MnO₂/AC1 and MnO₂/AC2 was intermingled with the CS to produce different films, such as CS-AC, CS-MnO₂, CS-MnO₂/AC1 and CS-MnO₂/AC2. Zero-valent Co NPs were then supported on these films through the chemical reduction method and expressed as CS@Co, CS-AC@Co, CS-MnO₂@Co, CS-MnO₂/AC1@Co and CS-MnO₂/AC2@Co NPs. All the catalysts were characterized by field emission scanning electron microscopy (FESEM), energy-dispersive spectroscopy (EDS) and X-ray diffraction (XRD) techniques. The synthesized catalysts were used as a dip catalyst against the hydrogenation of 4-nitrophenol (4NP), and for the degradation of methyl orange (MO) and Congo red (CR) dyes. The k_app and R² values were deduced from pseudo-first-order kinetics for 4NP and MO and zero-order kinetics for CR dye. The k_app values of CS-AC@Co and CS-MnO₂/AC1@Co NPs for 4NP hydrogenation were higher than those for any other member of the series, at 1.14 × 10⁻¹ and 1.56 × 10⁻¹ min⁻¹ respectively. Similarly, the rate of CR degradation was highest with CS-AC@Co. The R² values for 4NP, MO and CR dyes were above 0.9, which indicated that the application of pseudo-first- and zero-order models were appropriate for this study. Furthermore, the antibacterial activity of all the catalysts was evaluated against Pseudomonas aeruginosa and Escherichia coli. The CS-AC@Co NPs exhibited the highest zone of inhibition compared to other catalysts against P. aeruginosa, while all the catalysts were inactive against E. coli. This study reveals that the catalyst can be used for the degradation of other pollutants and for microbial inhibition.

Synthesis and potential applications of trimetallic nanostructures

The present review highlights the synthetic strategies and potential applications of TMNs for organic reactions, environmental remediation, and health-related activities.

A template of cellulose acetate polymer-ZnAl/C layered double hydroxide composite fabricated with Ni NPs: Applications in the hydrogenation of nitrophenols and dyes degradation

In this work, cellulose acetate polymer (CA) sheet and 2% ZnAl grafted on activated carbon grown in the form of layered double hydroxide (ZnAl/C-LDH) incorporated into CA polymer (CA-ZA2) 5 wt% (CA-ZA5) and 10 wt% of ZnAl/C-LDH (CA-ZA10) sheets were synthesized by simple casting method. All the stated sheets were fabricated with zero-valent Ni nanoparticles by adsorption of Ni⁺² ions followed by subsequent reduction with NaBH₄ and named as CA@Ni, CA-ZA2@Ni, CA-ZA5@Ni, and CA-ZA10@Ni NPs. The synthesized Ni NPs were investigated through FESEM, FTIR, XRD and EDS techniques. These supported and stabilized Ni NPs were largely used for the reduction of 4-nitrophenol (PNP), and 2-nitrophenol (ONP) in the presence of NaBH₄ which act as a reducing agent. Similarly, the catalytic efficiency was also assessed against the removal of dyes. The linear relationship and K_app were obtained from pseudo-first-order kinetics. The rate constant K_app of CA@Ni NPs for the reduction of PNP is 1.5 × 10^-1 and CA-ZA2@Ni (K_app = 2.6 × 10^-1), CA-ZA5@Ni (K_app = 3.2 × 10^-1), and CA-ZA10@Ni is 5.7 × 10^-1 min^-1. The highest rate constant for PNP reduction was observed with CA-ZA10@Ni NPs. The rate of CR removal with ZA10@Ni NPs is 2.05 × 10^-1 while the adjacent R² is 0.9013. Similarly, the rate constant and adjacent R² values were calculated for the degradation of other dyes and nitrophenols.

Synthesis, Properties, and Biological Applications of Metallic Alloy Nanoparticles

Metallic alloy nanoparticles are synthesized by combining two or more different metals. Bimetallic or trimetallic nanoparticles are considered more effective than monometallic nanoparticles because of their synergistic characteristics. In this review, we outline the structure, synthesis method, properties, and biological applications of metallic alloy nanoparticles based on their plasmonic, catalytic, and magnetic characteristics.

Composition and Solubilization of the Microemulsion Systems Containing Triton X-100: Effects of Aqueous Composition and Oil-Water-Ratios

The composition and solubilization of the optimum microemulsion systems containing Triton X-100/pentan-1-ol/aliphatic hydrocarbon/water were studied with the ∊-β fishlike phase diagram method. The solubilities of the alkanol (S A), the mass fractions of the alkanol in the interfacial layer (AS ) and the optimum solubilization parameters (SP∗) of the microemulsion systems with different aqueous phases (salt, acid, alkali) and with different α values were obtained and discussed. The SP∗ values increase significantly with the cation radius of the chlorides (NaCl, KCl, CsCl), but decrease slightly with the anion radius of the sodium halides (NaCl, NaBr, NaI). However, SP∗ values decrease with the increased salinities and NaOH contents. The trend was reversed for the acid systems. When the oil-water ratio (α) increases, the S A and A S values significantly increase, while the SP∗ values increase slowly. As the length of the carbon chain of the alkane molecules increases, both the S A and A S values increase, while the SP∗ values decrease significantly.

Photoactive Metal-Organic Framework for the Reduction of Aryl Halides by the Synergistic Effect of Consecutive Photoinduced Electron-Transfer and Hydrogen-Atom-Transfer Processes

Consecutive photoinduced electron transfer (ConPET) has advantages on overcoming the current energetic limitation of visible-light photoredox catalysis for utilizing the energies of two photons in one catalytic cycle. A heterogeneous approach for radical chain reduction of various aryl bromides and chlorides without adding any cocatalyst is introduced by incorporating polyoxometalates (POMs) and amine catalysts into a naphthalenediimide (NDI)-based polymer. CoW-DPNDI-PYI exhibits high activity in the photocatalytic reduction of aryl halides by the synergistic effects of ConPET and hydrogen-atom-transfer (HAT) processes and an enzyme-mimicking CO₂ cycloaddition reaction. The ConPET process with N,N'-bis(4-pyridylmethyl)naphthalenediimide (DPNDI) facilitates effective solar energy conversion. POMs and amine catalysts, as efficient HAT catalysts and electron donors, improve the generation of the ConPET process. The success of this work demonstrates the great application of the synergistic effects of ConPET and HAT processes in heterogeneous photocatalysis C-H arylation.

A mononuclear tantalum catalyst with a peroxocarbonate ligand for olefin epoxidation in compressed CO2

A mononuclear tantalum complex bonded to a peroxocarbonate ligand has been proved to be particularly important in the epoxidation reactions.

Supercritical flow synthesis of PtPdFe alloyed nanoparticles with enhanced low-temperature activity and thermal stability for propene oxidation under lean exhaust gas conditions

Supercritical flow technology was used for the one step production of PtPd and PtPdFe nanoparticles supported on high surface area γ-Al₂O₃.

The effect of different parameters under ultrasound irradiation for synthesis of new nanostructured Fe3O4@bio-MOF as an efficient anti-leishmanial in vitro and in vivo conditions

In this work, a magnetic bio-metal-organic framework (MBMOF) nanocomposite with porous-layer open morphology is synthesized through a simple sonochemical approach and its effects on Leishmania major (MRHO/IR/75/ER) under both in vitro and in vivo conditions are investigated. The effects of sonication time, initial concentration of reagents and sonication power on size and morphology of MBMOF nanocomposites have been investigated and optimized. A comparison was then made between the structural information of the nanostructures and that of the bio-metal-organic framework crystals. Using the powder X-ray diffraction (PXRD), field emission scanning electron microscope (FE-SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), energy dispersive analysis of X-ray (EDAX), vibrating sample magnetometer (VSM), thermogravimetric analysis (TGA), and Brunauer-Emmet-Teller (BET) techniques, the prepared MBMOF nanocomposites were characterized. The mean numbers of promastigotes (cell/ml) in different MBMOF concentrations (3.12, 6.25, 12.5, 25, 50, 100, 200 and 400 µg mL^-1) were determined by direct counting after 24, 48 and 72 h. Using MTT assays, the cytotoxic impacts of the MBMOF nanocomposites on promastigotes, intracellular amastigotes, and J774 macrophages were estimated. In order to investigate their therapeutic effects, the prepared MBMOF nanocomposites (25 and 12.5 µg mL^-1) were used as ointment three times a week to treat Leishmania major in BALB/c mice. The lesion size and weight of mice were assessed before and during the treatment. The parasitic loads were measured in spleen and liver through the culture. After 72 h, the INF-γ and IL-4 cytokines levels in the supernatant of the spleen culture were measured. To the best of the authors' knowledge, this study is the first to attempt to synthesize the bio-MOFs through an in-situ sonosynthesis route under ultrasound irradiation and examine their cytotoxicity effects on Leishmania major under in vitro and in vivo conditions.

Mechanism, synthesis and modification of nano zerovalent iron in water treatment

Owing to its strong reducing ability, high reaction activity, excellent adsorption properties, good mobility and relatively low cost, nano zerovalent iron (nZVI) is an extremely promising nanomaterial for use in water treatment. In this paper, the working mechanisms of nZVI in the degradation of various contaminants in water are outlined and discussed. Synthesis methods and their respective advantages and disadvantages are discussed in detail. Furthermore, a variety of modification methods which have been developed to improve the mobility and stability of nZVI as well as to facilitate the separation of nZVI from degraded systems are also summarized and discussed. Numerous studies indicate that nZVI has considerable potential to become an efficient, versatile and practical approach for large-scale water treatment.

Comparative study on catalytic hydrodehalogenation of halogenated aromatic compounds over Pd/C and Raney Ni catalysts

Catalytic hydrodehalogenation (HDH) has proved to be an efficient approach to dispose halogenated aromatic compounds (HACs). Liquid-phase HDH of single and mixed halobenzenes/4-halophenols with H₂ over 5% Pd/C and Raney Ni catalyst are investigated and compared. For liquid-phase HDH of single HACs, hydrogenolytic scission reactivity of C-X bonds decreases in order of C-Br > C-Cl > C-I > C-F over Pd/C catalyst, and in order of C-I > C-Br > C-Cl > C-F over Raney Ni catalyst. To clarify the reason why hydrogenolytic scission reactivity of C-X bonds over Pd/C and Raney Ni catalysts exhibits different trends, liquid-phase HDH of mixed HACs over Pd/C and Raney Ni catalysts were studied, and catalysts are characterized by SEM, EDX, and XRD techniques. It was found that the high adsorption of iodoarenes on Pd/C catalyst caused the HDH reactivity of iodoarenes to be lower than that of chloroarenes and bromoarenes in the HDH of single HACs. Moreover, the adsorption of in situ produced iodine ion (I⁻) to catalyst surface would result in the decline of catalytic activity, which might be the main reason why the HDH reactivity of HACs in the presence of NaI is rather low.

Improved sensitivity via layered-double-hydroxide-uniformity-dependent chemiluminescence

In the last two decades nanoparticles have been widely applied to enhance chemiluminescence (CL). The morphology of nanoparticles has an important influence on nanoparticle-amplified CL. However, studies of nanoparticle-amplified CL focus mainly on the size and shape effects, and no attempt has been made to explore the influence of uniformity in nanoparticle-amplified CL processes. In this study we have investigated nanoparticle uniformity in the luminol-H₂O₂ CL system using layered double hydroxides (LDHs) as a model material. The results demonstrated that the uniformity of LDHs played a key role in CL amplification. A possible mechanism is that LDHs with high uniformity possess abundant catalytic active sites, which results in high CL intensity. Meanwhile, the sensitivity for H₂O₂ detection was increased by one order of magnitude (1.0 nM). Moreover, the uniform-LDH-amplified luminol CL could be applied to selective detection of glucose in human plasma samples. Furthermore, such a uniformity-dependent CL enhancement effect could adapted to other redox CL systems-for example, the peroxynitrous acid (ONOOH) CL system.

Transfer hydrodehalogenation of aryl halides accelerated by a saturated sodium acetate aqueous solution

A saturated sodium acetate aqueous solution could be applied as an efficient and environmentally-friendly reaction medium to accelerate transfer hydrodehalogenation of various aryl halides.

A facile one-step route for production of CuO, NiO, and CuO–NiO nanoparticles and comparison of their catalytic activity for ammonium perchlorate decomposition

This study demonstrates a straightforward, inexpensive, high-yield, and ecofriendly route for synthesis of sphere-like CuO, NiO, and CuO–NiO (with different molar ratios) nanoparticles (NPs) through emulsion route.

Synthesis of an Fe rich amorphous structure with a catalytic effect to rapidly decolorize Azo dye at room temperature

In this article, an amorphous Fe rich amorphous structure designed based on a competitive atomic cluster model was synthesized and characterized successfully. The constituent zero-valent iron (ZVI) has excellent activity and efficiency for decolorization of Orange G (OG) solution at room temperature. The decolorization is characterized by UV-vis spectrum and pseudo-first-order kinetics. The X-ray Micro fluorescence spectrometer, Inductively Coupled Plasma Optical Emission Spectrometry, and Scanning Electron Microscope were employed to trace the ZVI. The consumption of ZVI destabilizes the local atomic arrangement and yields the phase separation of Fe at the surface and responds to the high activity and the catalysis for decolorization. This observation is in accordance with the change of k1 0.011 min(-1) to k2 0.047 min(-1), which is supported by the cyclic decolorization test. This work provides a new strategy to design multifunctional metal materials and indicates their brilliant future in practical applications.

Formation of dispersed palladium–nickel bimetallic nanoparticles in microemulsions: synthesis, characterization, and their use as efficient heterogeneous recyclable catalysts for the amination reactions of aryl chlorides under mild conditions

The amination cross-coupling reaction by Pd–Ni (1 : 1) bimetallic nanoparticles in water solvent.

In situ synthesis of Au–Pd bimetallic nanoparticles on amine-functionalized SiO2 for the aqueous-phase hydrodechlorination of chlorobenzene

The homogeneous Au–Pd NPs have been prepared through a facile in situ reduction method. The optimal AuPd_1.0/SiO₂ catalyst could complete the conversion of chlorobenzene due to the high dispersion and modified electronic properties of Pd.

A facile and efficient preparation of anatase titania nanoparticles in micelle nanoreactors: morphology, structure, and their high photocatalytic activity under UV light illumination

Comparative photocatalysis degradation of MB dye under ultraviolet light irradiation: (a) without photocatalyst; (b) commercial P25 TiO₂ powder; and (c) TiO₂ nanoparticles.