Ultrafine Nanoparticle‐Supported Ru Nanoclusters with Ultrahigh Catalytic Activity

The design of an ideal heterogeneous catalyst for hydrogenation reaction is to impart the catalyst with synergetic surface sites active cooperatively toward different reaction species. Herein a new strategy is presented for the creation of such a catalyst with dual active sites by decorating metal and metal oxide nanoparticles with ultrafine nanoclusters at atomic level. This strategy is exemplified by the design and synthesis of Ru nanoclusters supported on Ni/NiO nanoparticles. This Ru‐nanocluster/Ni/NiO‐nanoparticle catalyst is shown to exhibit ultrahigh catalytic activity for benzene hydrogenation reaction, which is 55 times higher than Ru–Ni alloy or Ru on Ni catalysts. The nanoclusters‐on‐nanoparticles are characterized by high‐resolution transmission electron microscope, Cs‐corrected high angle annular dark field‐scanning transmission electron microscopy, elemental mapping, high‐sensitivity low‐energy ion scattering, and X‐ray absorption spectra. The atomic‐scale nanocluster–nanoparticle structural characteristics constitute the basis for creating the catalytic synergy of the surface sites, where Ru provides hydrogen adsorption and dissociation site, Ni acts as a “bridge” for transferring H species to benzene adsorbed and activated at NiO site, which has significant implications to multifunctional nanocatalysts design for wide ranges of catalytic reactions.     

Superior bactericidal activity of SDS capped silver nanoparticles: Synthesis and characterization

Silver nanoparticles were synthesized through UV photo-reduction of silver nitrate aqueous solution, containing ethanol and sodium dodecyl sulfate (SDS) using an UV digester equipped with high pressure mercury lamp of 500 W. The synthesized nanoparticles were characterized by UV–vis spectroscopy (UV–vis), transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The formation of silver nanoparticles was confirmed from the appearance of surface plasmon absorption maxima at 418 nm. TEM showed the spherical nanoparticles with size in 23–67 nm (average 45 ± 10 nm). The silver nanoparticles were stable for more than 8 months. The antibacterial activity of these SDS capped silver nanoparticles was tested using Pseudomonas aeruginosa as a model strain for gram-negative bacteria. SDS capped silver nanoparticles exhibit a much higher bactericidal activity compared to silver nanoparticles capped with other capping agents. Even at a low silver nanoparticle concentration of 5 μg/ml, complete inhibition of 10⁷ colony forming units (CFU) was achieved with SDS capped silver nanoparticles. This concentration is much lower than the values reported by other authors. This enhanced bactericidal activity is attributed to much efficient transport of silver nanoparticles by SDS to the outer membrane of cell wall compared to the other capping agents and have a better interaction of nanoparticles with the cell.     

In vitro cytotoxicity of surface modified bismuth nanoparticles

This paper describes in vitro cytotoxicity of bismuth nanoparticles revealed by three complementary assays (MTT, G6PD, and calcein AM/EthD-1). The results show that bismuth nanoparticles are more toxic than most previously reported bismuth compounds. Concentration dependent cytotoxicities have been observed for bismuth nanoparticles and surface modified bismuth nanoparticles. The bismuth nanoparticles are non-toxic at concentration of 0.5 nM. Nanoparticles at high concentration (50 nM) kill 45, 52, 41, 34 % HeLa cells for bare nanoparticles, amine terminated bismuth nanoparticles, silica coated bismuth nanoparticles, and polyethylene glycol (PEG) modified bismuth nanoparticles, respectively; which indicates cytotoxicity in terms of cell viability is in the descending order of amine terminated bismuth nanoparticles, bare bismuth nanoparticles, silica coated bismuth nanoparticles, and PEG modified bismuth nanoparticles. HeLa cells are more susceptible to toxicity from bismuth nanoparticles than MG-63 cells. The simultaneous use of three toxicity assays provides information on how nanoparticles interact with cells. Silica coated bismuth nanoparticles can damage cellular membrane yet keep mitochondria less influenced; while amine terminated bismuth nanoparticles can affect the metabolic functions of cells. The findings have important implications for caution of nanoparticle exposure and evaluating toxicity of bismuth nanoparticles.     

A photochemical method for controlling the size of CdS nanoparticles

The optical and electrical properties of semiconductor nanoparticles are strongly dependent on their size. A flexible control of the size of the nanoparticles is of interest for tuning their properties for different applications. Here we use a coupled method to control the size of CdS nanoparticles. The method involves the photochemical growth of CdS nanoparticles together with the use of a capping agent as an inhibiting factor. CdS nanoparticles were formed through a photoinduced reaction of CdSO(4) and Na(2)S(2)O(3) in an aqueous solution. Mercaptoethanol (C(2)H(6)OS) was used as the capping agent, and we investigated the effect of illumination time, illumination intensity and the concentration of capping agent on the nanoparticle size. Transmission electron microscopy (TEM) shows crystalline nanoparticles with relatively low dispersion. Optical absorption spectroscopy was mainly used to measure the band gap and size of the nanoparticles. Increasing the illumination time or illumination intensity increases the nanoparticle size, while higher capping agent concentration leads to smaller nanoparticle size. A band gap range of 2.75-3.4?eV was possible with our experimental conditions, corresponding to a 3.2-6.0?nm size range.     

Size control and magnetic properties of single layer monodisperse Ni nanoparticles prepared by magnetron sputtering

Single layer monodisperse Ni nanoparticles were successfully prepared by reductive annealing of NiO films formed by magnetron sputtering. The spherical Ni nanoparticles had a monodisperse distribution on the substrate. The formation process of Ni nanoparticles was investigated, and the Ni nanoparticle size can be precisely controlled by the magnetron sputtering time. Morphology of these nanoparticles was observed with scanning electron microscopes and transmission electron microscopes. Magnetic properties of Ni nanoparticles have been confirmed by using a vibration sample magnetometer. The blocking temperature, particle size, and effective anisotropy constant were calculated by fitting the relationship between coercivity and temperature.     

Screening of metal-resistant coal mine bacteria for biofabrication of elemental silver nanoparticle

Green synthesis approaches for nanoparticle synthesis are considered as nontoxic, eco-friendly and cost-effective approaches than other physical and chemical approaches. Here, we report green synthesis of silver nanoparticle using the bacteria from the habitat of relatively metal-rich coal mine dust. The bacteria showed resistance to significant concentration of anti-microbial Ag(I) ion. The nanoparticle was synthesized at minimum inhibitory concentration (MIC) of Ag(I) using only two isolates. The synthesis of silver nanoparticle was confirmed from the surface plasmon resonance property of the nanoparticle, whereas morphological features were studied using field emission scanning electron microscope. The hydrodynamic size analysis showed the presence of microparticles along with the nanoparticles. Additionally, IR study provided information about the bacterial proteins involved in either reduction of Ag(I) into silver nanoparticle or capping of reduced silver nanocrystal or both. Thus, majority of the bacteria found in the coal mines have the resistance against the antimicrobial metal ion, and the potential to reduce the ion into nano- or micro-particles. Hence, the bacteria can be used as a single cell factory for production of silver nanomaterial.     

Facile microwave‐assisted synthesis of NiO nanoparticles and its effect on soybean (Glycine max)

NiO nanoparticles in high purity, 15 ± 0.5 nm in size, were prepared via solid‐state microwave irradiation. The [Ni(NH₃)₆](NO₃)₂ complex as a novel source was decomposed in the presence of microwave irradiation for a short time (10 min). The present method is facile, safe, and low‐cost. This method exhibits other advantages; there is no need of a solvent, fuel, surfactant, expensive material, or complex instrument. Synthesised NiO nanoparticles were determined by various analyses. Also, for the first time, NiO nanoparticle effects on biochemical factors in soybean were investigated. Seeds of soybean were grown in the Murashige and Skoog agar medium containing different concentrations of NiO nanoparticles (0, 200, and 400 mg/L) for 21 days under growth chamber conditions. Estimates of malondialdehyde, hydrogen peroxide contents, and antioxidant enzymes (catalase and ascorbate peroxidase) under treatment of NiO nanoparticles were assayed. The result showed that by significantly increasing the concentration of NiO nanoparticles, the activity of catalase and ascorbate peroxidase enzymes was enhanced. Malondialdehyde and hydrogen peroxide contents significantly increased in the presence of NiO nanoparticles. In this study, the increasing activity of catalase and ascorbate peroxidase was not enough for radical oxygen species detoxification.Inspec keywords: nickel compounds, molecular biophysics, biotechnology, microorganisms, nanoparticles, biochemistry, microwave materials processing, hydrogen compounds, enzymes, cellular biophysicsOther keywords: solid‐state microwave irradiation, synthesised NiO nanoparticles, soybean, facile microwave‐assisted synthesis, biochemical factors, Murashige, Skoog agar medium, malondialdehyde, hydrogen peroxide contents, antioxidant enzymes, ascorbate peroxidase enzymes, radical oxygen species detoxification, NiO, [Ni(NH₃)₆](NO₃)₂      

Preparation of monodisperse Ni nanoparticles and their assembly into 3D nanoparticle superlattices

Monodisperse Ni nanoparticles with sizes varying from 4.8 to 11.3 nm are prepared via a one-pot reaction that involves the reduction of nickel(II) acetylacetonate in oleylamine in the presence of trioctylphosphine and 1,2-hexadecanediol. Reaction parameters such as temperature and the concentration of capping agent and metal precursor are critical for the adjustment of particle size. The decrease of crystallinity is observed for the samples with smaller particle sizes, which significantly affects the magnetic properties. Three-dimensional (3D) superlattices that are composed of Ni nanoparticles with different sizes are obtained on different substrates by a facile self-assembly process, and are characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM) and small-angle X-ray diffraction (SAXRD). The Ni nanoparticle superlattices formed on carbon-coated TEM copper grids exhibit a dominant hexagonal close-packed (hcp) symmetry, although local fcc packing is also occasionally observed. The formation of 3D nanoparticle superlattice structures on Si substrates is confirmed from the SAXRD measurements. The method revealed in this study for the preparation of 3D superlattices composed of Ni nanoparticles with tunable sizes offers the potential to explore their interesting collective properties for multiple applications.     

Influence of surface modification by 2-aminothiophenol on optoelectronics properties of ZnO nanoparticles

In this study, a precipitation method was used to synthesise ZnO nanoparticles using suitable precursors. An efficient surface modification method was proposed in order to reduce the agglomeration among synthesised small sized ZnO nanoparticles using 2-aminothiophenol as a capping agent. This article briefly investigated the effects of capping agent like 2-aminothiophenol on the optoelectronic properties of ZnO nanoparticles. The modified effectivity of 2-aminothiophenol has been examined on the nanosized ZnO nanoparticle for fluorescence and UV–visible (UV–vis) studies. The mechanism was studied for ZnO nanoparticles light emitting capability under different conditions. By facilitating the capping of ZnO with 2-aminothiophenol, fluorescence emission of the surface defects vanishes and ultraviolet (UV) emission increases. Surface capping by 2-aminothiophenol effectively covers most of the surface defects of ZnO and results in quenching of the visible region. The UV–vis absorption spectra of modified ZnO nanoparticles has been influenced by modified ZnO nanoparticles as a result of surface modification; where marked blue shift in absorption edge results. By surface modification of ZnO nanoparticles, change in optoelectronics properties has opened the new scope and possibilities to explore and fine tune the optical character of the modified ZnO for various optoelectronics applications such as UV laser.     

Assembly of Ni(OH)2 nanoparticle films on aqueous surfaces induced by small amounts of toluene, and the study of their unmediated electrocatalytic oxidation toward some small biomolecules

A simple strategy for the preparation of a Ni(OH)2 nanoparticle film is described. Ni(OH)2 nanoparticles were synthesized in an aqueous solution of Ni2+ and tert-butylamine in the presence of small amounts of toluene, which induced the nanoparticles to assemble a thin film on the aqueous surface. The obtained Ni(OH)2 nanoparticle film was easily transferred onto the electrode surfaces and exhibited stable electrochemical performance. The electrochemical behavior of various small biomolecules, including cysteine, homocysteine, glutathione, histidine, glycine, cystine, methionine, lysine, aspartic acid, glutamic acid, phenylalanine, ascorbic acid, uric acid and dopamine, were studied at the Ni(OH)2 nanoparticle-film-modified electrode. The Ni(OH)2 nanoparticle film exhibits excellent direct, unmediated electrocatalysis toward the oxidation of cysteine, homocysteine and ascorbic acid in a pH 7.4 buffer solution with a low onset potential and a high oxidation signal. This behavior differs from many reports in which small organic molecules are electrocatalyzed indirectly by the Ni(OH)2/NiOOH redox couple in a strongly alkaline solution.     

Cellular uptake of gold nanoparticles passivated with BSA-SV40 large T antigen conjugates

Internalization and subcellular localization in HeLa cells of gold nanoparticles modified with the SV40 large T antigen were quantified using inductively coupled plasma optical emission spectroscopy (ICP-OES). Internalization was monitored as a function of incubation time, temperature, nanoparticle diameter, and large T surface coverage. Increasing the amount of large T peptides per gold nanoparticle complex, by either increasing the coverage at constant nanoparticle diameter or by increasing the nanoparticle diameter at constant large T coverage, resulted in more cellular internalization. In addition, nuclear fractionation was performed to quantify nuclear localization of these complexes as a function of large T coverage. In contrast to our prior qualitative investigations of nuclear localization by video-enhanced color differential interference contrast microscopy (VEC-DIC), ICP-OES was able to detect nanoparticles inside fractionated cell nuclei. Although increasing the large T coverage was found to afford higher cell internalization and nuclear targeting, quantitative evaluation of cytotoxicity revealed that higher large T coverages also resulted in greater cytotoxicity. The ICP-OES and nuclear fractionation techniques reported here are valuable tools that can add important quantitative information to optical and electron imaging methods such as VEC-DIC and transmission electron microscopy regarding the fate of nanoparticles in cells.     

In vitro biological activities of anionic gamma-Fe2O3 nanoparticles on human melanoma cells

Three magnetic fluid (MF) samples containing gamma-Fe2O3 (maghemite) nanoparticles surface-coated with either meso-2,3-dimercaptosuccinic acid (DMSA), citric acid or lauric acid were prepared, characterized, and assessed for their cytotoxic potential on the human SK-MEL-37 melanoma cell line. Ultra-structural analysis was also performed using transmission electron microscopy (TEM). In vitro cytotoxicity was evaluated by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The inhibitory concentration (IC50) derived from the sigmoidal dose response curve was 254 microg-iron/mL (95% confidence interval 239-270 microg-iron/mL) for lauric acid-coated nanoparticles. DMSA-coated nanoparticles did not exhibit a clear trend toward toxicity (IC50 value is more than 2260 +/- 50 microg-iron/mL) and the IC50 value was about 433 +/- 14 microg-iron/mL for citric-acid coated nanoparticles. The cytotoxic response correlated with both the hydrodynamic diameter and the zeta potential suggests that the chain length of the carboxylic acid of the coating species may influence metabolic cellular process. Also the assayed nanoparticles can be considered non-cytotoxic to human melanoma cells since IC50 values are higher than plasma concentration usually observed in clinical use of contrast agents. Using TEM we verified that all assayed nanoparticles were internalized by cells through endocytic vesicles. Additionally, cells treated with lauric acid-coated nanoparticles at high concentration (588 or 840 microg-iron/mL) displayed morphological features of apoptosis (surface blebbing, intense vacuolization and chromatin condensation) or a typical DNA ladder pattern when analyzed by TEM or agarose gel electrophoresis, respectively. Apoptotic events may be operative, suggesting a promising therapeutic application for the lauric acid-coated nanoparticle in the treatment of cancer cells.     

Synthesis and characterization of supported polysugar-stabilized palladium nanoparticle catalysts for enhanced hydrodechlorination of trichloroethylene

Palladium (Pd) nanoparticle catalysts were successfully synthesized within an aqueous phase using sodium carboxymethyl cellulose (CMC) as a capping ligand which offers a green alternative to conventional nanoparticle synthesis techniques. The CMC-stabilized Pd nanoparticles were subsequently dispersed within support materials using the incipient wetness impregnation technique for utilization in heterogeneous catalyst systems. The unsupported and supported (both calcined and uncalcined) Pd nanoparticle catalysts were characterized using transmission electron microscopy, energy dispersive x-ray spectrometry, x-ray diffraction, and Brunauer-Emmett-Teller surface area measurement and their catalytic activity toward the hydrodechlorination of trichloroethylene (TCE) in aqueous media was examined using homogeneous and heterogeneous catalyst systems, respectively. The unsupported Pd nanoparticles showed considerable activity toward the degradation of TCE, as demonstrated by the reaction kinetics. Although the supported Pd nanoparticle catalysts had a lower catalytic activity than the unsupported particles that were homogeneously dispersed in the aqueous solutions, the supported catalysts retained sufficient activity toward the degradation of TCE. In addition, the use of the hydrophilic Al(2)O(3) support material induced a mass transfer resistance to TCE that affected the initial hydrodechlorination rate. This paper demonstrates that supported Pd catalysts can be applied to the heterogeneous catalytic hydrodechlorination of TCE.     

Cytotoxic effects of MgO nanoparticles on human umbilical vein endothelial cells in vitro

The MgO nanoparticles are widely used in many fields. However, the toxicity of these nanoparticles to cells and organs remains fairly undiscovered. In this study, the cytotoxicity of MgO nanoparticles on human umbilical vein endothelial cells (HUVECs) in vitro was examined. The morphology and size of MgO nanoparticles were analysed by the transmission electron microscope (TEM) and nanoparticle size analyser. MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2?h-tetrazolium bromide) assay, 4',6-diamidino-2-phenylindole (DAPI) staining analysis, NO release and total antioxidation competence (T-AOC) assay were used to evaluate the cytotoxicity of MgO nanoparticles. The results showed that most MgO nanoparticles were spherical with agglomerated state and the diameter of single particle was about 100?nm. Meanwhile, low concentration (below 200?[micro sign]g/ml) of MgO nanoparticles suspension showed no cytotoxicity by MTT assay. However, once the concentration of MgO nanoparticles was higher than 500?[micro sign]g/ml, the relative growth rate was lower than the control. The DAPI staining analysis results showed no significant difference of the cells morphology between the groups with or without MgO nanoparticles. In addition, the MgO nanoparticles significantly enhanced the NO release and T-AOC content of the HUVECs. The testing results indicated that low concentration of MgO nanoparticles exhibited non-cytotoxicity.     

Melting of Ni and Fe nanoparticles: a molecular dynamics study with application to carbon nanotube synthesis

Molecular dynamics simulations with many-body interatomic potentials are used to study melting of Ni and Fe nanoparticles with diameters that range between 2 and 12 nm. Two different embedded-atom method interatomic potentials are used for each element. The capability of each interatomic potential to model (i) size-dependent melting in nanoparticles and (ii) the bulk melting temperature of Ni or Fe is explored. In agreement with existing theory, molecular dynamics simulations show that the melting temperature of non-supported nanoparticles decreases with decreasing nanoparticle size, displaying a linear relationship with the inverse of nanoparticle diameter. However, molecular dynamics simulations using the interatomic potentials considered in this work provide a lower estimate than existing theory for the sensitivity of the melting temperature to nanoparticle size (slope of linear relationship). Molecular dynamics simulations demonstrate that melting is surface initiated and that a finite temperature range exists in which partial melting of the nanoparticle occurs. This observation is very important in the development of advanced vapor-liquid-solid models for catalyst-assisted single-walled carbon nanotube synthesis.     

The influence of the surface chemistry of silver nanoparticles on cell death

The influence of the surface chemistry of silver nanoparticles (AgNPs) on p53 mediated cell death was evaluated using human dermal fibroblast (HDF) and lung cancer (A549) cells. The citrate reduced AgNPs (C-AgNPs) were modified with either lactose (L-AgNPs) or a 12-base long oligonucleotide (O-AgNPs). Both unmodified and modified AgNPs showed increased concentration and time dependent cytotoxicity and genotoxicity causing an increased p53 up-regulation within 6 h and led to apoptotic or necrotic cell deaths. The C-AgNPs induced more cytotoxicity and cellular DNA damage than the surface modified AgNPs. Modifying the C-AgNPs with lactose or the oligonucleotide reduced both necrotic and apoptotic cell deaths in the HDF cells. The C-AgNPs caused an insignificant necrosis in A549 cells whereas the modified AgNPs caused necrosis and apoptosis in both cell types. Compared to the O-AgNPs, the L-AgNPs triggered more cellular DNA damage, which led to up-regulation of p53 gene inducing apoptosis in A549 cells compared to HDF cells. This suggests that the different surface chemistries of the AgNPs cause different cellular responses that may be important not only for their use in medicine but also for reducing their toxicity.     

Uptake of silica-coated nanoparticles by HeLa cells

Nanoparticles have seen wide applications in cellular research and development. One major issue that is unclear is the uptake of nanoparticles by cells. In this study, we have investigated the uptake of silica-coated nanoparticles by HeLa cells, employing rhoadime 6G isothiocyanate (RITC)-doped nanoparticles as a synchronous fluorescent signal indicator. These nanoparticles were synthesized with reverse microemulsion. A few factors, such as nanoparticle concentration, incubation time and temperature, and serum and inhibitors in culture medium were assessed on the nanoparticle's cellular uptake. The experimental results demonstrated that uptake was maximum after a 6 h incubation and was higher at 37 degrees C than that at 4 degrees C. Nanoparticle uptake depended on the nanoparticle concentration and was inhibited by hyperosmolarity, K+ depletion. In addition, serum in culture medium decreased the cellular uptake of nanoparticles. The results indicated that the uptake of silica-coated nanoparticles by HeLa cells was a concentration-, time-, and energy-dependent endocytic process. Silica-coated nanoparticles could be transported into HeLa cells in part through adsorptive endocytosis and in part through fluid-phase endocytosis.     

One-pot solvothermal synthesis of size-controlled NiO nanoparticles

In this work, NiO nanoparticles with diameter of ～4.5?nm for application as electrode material in supercapacitor were directly synthesized by an one-pot solvothermal strategy using N,N-dimethylformamide (DMF) as solvent and hexadecyl trimethyl ammonium bromide (CTAB) as additive. The experiment results indicated that CTAB is the key for the phase formation of NiO. Ni(OH)₂ phase was formed in the absence of CTAB, while NiO phase was produced in the presence of CTAB as an additive. As compared with the NiO prepared by calcination on the layer-structured Ni(OH)₂ intermediate produced in the absence of CTAB, the NiO nanoparticles prepared by this strategy had smaller particle size. Due to large specific surface area, small size and residual Ni(OH)₂, these NiO nanoparticles presented high electrochemical performance. They had high specific capacitance of 1128?F?g^?1 at low current density of 3.1?A?g^?1 and 625.0?F?g^?1 at high current density of 62.5?A?g^?1.     

Importance of nanoparticle size in colorimetric and SERS-based multimodal trace detection of Ni(II) ions with functional gold nanoparticles

Colorimetric detection of analytes using gold nanoparticles along with surface-enhanced Raman spectroscopy (SERS) are areas of intense research activity since they both offer sensing of very low concentrations of target species. Multimodal detection promotes the simultaneous detection of a sample by a combination of different techniques; consequently, surface chemistry design in the development of multimodal nanosensors is important for rapid and sensitive evaluation of the analytes by diverse analytical methods. Herein it is shown that nanoparticle size plays an important role in the design of functional nanoparticles for colorimetric and SERS-based sensing applications, allowing controlled nanoparticle assembly and tunable sensor response. The design and preparation of robust nanoparticle systems and their assembly is reported for trace detection of Ni(II) ions as a model system in an aqueous solution. The combination of covalently attached nitrilotriacetic acid moieties along with the L-carnosine dipeptide on the nanoparticle surface represents a highly sensitive platform for rapid and selective detection of Ni(II) ions. This systematic study demonstrates that significantly lower detection limits can be achieved by finely tuning the assembly of gold nanoparticles of different core sizes. The results clearly demonstrate the feasibility and usefulness of a multimodal approach.     

Electrospun N‐Doped Porous Carbon Nanofibers Incorporated with NiO Nanoparticles as Free‐Standing Film Electrodes for High‐Performance Supercapacitors and CO2 Capture

Carbon nanofibers (CNF) with a 1D porous structure offer promising support to encapsulate transition‐metal oxides in energy storage/conversion relying on their high specific surface area and pore volume. Here, the preparation of NiO nanoparticle‐dispersed electrospun N‐doped porous CNF (NiO/PCNF) and as free‐standing film electrode for high‐performance electrochemical supercapacitors is reported. Polyacrylonitrile and nickel acetylacetone are selected as precursors of CNF and Ni sources, respectively. Dicyandiamide not only improves the specific surface area and pore volume, but also increases the N‐doping level of PCNF. Benefiting from the synergistic effect between NiO nanoparticles (NPs) and PCNF, the prepared free‐standing NiO/PCNF electrodes show a high specific capacitance of 850 F g^?1 at a current density of 1 A g^?1 in 6 m KOH aqueous solution, good rate capability, as well as excellent long‐term cycling stability. Moreover, NiO NPs dispersed in PCNF and large specific surface area provide many electroactive sites, leading to high CO₂ uptake, and high‐efficiency CO₂ electroreduction. The synthesis strategy in this study provides a new insight into the design and fabrication of promising multifunctional materials for high‐performance supercapacitors and CO₂ electroreduction.