Loading Of Metal Nanoparticles Research Articles

Polydopamine-Modified Polycaprolactone Scaffolds Loading Metal Nanoparticles for Bone Tissue Engineering.

Recent advancements in materials synthesis and processing technology, coupled with a deeper understanding of bone nanoscale structure and biology, have provided new avenues for designing bioactive materials in bone tissue regenerative medicine. This Review focuses on the design and application of polydopamine-modified polycaprolactone scaffolds loading metal nanoparticles for bone tissue engineering. We explore their antibacterial properties and their ability to guide cell behavior. Specifically, we discuss the synthesis techniques, protein deposition, morphology variations, and interactions with the extracellular matrix of these scaffolds and biocompatibility and efficacy in promoting bone tissue regeneration in vitro and in vivo. Challenges and unmet needs are reviewed in the development of polymer- and metal-based materials for bone tissue engineering.

Glassy Carbon Electrodes Modified with Ru Nanoparticles Loaded in B-Doped Imidazolium Porous Organic Polymers for Hydrogen Evolution Reaction.

Porous organic polymers (POPs) are a type of porous material composed of organic structural units connected by covalent bonds and POPs have been used as efficient electrocatalysts for hydrogen evolution reaction (HER). Herein, glassy carbon electrode (GCE) is chemically modified by B-doped imidazolium-based porous organic polymers loaded with Ru nanoparticles on the GCE surface. The incorporation of B in the POPs regulates the electronic structure of electrocatalysts to enhance their inherent electrocatalytic activity for HER. The optimized modified electrode GCE-Ru/PIM-Br2 exhibits a low overpotential of 271 mV at a current density of 10 mA cm-2 with a small Tafel slope (80 mV dec-1) in acidic solutions, and shows long-term stability for up to 22 h. This work presents a strategy to develop B-doped porous electrodes with loaded metal nanoparticles to strengthen the catalytic performance of electrocatalysts.

Platinum-ruthenium-iron embedded in nitrogen-doped ordered mesoporous carbon for adrenaline electrochemical sensing study.

A novel nitrogen-doped ordered mesoporous carbon (OMC) pore-embedded growth Pt-Ru-Fe nanoparticles (Pt1-Ru7.5-Fex@N-OMCs) composite was designed and synthesized for the first time. SBA-15 was used as a template, and dopamine was used as a carbonandnitrogen source and metal linking reagent. The oxidative self-polymerization reaction of dopamine was utilized to polymerize dopamine into two-dimensional ordered SBA-15 template pores. Iron porphyrin was introduced as an iron source at the same time as polymerization of dopamine, which was introduced inside and outside the pores using dopamine-metal linkage. Carbonization of polydopamine, nitrogen doping and iron nanoparticle formation were achieved by one-step calcination. Then the templates were etched to form Fex@N-OMCs, and finally the Pt1-Ru7.5-Fex@N-OMCs composites were stabilized by the successful introduction of platinum-ruthenium nanoparticles through the substitution reaction. The composite uniformly embeds the transition metal nanoparticles inside the OMC pores with high specific surface area, which limits the size of the metal nanoparticles inside the pores. At the same time, the metal nanoparticles are also loaded onto the surface of the OMCs, realizing the uniform loading of metal nanoparticles both inside and outside the pores. This enhances the active sites of the composite, promotes the mass transfer process inside and outside the pores, and greatly enhances the electrocatalytic performance of the catalyst. The material shows high electrocatalytic performance for adrenaline, which is characterized by a wide linear range, high sensitivity and low detection limit, and can realize the detection of actual samples.

Lignin-functionalized cobalt for catalytic reductive degradation of organic dyes in simple and hybrid binary systems

To fulfill the unprecedented valorization approaches for lignocellulose, this work focuses on the potential of lignin-derived catalytic systems for bio-remediation, which are natural materials perceived to address the increased demand for eco-conscious catalyzed processes. A useful lignin-functionalized cobalt (Lig-Co) catalyst has been prepared, well-characterized and deployed for the catalyzed reducing decomposition of stable harmful organic pollutants such as methylene blue (MB) and methyl orange (MO), in simple and binary systems. The multifunctional character of lignin and the presence of various active sites can promote effectively loaded metal nanoparticles (NPs). Considerably, optimizing detoxification tests showed that the uncatalyzed use of NaBH4 as a reductive agent led to an incomplete reduction of organic contaminants over a long period of up to 65 min. Interestingly, Lig-Co catalyst exhibited a high reduction rate and turnover frequency of up to 99.23% and 24.12 min−1 for MB, respectively, while they reached 99.25% and 26.21 min−1 for MO at normal temperature. Kinetically quick catalytic reaction was also demonstrated for the hybrid system, in which the rate constant k was 0.175 s−1 and 0.165 s−1 for MB and MO, respectively, within a distinctly low reaction time of around 120 s. The reproducibility of the Lig-Co catalyst induces a desirable capacity to reduce stable dyes present simultaneously in the binary system, with 6 successive catalytic runs and over 80% of activity retained. Such robust findings underline the considerable interest in developing future lignin-mediated catalytic transformations and upscaling biomass-derived products, to meet the growing demand for sustainable and eco-friendly alternatives in various industries.

Electrodeposition of gold-platinum nanoparticles on 2D M-TCPP (M = Co, Cu, Zn) for electrochemical monitoring of H2O2 from living cells

Two-dimensional (2D) metal–organic frameworks (MOFs) as supporting nanomaterials to encapsulate or load metal nanoparticles have been widely applied in electrochemical sensing. Therefore, the influences of tetrakis(4-carboxyphenyl) porphyrin-based MOFs (M-TCPP (M = Co, Cu, Zn)) as supporting materials on the electrocatalytic activity were studied. A surfactant-assisted method was employed to facilely synthesize three types of 2D M-TCPP nanosheet MOFs. Polyvinylpyrrolidone was selected as a surfactant for preparing M-TCPP and played a key role in the controlled anisotropic growth of MOF crystals, resulting in the formation of 2D MOF nanosheets. Then, one-step electrodeposition of gold-platinum nanoparticles (AuPt NPs) on the M-TCPP-modified glassy carbon electrode (AuPt/M-TCPP/GCE) was explored for reducing hydrogen peroxide (H2O2). Cyclic voltammetry was applied to investigate the electrocatalytic performance of AuPt/M-TCPP/GCE, and AuPt/Cu-TCPP/GCE exhibited better electrocatalytic characteristics than AuPt/Co-TCPP/GCE and AuPt/Zn-TCPP/GCE. The electrochemical H2O2 sensor displayed a low detection limit of 3.1 nM in the wide concentration range of 0.01 μM to 80 mM. In addition, the proposed sensor showed high stability, good reproducibility, and selectivity. Moreover, HepG2 human liver cancer cells were selected for real-time detection of H2O2 to verify the feasibility of this technology for the evaluation of anticancer drugs. The results showed that Cu-TCPP can be used as an efficient supporting material for enhancing the detection property of electrochemical sensors.

Fe nanoparticles confined by multiple-heteroatom-doped carbon frameworks for aqueous Zn-air battery driving CO2 electrolysis

Metal-organic frameworks (MOF) derived carbon materials are considered to be excellent conductive mass transfer substrates, and the large specific surface area provides a favorable platform for loading metal nanoparticles. Tuning the coordination of metals through polyacid doping to change the MOF structure and specific surface area is an advanced strategy for designing catalysts. Modification of Fe-doped ZIF-8 pre-curing by pyrolysis of phosphomolybdic acid hydrate (PMo), Fe nanoparticles confined by Mo and N co-doped carbon frameworks (Fe-NP/MNCF) were fabricated, and the impact of PMo doping on the shape and functionality of the catalysts was investigated. The Zn-air battery (ZAB) driven CO2 electrolysis was realized by using Fe-NP/MNCF, which was used as bifunctional oxygen reduction reaction (ORR) and carbon dioxide reduction reaction (CO2RR) catalysts. The results show that the half-wave potential (E1/2) of Fe-NP/MNCF is 0.89 V, and the limiting diffused current density (jL) is 6.4 mA cm−2. The ZAB constructed by Fe-NP/MNCF shows a high specific capacity of 794.8 mAh gZn−1, a high open-circuit voltage (OCV) of 1.475 V, and a high power density of 111.6 mW cm−2. Fe-NP/MNCF exhibited efficient CO2RR performance with high CO Faraday efficiency (FECO) of 87.5 % and current density for the generation of carbon dioxide (jCO) of 10 mA cm−2 at −0.9 V vs RHE. ZAB-driven CO2RR had strong catalytic stability. These findings provide new methods and techniques for the preparation of advanced carbon-based catalysts from MOFs.

Two-Photon Polymerization Printing with High Metal Nanoparticle Loading.

Two-photon polymerization (2PP) is an efficient technique to achieve high-resolution, three-dimensional (3D)-printed complex structures. However, it is restricted to photocurable monomer combinations, thus presenting constraints when aiming at attaining functionally active resist formulations and structures. In this context, metal nanoparticle (NP) integration as an additive can enable functionality and pave the way to more dedicated applications. Challenges lay on the maximum NP concentrations that can be incorporated into photocurable resist formulations due to the laser-triggered interactions, which primarily originate from laser scattering and absorption, as well as the limited dispersibility threshold. In this study, we propose an approach to address these two constraints by integrating metallic Rh NPs formed ex situ, purposely designed for this scope. The absence of surface plasmon resonance (SPR) within the visible and near-infrared spectra, coupled with the limited absorption value measured at the laser operating wavelength (780 nm), significantly limits the laser-induced interactions. Moreover, the dispersibility threshold is increased by engineering the NP surface to be compatible with the photocurable resin, permitting us to achieve concentrations of up to 2 wt %, which, to our knowledge, is significantly higher than the previously reported limit (or threshold) for embedded metal NPs. Another distinctive advantage of employing Rh NPs is their role as promising contrast agents for X-ray fluorescence (XRF) bioimaging. We demonstrated the presence of Rh NPs within the whole 2PP-printed structure and emphasized the potential use of NP-loaded 3D-printed nanostructures for medical devices.

Design of Hollow Nanoreactors for Size- and Shape-Selective Catalytic Semihydrogenation Driven by Molecular Recognition.

Mimicking the structures and functions of cells to create artificial organelles spurs the development of efficient strategies for producing hollow nanoreactors with biomimetic catalytic functions, but it is still rarely reported because of the highly challenging fabrication. Here, we report the design of hollow nanoreactors with hollow multishelled structure (HoMS) and spatially loaded metal nanoparticles. Starting from molecular-level design strategy, well-defined hollow multishelled structure phenolic resins (HoMS-PR) and carbon (HoMS-C) submicron particles were accurately architected. HoMS-C can serve as an excellent, versatile platform, owing to its tunable properties with tailored functional sites, for achieving precise spatial location of metal nanoparticles, internally encapsulated (Pd@HoMS-C) or externally supported (Pd/HoMS-C). Impressively, the combination of the delicate nanoarchitecture and spatially loaded metal nanoparticles endow the pair of nanoreactors size-shape-selective molecular recognition properties in catalytic semihydrogenation, including high activity and selectivity of Pd@HoMS-C for small aliphatic substrates and Pd/HoMS-C for large aromatic substrates. Theoretic calculation provides insights into the pair of nanoreactors with distinct behaviors due to the differences in energy barrier of substrate adsorption. This work shed the light on rational design and accurate construction of hollow nanoreactors with precise location of active sites and fine-modulated microenvironment by mimicking the functions of cells.

Design of Hollow Nanoreactors for Size‐ and Shape‐Selective Catalytic Semihydrogenation Driven by Molecular Recognition

AbstractMimicking the structures and functions of cells to create artificial organelles has spurred the development of efficient strategies for production of hollow nanoreactors with biomimetic catalytic functions. However, such structure are challenging to fabricate and are thus rarely reported. We report the design of hollow nanoreactors with hollow multishelled structure (HoMS) and spatially loaded metal nanoparticles. Starting from a molecular‐level design strategy, well‐defined hollow multishelled structure phenolic resins (HoMS‐PR) and carbon (HoMS‐C) submicron particles were accurately constructed. HoMS‐C serves as an excellent, versatile platform, owing to its tunable properties with tailored functional sites for achieving precise spatial location of metal nanoparticles, internally encapsulated (Pd@HoMS‐C) or externally supported (Pd/HoMS‐C). Impressively, the combination of the delicate nanoarchitecture and spatially loaded metal nanoparticles endow the pair of nanoreactors with size–shape‐selective molecular recognition properties in catalytic semihydrogenation, including high activity and selectivity of Pd@HoMS‐C for small aliphatic substrates and Pd/HoMS‐C for large aromatic substrates. Theoretical calculations provide insight into the pair of nanoreactors with distinct behaviors due to the differences in energy barrier of substrate adsorption. This work provides guidance on the rational design and accurate construction of hollow nanoreactors with precisely located active sites and a finely modulated microenvironment by mimicking the functions of cells.

Loading metal nanoparticles on the CoAl-LDH/CGCNN S-scheme heterojunction for efficient photocatalytic CO2 reduction under visible light

Converting CO2 into high-value products by photocatalysis can alleviate the global greenhouse effect and energy crisis. In this work, CoAl-LDH/CGCNN-Metal NPs (AC-M) ternary photocatalysts were synthesized by calcination, hydrothermal, and ultrasonic self-assembly methods. In pure water, the best sample AC-Au could convert CO2 into CO, CH4, C2H4, and C2H6 with the yields of 5.93, 17.68, 1.25 and 2.15 µmol g−1h−1, respectively, and exhibited good stability within 5 cycles (30 h). The synergistic effect between S-scheme heterojunction and metal NPs could broaden the composite's photo-response range and promote the separation of photogenerated carriers. Furthermore, the metal NPs could also serve as the electron-rich centers to improve the chemisorption of CO2 and convert it into C1 and C2 products under visible light. This work can provide meaningful guidance for studying the efficient reduction of CO2 to C1 and C2 products by S-scheme heterojunction/metal NPs ternary photocatalytic system.

Electrocatalytic reduction of nitrate by copper/iron oxides supported on nitrogen doped carbon spheres

In recent years, electrocatalytic reduction has gained attention as a promising method for environmentally friendly nitrate treatment. The key to this approach is finding cathode materials with high activity, N2 selectivity, and stability. Researchers are therefore focused on creating efficient catalysts. In this study, nitrogen-doped carbon spheres (NMCS) loaded with Cu and Fe3O4 were synthesized from non-precious metals Fe and Cu and tested for nitrate reduction in water. The bimetal combination effectively reduces the formation of toxic NO2− intermediates and improves material impedance, accelerating electron transfer during the reaction. The mesoporous structure with high surface area also supports metal nanoparticle loading and reduces metal leaching during the process. The resulting Cu/Fe-NMCS-1–3 catalysts showed excellent NO3− reduction (97.04%) and 100% N2 selectivity using electrochlorination. After four cycles, no decline in electrocatalytic performance was observed, suggesting good stability and potential for electrocatalytic nitrate removal.

Temperature Responsive Diblock Polymer Brushes as Nanoreactors for Silver Nanoparticles Catalysis.

Metal nanoparticles are widely used in catalysis. Loading metal nanoparticles into polymer brushes has aroused wide attention, but regulation of catalytic performance still needs to be improved. The novel diblock polymer brushes, polystyrene@sodium polystyrene sulfonate-b-poly (N-isopropylacrylamide) (PSV@PSS-b-PNIPA) and PSV@PNIPA-b-PSS with reversed block sequence, were prepared by surface initiated photoiniferter-mediated polymerization (SI-PIMP) and used as nanoreactors to load silver nanoparticles (AgNPs). The block sequence caused the difference of conformation and further affected the catalytic performance. PSV@PNIPA-b-PSS@Ag was found to be able to control the amount of AgNPs exposed to external reactant of 4-nitrophenol at different temperatures to achieve regulation of the reaction rate due to the hydrogen bonds and further physical crosslinking between PNIPA and PSS.

Silver Nanoparticles Anchored on Single-Walled Carbon Nanotubes via a Conjugated Polymer for Enhanced Sensing Applications.

Single-walled carbon nanotubes (SWCNTs) are candidate matrices for loading metal nanoparticles (NPs) for sensor and catalytic applications owing to their high electron conductivity and mechanical strength, larger surface area, excellent chemical stability, and ease of surface modification. The performance of the formed NP/SWCNT composites is dependent on the NP size, the physical and chemical interactions between the components, and the charge transfer capabilities. Anchoring metal complexes onto the surface of SWCNTs through noncovalent interactions is a viable strategy for achieving high-level metal dispersion and high charge transfer capacities between metal NPs and SWCNTs. However, traditional metal complexes have small molecular sizes, and their noncovalent interactions with SWCNTs are limited to provide excellent sensing and catalytic capability with restricted efficiency and durability. Here, we selected poly(9,9-di-n-dodecylfluorenyl-2,7-diyl-alt-2,2'-bipyridine-5,5') (PFBPy) to increase the noncovalent interactions between silver nanoparticles (AgNPs) and SWCNTs. A silver triflate (Ag-OTf) solution was added into a PFBPy-wrapped SWCNT solution to form Ag-PFBPy complexes on the nanotube surface, after which Ag+ was photoreduced to AgNPs to form a Ag-PFBPy/SWCNT composite in the solution. In various feeding molar ratios of Ag-OTf over the BPy unit (0.4-50), the size of the formed AgNPs may be well-controlled at sub-nm levels to provide them with an energy level comparable to that of the SWCNTs. Additionally, the 2,2'-bipyridine (BPy) unit of the polymer provided a coordinating interaction with Ag+ and the formed AgNPs as well. The 5,5'-linage of BPy with the fluorene unit in PFBPy ensured a straight main chain structure to retain strong π-π interactions with nanotubes before and after Ag+ chelation. All of these factors confirmed a tight contact between the formed AgNPs and SWCNTs, promoting the charge transfer between them and enhancing the sensing capabilities with a 5-fold increase in humidity sensing sensitivity.

Chitosan hydrogel anchored phthalocyanine supported metal nanoparticles: Bifunctional catalysts for pollutants reduction and hydrogen production

Metal nanoparticles possess high catalytic activity in various organic transformation reactions. A catalyst must be recovered and re-used effectively and economically to lower the overall reaction cost. The recovery of a catalyst remains a challenge due to their extreme small size. In this research work, catalytic metal nanoparticles were synthesized on Zn-phthalocyanine (ZnPc) and chitosan hydrogel (CH) composite which acts as catalyst support. The ZnPc-CH support facilitate the easy recovery of the loaded metal nanoparticles. Metal nanoparticles (M0) based on Cu0, Ag0, Ni0, Co0 and Fe0 were decorated inside and on ZnPc-CH hydrogel surface. The developed M0@ZnPc-CH were utilized for the enhanced selective reduction of toxins and hydrogen production by methanolysis and hydrolysis of NaBH4. Effective catalytic reduction and hydrogen generation was successfully achieved with Co0@ZnPc-CH and ZnPc-CH. Under optimized conditions, Co0@ZnPc-CH showed complete reduction of 4-nitrophenol (4-NP) in 8.0 min with the fast 4-NP reduction kinetics (K = 0.611 min−1). Among the developed catalysts, ZnPc-CH showed fast H2 generation with high H2 generation rate (HGR = 4100 mLg−1min−1) under optimized conditions. Metal leaching from Co0@ZnPc-CH was negligible during recycling of the catalyst, suggesting that it could be implemented to 4-NP treatment from real water samples. Similarly, ZnPc-CH could produce same quantity of H2 throughout 4 continuous cycles of durability testing without any deactivation and leaching and ZnPc-CH showed high stability, indicating the effectiveness of the catalyst to be applied for H2 production on large scale.

Noble Metal Nanoparticle-Loaded Porphyrin Hexagonal Submicrowires Composites (M-HW): Photocatalytic Synthesis and Enhanced Photocatalytic Activity.

Surface plasmon resonance (SPR) photocatalysts have attracted considerable attention because of their strong absorption capacity of visible light and enhanced photogenic carrier separation efficiency. However, the separate production of metal nanoparticles (NPs) and semiconductors limits the photogenic charge transfer. As one of the most promising organic photocatalysts, porphyrin self-assemblies with a long-range ordered structure-enhance electron transfer. In this study, plasmonic noble metal-based porphyrin hexagonal submicrowires composites (M-HW) loaded with platinum (Pt), silver (Ag), gold (Au), and palladium (Pd) NPs were synthesized through a simple in situ photocatalytic method. Homogeneous and uniformly distributed metal particles on the M-HW composites enhanced the catalytic or chemical properties of the organic functional nanostructures. Under the same loading of metal NPs, the methyl orange photocatalytic degradation efficiency of Ag-HW [kAg-HW (0.043 min-1)] composite was three times higher than that of HW, followed by Pt-HW [kPt-HW (0.0417 min-1)], Au-HW [kAu-HW (0.0312 min-1)], and Pd-HW [kPd-HW (0.0198 min-1)]. However, the rhodamine B (RhB) and eosin B photocatalytic degradations of Pt-HW were 4 times and 2.6 times those of HW, respectively. Finally, the SPR-induced electron injection, trapping, and recombination processes of the M-HW system were investigated. These results showed that M-HW plasmonic photocatalysts exhibited excellent photocatalytic performances, making them promising materials for photodegrading organic pollutants.

Voltage-driven reduction method to optimize in-situ exsolution of Fe nanoparticles at Sr2Fe1.5+xMo0.5O6-δ interface

Improving the catalytic activity of perovskite electrodes by loading metal nanoparticles through interface engineering is one of the research hotspots in the field of CO2 electrolysis in solid oxide electrolytic cell (SOEC). The challenge is to improve the stability and carbon resistance of the metal-oxide interface while reducing time costs and improving scalability. We used applied voltage-driven reduction and non-stoichiometric doping to make Fe nanoparticles uniformly and firmly anchored on the surface of Sr2Fe1.5+xMo0.5O6-δ (SF1.5+xM, x = 0, 0.025, 0.05, 0.075, 0.1) within 180 s, optimized the distribution of Fe nanoparticles on the surface of SF1.5+xM, and thus constructed a metal-oxide interface with high activity and high stability, effectively preventing the sintering and carbon deposition of metal particles. When the electrode composition is SF1.575 M, the CO yield is 4.0 mL·min-1·cm-2, while the polarization impedance is 0.155 Ω·cm-2, at 850 °C, 1.6 V. It can be said that voltage-driven reduction is an effective and efficient method applied to interface engineering.

Mn‐Modified Graphitic Carbon Nitride‐Supported Bimetallic PtNi Nanoparticles for Hydrogen Generation from Hydrous Hydrazine

AbstractMn‐modification, as a method of material element modification, has a vital efficacy on the structure of materials, providing abundant active sites for the loading of metal nanoparticles. Herein, highly dispersed PtNi nanoparticles deposited on Mn‐modified graphitic carbon nitride (g‐C3N4) was synergistically constructed by a facile and valid impregnation reduction method. Interestingly, among all the tested samples, the obtained Pt0.6Ni0.4/(MnOx)2‐C3N4 display perfect catalytic activity towards decomposition of hydrous hydrazine to produce hydrogen in alkaline solution, with the value of turnover frequency (TOF) is 2749 h−1 at 323 K. Simultaneously, the as‐synthetic catalyst remains outstanding hydrogen selectivity and stability after five recycles. This work proposes a novel strategy for structural modification catalysts to enhance the catalytic performance for dehydrogenation of hydrous hydrazine.

Silver nanoparticle-decorated 2D Co-TCPP MOF nanosheets for synergistic photodynamic and silver ion antibacterial

Two-dimensional (2D) metal organic framework (MOF) nanosheets have been demonstrated to be promising templates for preparing functional 2D composites. Herein, we report the preparation of silver nanoparticle (Ag NP)-decorated 2D porphyrinic MOF nanosheets (denoted as Ag/Co-TCPP NSs) with a high efficiency for combined antibacterial therapy. The as-prepared Ag/Co-TCPP NSs feature both the advantages of Co-TCPP NSs and Ag NPs, which exhibit excellent antibacterial properties against both Gram-positive (S. aureus) and Gram-negative (E. coli) bacteria. Under a 660 nm laser irradiation, Ag/Co-TCPP NSs locally generated singlet oxygen (1O2) and promoted Ag NPs to be partly degraded for sustained release of toxic Ag+, achieving a synergistic sterilization effect. This effective strategy for achieving 2D MOF nanosheets with in situ loaded metal nanoparticles provides a guideline to broaden the diverse applications of MOFs and contributes to the development of new intelligent metal-based antibacterial nanomaterials.

Spherical covalent organic framework supported Cu/Ag bimetallic nanoparticles with highly catalytic activity for reduction of 4-nitrophenol

4-Nitrophenol (4-NP) is water pollutant with good stability, high toxicity and difficult degradation, which will cause great harm to the environment. Thus, the development of high efficiency and rapid catalysts for the degradation of 4-NP will be an urgent problem to be solved. Herein, we synthesized covalent organic framework supporting Cu/Ag bimetallic nanoparticles (Cu/Ag–COF), which had better catalytic activity for the reduction of 4-NP. The porous COF possess large surface area of approximately 737.8 ​m2/g, so it can provide abundant sites for loading metal nanoparticles. At the same time, COF could also improve the stability and catalytic effect of nanocatalyst under flexible condition. The prepared Cu/Ag–COF exhibited the higher catalytic reduction of 4-NP into 4-aminophenol (4-AP) under the condition that the molar ratio of NaBH4 to 4-NP was 147 and achieved an apparent rate constant of kCu/Ag–COF ​= ​0.0073 s−1. The apparent rate constant of Cu/Ag–COF was higher than that of Ag–COF (kAg-COF ​= ​0.0032 s−1) and Cu–COF (kCu-COF ​= ​0.0047 s−1), indicating that this system had a synergistic catalytic effect to improve the catalytic activity of metal nanoparticles. Moreover, Cu/Ag–COF still had good catalytic effect after eight cycles, which indicated that it had good stability and reusability. This work provides a novel strategy to fabricate COF supported nanoparticles for outstanding performance in treating wastewater containing 4-NP.

Self-Assembly Ultrathin Fe-Terephthalic Acid as Synergistic Catalytic Platforms for Selective Hydrogenation

Self-Assembly Ultrathin Fe-Terephthalic Acid as Synergistic Catalytic Platforms for Selective Hydrogenation