CuFeS2 Nanoparticles Research Articles

Investigation of Thermophysical Properties of CuFeS2 Nanoparticles Prepared by Pulsed Laser Ablation Technique.

Investigation of Thermophysical Properties of CuFeS2 Nanoparticles Prepared by Pulsed Laser Ablation Technique.

Preparation and Characterization of CuFeS2 Nanoparticles Synthesized via Hydrothermal Method

Abstract: This research involved the successful synthesis of CuFeS2 nanoparticles using a hydrothermal method. The CuFeS2 nanoparticles were characterized using various analytical techniques, including X-ray diffraction (XRD), Raman spectroscopy, field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDX), UV-Visible spectroscopy, and Brunauer-Emmett-Teller (BET) surface area analysis. The tetragonal crystalline structure was determined using X-ray diffraction (XRD) examination, indicating a particle size of 14 nm. The existence of chalcopyrite CuFeS2 nanoparticles was established by the analysis of Raman spectra. The amorphous morphology was observed by FESEM imaging. The existence of Cu, Fe,and S elements was verified using EDX analysis, with no significant impurities observed. The UV-Visible investigation revealed a significant capacity for absorption within the wavelength region of 500-600 nm, accompanied by an energy band gap of 2.35 eV. The examination of BETsurface area revealed a surface area of 62 m²/g and a pore size of 10 nm. The obtained findings suggest that the CuFeS2 nanoparticles possess favorable properties that render them appropriate for use in photocatalytic applications.

Electron transfer and energy exchange between a covalent organic framework and CuFeS2 nanoparticles.

CuFeS2 is a prominent chalcogenide that possesses similar optical properties and a significantly lower cost, compared to gold. Additionally, covalent organic frameworks are a class of materials at the forefront of current research, mainly used as photoactive components and porous absorbers. Hence, in this work, hydrophilic CuFeS2 particles are coupled with multi-functional covalent organic frameworks through ionic bonding to produce a hybrid material with unique and optimized properties. To render the CuFeS2 particles negatively charged and dispersible in water, we coated them with sodium dodecyl sulfonate, shifting the surface plasmon resonance of the nanoparticles from 472 to 492 nm. When they are electrostatically assembled with the positively charged COFs, an S-scheme is formed and the fluorescence of the hybrid materials is highly quenched, with the electron transfer happening from the networks to the nanoparticles and a simultaneous energy exchange which is dependent on the emission wavelength. Through detailed fluorescence spectroscopy, time-resolved measurements and Stern-Volmer analysis, we identified an efficient emission quenching that differs from the bulk to the exfoliated hybrid system, while detailed electron microscopy studies demonstrated the strong interaction between the two components. The quenching mechanisms and the on or off surface resonance dependent lifetime could be applied to photocatalytic and photovoltaic applications.

Surface-engineered CuFeS2/Camptothecin nanoassembly with enhanced chemodynamic therapy via GSH depletion for synergistic photo/chemotherapy of cancer

Constructing the antitumor agents that are responsive to reactive oxygen species (ROS) have received considerable interest owing to their low drug resistance, high lethality of cytotoxic radicals such (•OH, •O2-, 1O2), and ease of combining with other therapeutic strategies. In this work, ROS-mediated therapies of quasi-spherical chalcogenide, CuFeS2 nanoparticles (NPs) were reported. Firstly, CuFeS2 NPs capped with oleylamine-capping agent were synthesized using the thermal decomposition technique, and surface modification was accomplished by micelles formation using an amphiphilic copolymer, pluronic 127 (PF127), to improve the water dispersibility of CuFeS2 NPs. The resulting material, CFS@PF nanoassembly, exhibited good dispersibility in an aqueous solution, which was attributed to the PF127 copolymer's hydrophilic property. Due to their strong absorption spectra in the near-infrared region (NIR), CFS@PF nanoassembly demonstrated remarkable photothermal conversion efficiency (PCE) of 63.3% upon NIR laser irradiation for photothermal therapy (PTT), which might induce hyperthermia in cancer treatment. Furthermore, CFS@PF nanoassembly could efficiently trigger not only singlet oxygen (1O2) under laser illumination for photodynamic therapy (PDT), but also cytotoxic hydroxyl radical (•OH) in the presence of peroxide solution (H2O2) for chemodynamic therapy (CDT) via Fenton reaction. Interestingly, the intracellular antioxidant, glutathione (GSH), could be effectively depleted via Cu–Fe-induced redox reaction, hence enhancing the efficacy of ROS-mediated therapeutics. In vitro experiments verified that CFS@PF NPs were more biocompatible with B16F1 and HeLa cells, but also exhibited substantial toxicity in the presence of laser and H2O2, resulting in 80% cell death through CDT/PDT/PTT synergistic effects. More crucially, CFS@PF micelles are employed in drug delivery for loading of Camptothecin (CPT), generating a CFS@PF/CPT nanoassembly for chemotherapy with a loading efficiency of 46.42%, and CPT release at various pH conditions was examined. The results of the cell experiments indicated that drug pairings boost tumor-killing performance by up to 90% due to the synergistic effect of CDT/PTT/chemotherapy. Overall, this study explored CFS@PF/CPT NPs, which might be potential anticancer agents for cancer therapy in the future of nanomedicine.

Photothermal Regulated Nanozyme of CuFeS2 Nanoparticles for Efficiently Promoting Wound Healing Infected by Multidrug Resistant Bacteria.

Peroxidase-mediated chemokinetic therapy (CDT) can effectively resist bacteria; however, factors such as the high dosage of drugs seriously limit the antibacterial effect. Herein, CuFeS2 nanoparticles (NPs) nanozyme antibacterial system with the photothermal effect and peroxidase-like catalytic activity are proposed as a combined antibacterial agent with biosafety, high-efficiency, and broad-spectrum antibacterial ability. In addition, the as-obtained CuFeS2 NPs with a low doses of Cu+ and Fe3+ can change the permeability of bacterial cell membranes and break the antioxidant balance by consuming intracellular glutathione (GSH), which results in more conducive ROS production. Meanwhile, the photothermal heating can regulate the CuFeS2 NPs close to their optimal reaction temperature (60 °C) to release more hydroxyl radical in low concentrations of H2O2 (100 µM). The proposed CuFeS2 NPs-based antibacterial system achieve more than 99% inactivation efficiency of methicillin-resistant Staphylococcus aureus (106 CFU mL−1 MRSA), hyperspectral bacteria β-Escherichia coli (106 CFU mL−1 ESBL) and Pseudomonas aeruginosa (106 CFU mL−1 PA), even at low concentration (2 μg mL−1), which is superior to those of the conventional CuO NPs at 4 mg mL−1 reported in the literature. In vivo experiments further confirm that CuFeS2 NPs can effectively treat wounds infected by MRSA and promote the wound healing. This study demonstrates that excellent antibacterial ability and good biocompatibility make CuFeS2 NPs a potential anti-infection nanozyme with broad application prospects.

GSH-responsive sequential mitochondria-targeting nanoagents for photothermal-enhanced chemodynamic therapy

Mitochondria-targeting nanoparticles have proven to be promising platforms for cancer therapy. However, precise mitochondria targeting in the complex tumor environment is still challenging and requires more ingenious design. Herein, we developed the glutathione (GSH)-responsive nanoagents to target mitochondria in tumor cells precisely for photothermal-enhanced chemodynamic therapy (CDT). The nanoagents were designed by preparing the cubic shape of CuFeS2 nanoparticles that sequentially modified with mitochondrial-targeting peptide (KLAK) and integrin-targeting peptide (RGD), which KLAK and RGD were covalently conjugated via a disulfide bond. After being endocytosed into integrin-overexpressed tumor cells, disulfide bond was broken and RGD was separated from the nanoagents in the presence of overexpressed GSH. Then, the exposure of KLAK on the surface further aid the rustling nanoagents to target mitochondria. Under NIR laser irradiation, the surrounding temperature of the nanoagents would rise due to their excellent photothermal effect, resulting in the improvement of the Fenton reaction from the CuFeS2. It was well demonstrated that this photothermal-enhanced chemodynamic therapy nanoplatform could effectively damage the mitochondrial function and further induce the apoptosis of tumor cells. As a therapeutic platform with both tumor/mitochondria-targeting and PTT-enhanced CDT, our study has provided a new path in the field of cancer therapy.

Explanation of the Opposing Shifts in the Absorption Edge and the Optical Resonance in CuFeS2 Nanoparticles

Size-dependent change of the electronic band structure is one of the key features of nanoparticles in the quantum confinement region. CuFeS2 nanoparticles have a strong absorption feature in the visible region that has, controversially, been described as neither an excitonic transition nor a free carrier plasmon oscillation. Instead, the absorption feature in CuFeS2 nanoparticles has been attributed to quasi-static optical resonances from inter-band transitions between the valence band (VB), intermediate band (IB), and conduction band (CB). As such, we hypothesized that the feature should be subject to quantum confinement effects through modification of the electronic bands. In this paper, we show experimentally that the optical resonance absorption peak red-shifts and the optical band gap blue-shifts as the particle size decreases. Through density functional theory (DFT) and the tight binding (TB) modeling, we elucidate the size dependence of the band structure, especially focusing on the change in the IB. Using a Lorentzian oscillator optical model to simulate the absorption spectrum with inputs from the DFT-calculated band structure and band shifts from the TB model, we find that the size-dependent shifts of the optical resonance peak position in CuFeS2 are due to a tri-band quantum confinement effect that results in both the VB to IB and IB to CB gap expansion that accompanies a decrease in particle size. We also find that the transitions between the IB and CB play only a minor role in the optical spectrum. Moreover, the linear optical Lorentzian model predicts that the optical resonance peak is tunable across the visible range by partially filling the IB, lowering the CB, or expanding the IB.

Green synthesis of CuFeS2 nanoparticles using mimosa leaves extract for photocatalysis and supercapacitor applications

We successfully synthesized CuFeS2 nanoparticles (NPs) using a simple synthesis method mediated by touch me not (Mimosa pudica) leaves extract. X-ray diffraction (XRD) was used to analyze the structural properties, and it shows that the CuFeS2 NPs have a tetragonal structure and quasi-pyramidal NPs of an average crystallite size of 31.0 nm with a secondary phase of few minor peaks of covellite (CuS). The optical characterization showed that CuFeS2 NPs have band gap energy ranges of 1.98–2.46 eV for different annealing temperatures. The electrochemical properties of the CuFeS2 NPs were investigated using cyclic voltammetry (CV), galvanostatic charge discharge (GCD), and electrochemical impedance spectroscopy (EIS). An appreciable value of specific capacitance of 501.4 F/g was obtained at a scan rate of 10 mV/s for the CuFeS2 NPs annealed at 250 °C which can be said to be within the optimum ideal annealing temperature for CuFeS2 NPs. The CuFeS2 NPs was used in the photodegradation of methylene blue (MB) under of solar irradiation. The highest rate constant of 3.1 × 10−2 min−1 and degradation efficiency of 98% were obtained for the unannealed CuFeS2 NPs with good stability after three cycles. Therefore, the synthesized CuFeS2 NPs were obtained using a Mimosa pudica leaves extract prospective application in both electrochemical energy storage devices and treatment of water contaminants. GO was added to increase the active sites for these ions, surface area, and conductivity of these electrodes for enhanced supercapacitive performance.

CuFeS2 Nanoassemblies With Intense Near-Infrared Absorbance for Photothermal Therapy of Tumors

Photothermal therapy is an efficient cancer treatment method. The development of nanoagents with high biocompatibility and near-infrared (NIR) photoabsorption band is a prerequisite to the success of this method. However, the therapeutic efficiency of photothermal therapy is rather limited because most of the nanoagents have a low photothermal conversion efficiency. In this study, we aimed to develop CuFeS2 nanoassemblies with an excellent photothermal effect using the liquid-solid-solution method. The CuFeS2 nanoassemblies we developed are composed of ultrasmall CuFeS2 nanoparticles with an average size of 5 nm, which have strong NIR photoabsorption. Under NIR laser illumination at 808 nm at the output power intensity of 1.0 W cm-2, the CuFeS2 nanoassemblies could rapidly convert NIR light into heat, achieving a high photothermal conversion efficiency of 46.8%. When K7M2 cells were incubated with the CuFeS2 nanoassemblies and then exposed to irradiation, their viability decreased progressively as the concentration of the CuFeS2 nanoassemblies increased. Furthermore, a concentration of 40 ppm of CuFeS2 nanoassemblies was lethal to the cells. Importantly, after intratumoral injection of 40 ppm CuFeS2 nanoassemblies, the tumor showed a high contrast in the thermal image after laser irradiation, and tumor cells with condensed nuclei and a loss of cell morphology could be thermally ablated. Therefore, the CuFeS2 nanoassemblies we synthesized have a high biocompatibility and robust photothermal effect and can, thus, be utilized as a novel and efficient photothermal agent for tumor therapy.

Mechanochemical synthesis, structural, magnetic, optical and electrooptical properties of CuFeS2 nanoparticles

The rapid mechanochemical synthesis of nanocrystalline CuFeS2 particles prepared by high-energy milling for 60 min in a planetary mill from copper, iron and sulphur elements is reported. The CuFeS2 nanoparticles crystallize in tetragonal structure with mean crystallite size of about 38 ± 1 nm determined by XRD analysis. HRTEM study also revealed the presence of nanocrystals with the size of 5–30 nm with the tendency to form agglomerates. The Raman spectrum confirms the chalcopyrite structure. Low temperature magnetic data for CuFeS2 support the coexistence of antiferromagnetic and paramagnetic spin structure. Moreover, the hysteresis loops taken at temperatures from 5 K to 300 K revealed a presence of very small amount of ferromagnetic phase, which seems to be associated with the non-consumed elemental Fe in as-prepared nanoparticles. The optical band gap of CuFeS2 nanoparticles has been detected to be 1.05 eV, larger than band gap of the bulk material. The wider gap possibly resulted from the nano-size effect. Photoresponses of CuFeS2 nanoparticles were confirmed by I-V measurements under dark and light illumination. It was demonstrated that mechanochemical synthesis can be successfully employed in the one step preparation of nanocrystalline CuFeS2 with good structural, magnetic, optical and electrooptical properties.

Synthesis of CuFeS2 Nanoparticles by One-pot Facile Method

Monodisperse copper-iron-sulfide (CuFeS2) nanoparticles as the infrared light absorbing material (chalcopyrite, 0.65 eV), were synthesized based on facile, one step heating up method, by dissolving of CuCl, FeCl3 and SC(NH2)2 as precursors in oleylamine (OLA) alone or in combination with oleic acid (OA) and 1-octadecene (ODE) as solvent. The phase, size, morphology, and size distribution were controlled by the reaction conditions and temperature. The CuFeS2 nanoparticles were characterized by transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, Raman spectrum and ultraviolet-visible-near infrared. The three main absorbance region was observed in the ultraviolet, visible and infrared as a hybridization of Fe 3d-S 3p among the valence band (Cu 3d-S 3p) and conduction band (Cu 4s-Fe 4s). Well controlled CuFeS2 triangular pyramidal along with semi-hexagonal and hexagonal shape (~ 20-25 nm) was obtained by using OLA or a mixture of OLA along with OA and ODE, respectively, with 210 °C heating up and 4 h annealing time.

PVP-assisted synthesis of shape-controlled CuFeS2 nanocrystals for Li-ion batteries

In this paper, chalcopyrite CuFeS2 with sheet-like or rod-like morphology has been synthesized by solvothermal reaction route in the presence of poly(vinylpyrrolidone) (PVP). The concentration of PVP has significant influences on the morphology of CuFeS2 nanocrystals. With the increasing concentrations of PVP, the sheet morphology of CuFeS2 becomes more uniform. Meanwhile, the average dimensions of CuFeS2 sheets are reduced and small CuFeS2 nanoparticles are clearly decreased. When the molar ratio of CuFeS2 to PVP is 1:2, the shape of CuFeS2 changes to rod-like, which is composed of CuFeS2 sheets. Considering the influence of uniformity and shape of CuFeS2 nanocrystals, the CuFeS2 nanocrystals with different molar ratios of PVP have been used as active component to prepare anode for Li-ion batteries. The Li-ion battery using CuFeS2 nanocrystals with the molar ratio of 1:2 to PVP shows the highest reversible specific capacity of ~519 mAh/g after 50 cycles at a current density of 100 mA/g and maintains a specific capacity of ~400 mAh/g at a density of 1000 mA/g. The results demonstrate that the PVP-assisted CuFeS2 electrodes are promising candidates for use as Li-ion batteries.

Synthesis, structural and magnetic properties of self-organized single-crystalline nanobricks of chalcopyrite CuFeS2

A thermal pyrolysis method has been developed to synthesize the tetragonal phase of chalcopyrite magnetic semiconductor CuFeS2 nanoparticles. All nanoparticles have the same anisotropic brick-like shape, and the “bricks” are self-organized in a certain orientation, creating well-ordered nanocomposites. High-resolution transmission electron microscopy and electron diffraction data show that every nanobrick is a single crystal with a layered atomic structure and characteristic dimensions of about 5nm×20nm in plane. Magnetic measurements support the antiferromagnetic spin structure and reveal the appearance of a small ferromagnetic component below 60K. Magnetic anomalies observed in the zero-field cooled magnetization curves at low temperatures may be related to an appearance of magnetic moment at the Cu ion site. The Mössbauer spectra show that only about 50% of Fe atoms are in the magnetically ordered α-phase of chalcopyrite. The remaining Fe is non-magnetic and may be located either in the γ-phase of chalcopyrite or in isocubanite.

Cyclic microwave-assisted synthesis of CuFeS2 nanoparticles using biomolecules as sources of sulfur and complexing agent

Copper iron sulfide (CuFeS2) nanoparticles were successfully synthesized by a 300W cyclic microwave radiation, exposing onto ethylene glycol containing Cu(CH3COO)2, FeCl3·6H2O or FeCl2·4H2O and l-cysteine biomolecules. X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), Raman spectrometry and X-ray photoelectron spectroscopy (XPS) revealed the presence of pure tetragonal chalcopyrite CuFeS2 nanoparticles with valence states of Cu+, Fe3+ and S2− and four Raman shifts at 215.0–218.6, 280.2–281.4, 394.4–394.9 and 472.2–473.4cm−1. A formation mechanism of the products was also proposed according to the experimental results.

Hydrothermal synthesis of chalcopyrite using an environmental friendly chelating agent

An environmental friendly route to fabricate CuFeS2 nanoparticles is presented. In this study, the CuFeS2 nanoparticles were synthesized using a hydrothermal chelation method at relatively low temperature and without introducing organic solvents. The citric acid was added as a chelating agent, which may decrease the impurity phase. The synthesized CuFeS2 nanoparticles were characterized by XRD, SEM, TEM, FTIR and UV–vis. The characterization results showed that the citric acid could form chelating complexes with iron and copper and promote the hydrothermal reaction. The synthesized CuFeS2 nanoparticles have cuboidal crystal forms with particle sizes between 100 and 200nm. The energy gap was measured to be 0.53eV.

A convenient synthesis of nanocrystalline chalcopyrite, CuFeS2 using single‐source precursors

AbstractNanocrystalline chalcopyrite (CuFeS2) have been synthesized using single‐source precursors, CuL2 and Cu(LH)2Cl2 (where LH = monoacetylferrocene thiosemicarbazone) by pyrolysis and solvothermal decomposition methods. The nanocrystals were characterized by UV–visible spectroscopy, X‐ray powder diffraction, transmission electron microscopy and energy dispersive X‐ray analysis. The magnetic character was determined by the hysteresis loop. CuFeS2 nanocrystallites prepared by the pyrolysis of CuL2 and Cu(LH)2Cl2 have a cubic phase and rod‐like morphology with diameters of about 18 and 15 nm, respectively, and lengths of about 195–390 and 100–145 nm, respectively. However, CuFeS2 nanoparticles obtained by solvothermal route from CuL2 and Cu(LH)2Cl2, which are capped with ethylene glycol, possess a nearly spherical shape with an average grain size of 16 and 11 nm, respectively. Copyright © 2009 John Wiley & Sons, Ltd.