CuNi Bimetallic Nanoparticles Research Articles

Bimetallic CuNi Nanoparticle Formation: Solution Combustion Synthesis and Molecular Dynamic Approaches.

Nanomaterials are vital in catalysis, sensing, energy storage, and biomedicine and now incorporate multiprincipal element materials to meet evolving technological demands. However, achieving a uniform distribution of multiple elements in these nanomaterials poses significant challenges. In this study, various Cu-Ni compositions were used as a model system to investigate the formation of bimetallic nanoparticles by employing computer simulation molecular dynamics methods and comparing the results with observations from solution-combustion-synthesized materials of the same compositions. The findings reveal the successful synthesis of 12-18 nm bimetallic Cu-Ni nanoparticles with high phase homogeneity, alongside phase-segregated nanoparticles predicted by molecular dynamics simulations. Based on the comparison of the experimental and computational data, a possible scenario for phase segregation during the synthesis was proposed. It includes clustering of the atoms of the same type in an initial solution or the stage of gel formation and further developing segregation during the combustion/cooling stage. The research concludes that early synthesis stages, including particle preformation, significantly influence the phase homogeneity of multiprincipal element alloys. This study contributes to understanding nanomaterial formation, offering insights for improved alloy synthesis and enhanced functionalities in advanced applications.

Solar Assisted Mitigation of Chloramphenicol and H2 Evolution Using CuNi Alloy Nanoparticles on h-BN Doped g-C3N4: A Comprehensive Approach Combining Synchrotron and DFT Analysis.

A simple one-step deposition-precipitation method was used to synthesize highly active and well-defined CuNi alloy bimetallic nanoparticles supported on h-BN/g-C3N4. The nanocomposite was applied for hydrogen gas evolution via seawater splitting and photocatalytic chloramphenicol (CHP) removal. Through TEM and synchrotron studies, the formation of CuNi alloy and uniform distribution of CuNi bimetallic nanoparticles on the h-BN/g-C3N4 surface was observed. The EXAFS analysis verified the successful formation of the alloy, while the XPS and XANES spectra showed that the bimetallic nanoparticles are in a metallic state. Additionally, XANES revealed nanoparticle distortion upon interaction with the support, confirming the effective formation of the nanocomposite. The nanocomposite achieved a maximum hydrogen evolution rate of 3658.9 μmol g-1 h-1 for 5 wt % CuNi(3:1)/h-BN/g-C3N4, outperforming CuNi(3:1) nanoparticles and pristine g-C3N4 by 1.82 and 4.31 times, respectively. Additionally, it degraded chloramphenicol with a rate constant (kapp) of 0.018 min-1. Optical and electrochemical analysis revealed enhanced charge mobility, extended lifetime, improved photostability, and superior photoresponse. X-ray absorption spectroscopy (XAS) and density functional theory (DFT) calculations attributed the performance to the synergy between the bimetallic nanoparticles and the h-BN/g-C3N4 sheet. DFT calculations demonstrated the effective breakdown of chloramphenicol and the promotion of hydrogen gas evolution, aligning with experimental observations. Cytotoxicity of CHP post-treatment was analyzed using Drosophila melanogaster (fruit fly) and the Oregon-R strain of D. melanogaster.

Tribological behavior and lubrication mechanism of polyalphaolefin with added Cu-Ni bimetallic nanoparticles on a TiN coating

In this study, the tribological behavior of TiN coatings lubricated with a polyalphaolefin (PAO)-based oil containing Cu-Ni bimetallic nanoparticles was investigated under a maximum contact pressure of 0.9 GPa in reciprocating ball-on-disk mode. The addition of 0.1 wt% Cu-Ni nanoparticles to PAO6 reduced the friction coefficient to 0.018 and also decreased the wear rate of TiN coatings to 4.23 × 10-7 mm3/Nm. X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy revealed the deposition of Cu-Ni nanoparticles and carbon-based tribofilms on the contact region of the tribopairs. These originated from the tribo-induced degradation of the polyalphaolefin molecule in PAO6 + 0.1 %Cu-Ni nanoparticles, which helped decrease the COF and wear. Moreover, a comparative analysis suggested that the presence of nickel in the Cu-Ni nanoparticles had a catalytic effect during sliding. They facilitated the in situ formation of carbon-based film due to the degradation of polyalphaolefins under the combined effects of frictional heat and contact stress, demonstrating a self-repair capability.

Facile synthesis of Cu-Ni bimetallic nanoparticles using peppermint leaf extract for enhanced antimicrobial efficacy and solar-driven photocatalytic activity

Facile synthesis of Cu-Ni bimetallic nanoparticles using peppermint leaf extract for enhanced antimicrobial efficacy and solar-driven photocatalytic activity

Cu-Ni bimetallic nanoparticles anchored on halloysite nanotubes for the environmental remediation

Hereby, we report the synthesis of CuNi bimetallic nanoparticles (NPs)-decorated halloysite nanotubes (CuNi/HNTs) for the catalytic reduction of 4-nitroaniline (4-NA) and rhodamine B (RhB) dye in an aqueous medium at room temperature. In this work, CuNi/HNTs composites with different wt% of CuNi NPs were synthesized and characterized by various techniques such as SEM, EDS, XRD, TEM and XPS. The TEM characterization confirmed that the CuNi bimetallic NPs (∼ 11 nm) were successfully anchored onto the outer surface of HNTs. Among the prepared catalysts, Cu0.75Ni0.25/HNTs catalyst displayed highest catalytic activity in the reduction of 4-NA to its corresponding amino derivative in the presence of NaBH4 with a maximum conversion efficiency of >99% and an apparent rate constant kapp of 0.152 s−1 within 30 s of reaction time. Notably, even after 15 cycles of catalytic reduction of 4-NA and RhB, there was no apparent deactivation of the catalytic activity of the Cu0.75Ni0.25/HNTs catalyst, demonstrating the excellent catalytic reusability and stability. The presence of CuNi NPs with low Ni content enhanced the catalytic activity due to the synergetic effect. Moreover, the continuous flow fixed bed reactor designed with Cu0.75Ni0.25/HNTs catalyst exhibited the potential application for the reduction of 4-NA and RhB dye under mild reaction conditions. Furthermore, the present catalytic system could be applicable for the treatment of various wastewater effluents.

Antioxidant, photo-catalytic activities of biogenic Cu-Ni nano-composite using Terminalia chebula extract

Copper-nickel (Cu-Ni) Bimetallic nanoparticless have been synthesized in an eco-friendly manner using an aqueous extract of the polyphenol-rich Terminalia chebula fruit. The UV–Visible spectral analysis showed that a characteristic peak at λ max 530 nm which confirms the formation of Copper-Nickel (Cu-Ni) Bimetallic nanoparticles and that it was monodisperse. The FTIR and EDX studies revealed that polyphenols in the aqueous extract of Terminalia chebula were utilized for producing the Cu-Ni Bimetallic nanoparticles. The XRD studies confirmed the resultant Copper-Nickel (Cu-Ni) compound was FCC. The sphere shape was confirmed by TEM analysis, with an average size of 20.6 nm. The objective of this study was to evaluate the photocatalytic and antioxidant properties of the biosynthesized Copper-Nickel (Cu-Ni) Bimetallic nanoparticles. Both Congo red dye and Eosin-Y are known to cause cancer. They were broken down by a catalyst in 30 and 60 min, respectively, and their degradation was found to follow first-order dynamics. Maximum antioxidant activity against DPPH was observed at 150 µg/ml, with an EC50 of 78.51 and an EC90 of 65.01 µg/ml.

CuNi Nanoalloys with Tunable Composition and Oxygen Defects for the Enhancement of the Oxygen Evolution Reaction**

AbstractColloidal synthesis is an excellent tool for the study of cooperative effects in nanoalloys. In this work, bimetallic CuNi nanoparticles of defined size and composition are fully characterized and tested for the oxygen evolution reaction. Copper addition to nickel leads to modifications in the structural and electronic properties, showing a higher concentration of surface oxygen defects and formation of active Ni3+ sites under reaction conditions. The ratio OV/OL between oxygen vacancies and lattice oxygen shows a clear correlation with the overpotential, being an excellent descriptor of the electrocatalytic activity. This is attributed to modifications in the crystalline structure, leading to lattice strain and grain size effects. Bimetallic Cu50Ni50NP showed the lowest overpotential (318 mV vs RHE), low Tafel slope (63.9 mV dec−1), and excellent stability. This work unravels the relative concentration between oxygen defects and lattice oxygen (OV/OL) as an excellent descriptor of the catalytic activity of bimetallic precatalysts.

CuNi Nanoalloys with Tunable Composition and Oxygen Defects for the Enhancement of the Oxygen Evolution Reaction.

Colloidal synthesis is an excellent tool for the study of cooperative effects in nanoalloys. In this work, bimetallic model CuNi nanoparticles of defined size and composition are fully characterized and tested for the oxygen evolution reaction. Copper addition to nickel leads to modifications in the structural and electronic properties, showing a higher concentration of surface oxygen defects and formation of active Ni3+ sites under reaction conditions. The ratio OV/OL between oxygen vacancies and lattice oxygen shows a clear correlation with the overpotential, being an excellent descriptor of the electrocatalytic activity. This is attributed to modifications in the crystalline structure, leading to lattice strain and grain size effects. Bimetallic Cu50Ni50NP showed the lowest overpotential (318 mV vs RHE), low Tafel slope (63.9 mV dec-1), and excellent stability. This work unravels the relative concentration between oxygen defects and lattice oxygen (OV/OL) as an excellent descriptor of the catalytic activity of bimetallic precatalysts.

Enhanced catalytic performance of CuNi bimetallic nanoparticles for hydrogen evolution from ammonia borane hydrolysis

Ammonia borane (AB, NH3BH3) hydrolysis is an effective way to safely generate hydrogen. However, a suitable catalyst is indispensable because the hydrolytic reaction cannot take place kinetically at room temperature. In this work, CuNi alloy nanoparticles are immobilized on porous graphitic carbon nitride (g-C3N4) with a facile adsorption-chemical reduction method. Benefiting from the hierarchical porous structure of the support, the interesting alloy effect of Cu and Ni, as well as the synergistic effect between g-C3N4 and the CuNi alloys, the optimal Cu0·7Ni0.3/g-C3N4 catalyst displays excellent catalytic performance in AB hydrolysis, such as high turnover frequency (2.08 min−1, at 303 K), low apparent activation energy (23.58 kJ mol−1), and satisfactory durability. The results verify that the optimal catalyst has particular potential in hydrogen energy utilization due to the advantages such as the facile preparation procedure, low cost and excellent catalytic behavior.

Nanoarchitectonics of CuNi bimetallic nanoparticles in ionic liquids for LED-assisted synergistic CO2 photoreduction

An efficient and robust photocatalysts have been developed by combining bimetallic CuNi nanoparticles and TiO2. Simple co-reduction of CuCl2.2H2O and NiCl2.6H2O in 1-n-butyl-methylimidazolium tetrafluoroborate (BMIm.BF4) ionic liquid affords small sized (4–5 nm) bimetallic CuNi NPs. Low-Energy Ion Scattering (LEIS) and magnetic measurements analyses reveals that the NPs are alloyed nanostructure-having Ni enriched surface. CuNi NPs decorated on P25-TiO2 remarkably promote the generation of CH3OH and syngas as compared to their monometallic counter-parts using 1200 mW LEDs of 450 nm (visible) light irradiations in an optofluidic microreactor. The system continuously produces CH3OH with a rate of 102.1 μm.g−1.h−1 (AQY 0.90%) and syngas (H2 118.8 and CO 24.6 μmol.g−1.h−1), represents a high yield and quantum efficiency. Where as, its counter-part, Ni/TiO2, generate CH3OH with a rate of 37.0 μm.g−1.h−1, H2 200.0 μmol.g−1.h−1 and CO 15.1 μmol.g−1.h−1 having 0.33, 0.59 and 0.1% AQY, respectively. The presence of Cu in CuNi NPs significantly boosts the catalytic performance via metal dilution and synergistic effect, causes the red shift and increases the conductivity, while Ni increases the band gap, thereby achieving a record high CH3OH rate generation.

Hydrodeoxygenation of p-cresol over CuNi@C catalyst derived from metal-organic frameworks precursor

Catalytic hydrodeoxygenation is becoming more important industrially due to the urgent need for the conversion of oxygen-rich biomass into a renewable hydrocarbon energy source as means to tackle the climate change crisis. This research examined the catalytic hydrogenation of p-cresol as a model compound, using CuNi bimetallic nanoparticles incorporated into a carbon matrix (CuNi@C) as the catalysts, which were prepared using MOFs as the precursors. Various MOFs with varying molar content of nickel (Cu, CuNi0.2, CuNi0.5, CuNi0.8 and CuNi1.1) were prepared and used to derive the MOF-based bimetallic catalysts. The effect of the relative bimetallic compositions, surface morphology, and the oxidation of the metals of the catalysts was studied at different hydrogenation reaction temperatures varying from 200 to 300 °C. Advanced characterisations demonstrate that the MOF-derived Cu/Ni carbon nanocomposite catalyst at a Cu/Ni mole ratio of 0.5 (CuNi0.5/C) shows the highest catalytic activities at 300 °C, giving rise to a conversion rate of 80.3% and selectivity of 82.7% for the formation of 4-methylcyclohexanol (hydrogenation pathway). Cyclic hydrogenation tests also reveal that the CuNi0.5/C showed the highest thermochemical stability with a negligible decrease in catalytic activity despite the high temperature examined for a fast conversion. The preliminary results augur well for the sound promise of using corresponding MOFs derived novel catalysts for hydrogenation application.

Noble-metal-free CuNi/Co3O4 hybrid nanosheets as efficient and magnetically recyclable catalysts for hydrolysis of ammonia borane

The development of inexpensive and high-performance catalysts is a hot topic in the field of catalytic hydrolysis of ammonia borane (AB). In this work, a series of CuNi bimetallic nanoparticles (NPs) anchored on Co3O4 with magnetic properties was fabricated via impregnation reduction method. Befitting from the synergistic effect between Cu and Ni species and the strong interactions between the bimetallic NPs and the supporting substrate, the as-prepared CuNi/Co3O4 catalyst (with a bimetallic loading weight of 6.2 wt% and the mole ratio of Cu:Ni is 1:1) affords a high hydrogen generation rate of 11,846.9 mL min−1 g−1 with a total turnover frequency (TOF) value of 31.5 molH2 molmetal−1 min−1 0.14 M NaOH medium at 298 K. Besides, this catalyst also exhibits good magnetic separability. These results indicate that cobalt oxide has good application prospects in the field of AB hydrolysis, which may provide a promising lead for the construction of other efficient heterogeneous catalysts for industrial applications in energy and environmental fields.

Efficient photothermal-assisted photocatalytic hydrogen production over a plasmonic CuNi bimetal cocatalyst

It is challenging to maximize the utilization of solar energy using photocatalysis or photothermal catalysis alone. Herein, we report a full spectrum solar energy driven photothermal-assisted photocatalytic hydrogen production over CuNi bimetallic nanoparticles co-loaded with graphitized carbon nitride nanosheet layers (CuxNiy/CN) which are prepared by a facile in-situ reduction method. Cu5Ni5/CN shows a high hydrogen production rate of 267.8 μmol g−1 h−1 at room temperature, which is 70.5 and 1.34 times of that for pure CN (3.8 μmol g−1 h−1) and 0.5 wt% Pt/CN (216 μmol g−1 h−1), respectively. The photothermal catalytic hydrogen activity can be further increased by 3.7 times when reaction solution is external heated to 100 °C. For the photothermal catalytic system, the local surface plasmon resonance (LSPR) effect over active Cu nanoparticles can absorb near-infrared light to generate hot electrons, which are partially quenched to generate heat for heating of the reaction system and partially transported to the active sites, where the Ni nanoparticles as another functional component couple the electrons and heat to finally promote the photothermal catalytic activity. Our result suggests that a rational design of the catalyst with bifunctional atomic components can photothermocatalysis-assisted photocatalysis to maximize utilization solar energy for efficient full spectrum conversion.

Led-Assisted Synergistic Co2 Photoreduction Via Cuni Bimetallic Nanoparticles Prepared in Ionic Liquids

Led-Assisted Synergistic Co2 Photoreduction Via Cuni Bimetallic Nanoparticles Prepared in Ionic Liquids

Sea-Island-Like Morphology of CuNi Bimetallic Nanoparticles Uniformly Anchored on Single Layer Graphene Oxide as a Highly Efficient and Noble-Metal-Free Catalyst for Cyanation of Aryl Halides

Aryl nitriles are versatile compounds that can be synthesized via transition-metal-mediated cyanation of aryl halides. Most of the supported-heterogeneous catalysts are noble-metals based and there are very limited numbers of efficient non-noble metal based catalysts demonstrated for the cyanation of aryl halides. Herein, bimetallic CuNi-oxide nanoparticles supported graphene oxide nanocatalyst (CuNi/GO-I and CuNi/GO-II) has been demonstrated as highly efficient system for the cyanation of aryl halides with K4[Fe(CN)6] as a cyanating agent. Metal-support interaction, defect ratio and synergistic effect with the bimetallic nanocatalyst were investigated. To our delight, the CuNi/GO-I system activity transformed a wide range of substrates such as aryl iodides, aryl bromides, aryl chlorides and heteroaryl compounds (Yields: 95–71%, TON/TOF: 50–38/2 h−1). Moreover, enhanced catalytic performance of CuNi/GO-I and CuNi/GO-II in reduction of 4-nitropehnol with NaBH4 was also confirmed (kapp = 18.2 × 10−3 s−1 with 0.1 mg of CuNi/GO-I). Possible mechanism has been proposed for the CuNi/GO-I catalyzed cyanation and reduction reactions. Reusability, heterogeneity and stability of the CuNi/GO-I are also found to be good.

Selective reduction of nitro group using CuNi bimetallic nanoparticles

Bimetallic nanoparticles have shown a lot of promise as catalysts in the recent years. This piece of work highlights the use of nanocatalyst for the chemoselective reduction of nitro group in presence of other reducible functional groups. CuNi bimetallic nanoparticles of varying composition (1:1, 1:2) have been synthesized by polyol method using metal sulphates with hydrazine hydrate as reducing agent. The characterization of synthesised nanoparticles was done by XRD and FESEM with EDX, which confirm FCC structure and composition of synthesised bimetallic nanoparticles. Particle size varies with composition i.e. 23 nm for (1:1) and 20 nm for (1:2). The selective reduction of p-nitrophenol, p-nitrobenzaldehyde and 2,4 dinitrophenol was performed in water using both single Ni nanoparticles and bimetallic CuNi nanoparticles (1:1, 1:2) with hydrazine hydrate as reducing agent at room temperature. The various amino products obtained has various industrial applications. UV–visible spectroscopy was used to monitor the progress of the reaction. The bimetallic nanoparticles facilitated the rate of reaction much as compared to single Ni nanoparticles.

Bimetallic Cu-Ni nanoparticles supported on activated carbon for catalytic oxidation of benzyl alcohol

A series of bimetallic copper-nickel (CuNix, x = 0.1, 0.2, 0.5 and 1) nanoparticles supported on activated carbon (AC) were prepared by deposition-precipitation method for the oxidation of benzyl alcohol to benzaldehyde using hydrogen peroxide as oxidising agent. Analyses by means of X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) confirmed that Cu and Ni was successfully added on the surface of activated carbon. CuNi1/AC showed the best catalytic activity for the oxidation of benzyl alcohols to the corresponding aldehyde within a short reaction period at 80 °C. The catalytic performance is significantly enhanced by the addition of equal amount of Ni as compared to the monometallic counterpart. This result indicates the synergistic effect between Ni and Cu particles in the catalytic oxidation reaction.

Low-cost CuNi@MIL-101 as an excellent catalyst toward cascade reaction: integration of ammonia borane dehydrogenation with nitroarene hydrogenation.

Bimetallic CuNi nanoparticles (NPs) with low cost were rationally confined inside MIL-101 to give CuNi@MIL-101, which exhibits high efficiency and excellent recyclability toward the hydrogenation of nitroarenes under mild conditions on coupling with ammonia borane dehydrogenation. This is the first report on MOF-stabilized base metal NPs for cascade reactions.

Highly efficient silica coated CuNi bimetallic nanocatalyst from reverse microemulsion

Silica protected CuNi bimetallic nanoparticles (CuNi@SiO2) were successfully prepared by a modified co-reduction method. Typically, ammoniacal Cu(II) and Ni(II) were firstly dispersed and encapsulated inside silica by the method of reverse microemulsion. Then, ultra small CuO and NiO particles were in-situ formed during calcination under air. CuNi bimetallic nanoparticles were obtained by the co-reduction of CuO and NiO under H2 at high temperature. The composition and size of CuNi bimetallic nanoparticles was tuned simply by varying the concentration of precursor solutions. The samples were characterized by FT-IR, TEM, XPS, XRD and ICP-OES. The reduction of p-nitrophenol by NaBH4 was chosen as model reaction to evaluate the catalytic activity. The results indicate that CuNi bimetallic nanoparticles prepared by our method show size and composition dependent catalytic activity. The activation energy of Cu54Ni46@SiO2 for the same reaction was calculated as to be 16.6kJ/mol which was much lower than that of Cu@SiO2 (29.0kJ/mol) and Ni@SiO2 (39.5kJ/mol).

Surface composition changes of CuNi-ZrO2 during methane decomposition: An operando NAP-XPS and density functional study

Bimetallic CuNi nanoparticles of various nominal compositions (1:3, 1:1, 3:1) supported on ZrO2 were employed for operando spectroscopy and theoretical studies of stable surface compositions under reaction conditions of catalytic methane decomposition up to 500°C. The addition of Cu was intended to increase the coke resistance of the catalyst. After synthesis and (in situ) reduction the CuNi nanoparticles were characterized by HR-TEM/EDX, XRD, FTIR (using CO as probe molecule) and NAP-XPS, all indicating a Cu rich surface, even when the overall nanoparticle composition was rich in Ni. Density functional (DF) theory modelling, applying a recently developed computational protocol based on the construction of topological energy expressions, confirmed that in any studied composition Cu segregation on surface positions is an energetically favourable process, with Cu preferentially occupying corner and edge sites. Ni is present on terraces only when not enough Cu atoms are available to occupy all surface sites.When the catalysts were applied for methane decomposition they were inactive at low temperature but became active above 425°C. Synchrotron-based operando NAP-XPS indicated segregation of Ni on the nanoparticle surface when reactivity set in for CuNi-ZrO2. Under these conditions C 1s core level spectra revealed the presence of various carbonaceous species at the surface. DF calculations indicated that both the increase in temperature and especially the adsorption of CHx groups (x=0-3) induce the segregation of Ni atoms on the surface, with CH3 providing the lowest and C the highest driving force.Combined operando and theoretical studies clearly indicate that, independent of the initial surface composition after synthesis and reduction, the CuNi-ZrO2 catalyst adopts a specific Ni rich surface under reaction conditions. Based on these findings we provide an explanation why Cu rich bimetallic systems show improved coke resistance.