Nanoparticle Electrodes Research Articles

Synthesis of Co4N nanoparticles via a urea-glass route toward bifunctional cathode for high-performance Li−O2 batteries

Rechargeable lithium–oxygen (LiO2) batteries are considered as one of the most ideal energy storage devices because of their high theoretical energy density. However, the practical application of LiO2 batteries is hindered by their slow reaction kinetics and various notorious side reactions, which causing inferior redox overpotentials. Herein, Co4N nanoparticles electrode with low agglomeration by using a urea–glass route at moderate temperatures is proposed to address the above challenges. It shows high electron conductivity since it retained metallic cobalt crystal structure. In addition, the efficiently catalytic activity of Co4N can effectively suppress side reactions by reducing the charging polarization and expand the reaction kinetics. The DFT results demonstrate that the electronic structure change of Co4N crystal plays an important role in improving ORR activity. The overpotential for ORR increases in Co4N/N-CNTs is much easier to implement within the applied potential, and thus leading to a better catalytic performance toward ORR. Meanwhile, coupling with nitrogen can effectively optimize the electronic structure of Co4N sites in N-CNTs, thereby reducing the energy barrier of reaction intermediates to promote the reversible ORR kinetics process. Benefiting from the above advantages, the Co4N/N-CNTs delivers improved long-term cycling stability (80 cycles under O2 atmosphere) under the capacity limited at 500 mAh g−1 and current density at 200 mA g−1. This work suggests an effective pathway to fabricate the metal nitrides with efficiently catalytic activity.

Engineering copper nanoparticle electrodes for tunable electrochemical reduction of carbon dioxide

Engineering copper nanoparticle electrodes for tunable electrochemical reduction of carbon dioxide

Ru-Doped Co3O4 Nanoparticles as Efficient and Stable Electrocatalysts for the Chlorine Evolution Reaction.

The electrochemical chlorine evolution reaction (CER) is one of the most important electrochemical reactions. Typically, iridium (Ir)- or ruthenium (Ru)-based mixed metal oxides have been used as electrocatalysts for the CER due to their high activities and durabilities. However, the scarcity of Ir and Ru has indicated the need to develop alternative earth-abundant transition-metal-based CER catalysts. In this study, we report a Co3O4 nanoparticle (NP) catalyst synthesized by a hydrothermal method. Furthermore, Ru was successfully incorporated into the Co3O4 NPs (RuxCo3-xO4 NPs) for further improvement of catalytic performance in chlorine generation. Electrokinetic analyses combined with in situ X-ray absorption near-edge structure (XANES) results suggested an identical CER mechanism for the Co3O4 NPs and RuxCo3-xO4 NPs. Various characterization techniques demonstrated that the homogeneous substitution of Ru4+ ions into the Co3+ octahedral sites enhanced the structural disorder and changed the electronic state of Co3O4, resulting in additional exposed active sites. Remarkably, the Ru0.09Co2.91O4 NP electrode exhibited outstanding stability for more than 150 h even at a high current density of 500 mA/cm2, which shows its commercial viability for active chlorine generation.

Control of Nanoparticle Dispersion, SEI Composition, and Electrode Morphology Enable Long Cycle Life in High Silicon Content, Nanoparticle-Based Composite Anodes for Lithium-Ion Batteries

Striking a balance between high theoretical capacity, Earth abundance, and compatibility with existing manufacturing infrastructure, silicon is one of the few materials that meets the requirements for a next-generation anode for rechargeable lithium-ion batteries. Due to complications with extreme volume changes during charging/discharging and reactive interfacial chemistries, however, the cycle-life of silicon-based composite anodes is unacceptable for broad use. Developing a majority silicon composite anode formulation that overcomes these challenges and is compatible with current industry manufacturing practices requires materials and chemical engineering solutions that account for both electrode morphology and interfacial chemistry. Here, we synthesize surface-functionalized silicon nanocrystals that enable a highly dispersed and homogeneous slurry that can easily be integrated into standard electrode fabrication process. We use this formulation to print a 76 wt. % silicon composite electrode. We show that the contents and the morphology of the silicon electrolyte interphase – a determining factor in the cycle life of silicon-based anodes – can be controlled with a post-synthetic thermal curing procedure. When paired against a capacity-matched lithium nickel manganese cobalt oxide LiNi0.8Mn0.1Co0.1O2 cathode, the cell retains 72% of its capacity through 1000 charge/discharge cycles while delivering an initial anode specific capacity of nearly 1000 mAh/g and an areal capacity of 2.55 mAh/cm2. Figure 1

Porosity Engineering of Si Nanoparticle-Based Electrodes by Carbon Nanostructures

Silicon (Si) has been considered as a next-generation anode material due to natural abundance, low operating potential (<0.5 V vs. Li/Li+), and high theoretical specific capacity of 4200 mAh g-1.1 However, the electrochemical alloying reaction of Si involves large volume changes of 400% during lithiation and delithiation, causing cracking and pulverization of Si.1 In addition, solid electrolyte interface (SEI) of Si anode experiences constant changes due to unstable SEI reactivity.2 Considerable efforts have been made to design nanostructured Si materials to address the issues because nanostructuring can relieve the mechanical strain.3 However, when compared to micrometer-sized active materials having sufficient electrolyte pathway through interparticle space, the nanoparticle (NP)-based electrodes tend to be densely packed. As mass loading is higher and electrode is thicker, ion transport issue can become more severe in the densely packed electrodes.4 In this work, we will present studies on engineered porosity impacts performance in Si NP electrodes by altering porosity with carbon nanostructures. We explore the extreme limit of effectively non-porous electrodes using quasi-spherical, 6 nm diameter Si NPs produced via plasma-enhanced chemical vapor deposition (PECVD), which result in densely packed electrodes when slurry is prepared with conventional carbon black. We engineer porosity using carbon nanostructures including single-walled carbon nanotubes and carbon nanorods in place of conventional carbon black to create pore structure in Si NP-based electrodes. These experiments provide a correlation between mass loading, porosity and silicon utilization in Si NP-based electrodes.

Platinum and palladium nanoparticles on boron-doped diamond for the electrochemical detection of hydrogen peroxide: a comparison study.

Hydrogen peroxide (H2O2) plays a role in many facets - a household item, an important industrial chemical, a biomarker in vivo, and several others. For this reason, its measurement and quantification in a variety of media are important. While spectroscopic detection is primarily used for H2O2, electrochemical methods offer advantages in versatility, cost, and sensitivity. In this work, we investigate a 2-step surface metal nanoparticle (NP) modification for platinum (Pt) and palladium (Pd) on boron-doped diamond (BDD) electrodes for the detection of H2O2. Several parameters such as the metal salt concentration and electrodeposition charge in the 2-step modification were varied to find an optimum. Using cyclic voltammetry (CV), the BDD-PdNP electrode types were found to yield a sharper, more well-resolved H2O2 oxidation peak compared to the BDD-PtNP electrodes. Both metal NP electrode types significantly improved the response compared to the bare BDD electrode; a 150-200× improvement in sensitivity was observed across all modified electrode types. Calibration experiments were completed at both low and high concentration ranges in stagnant and flow-based solutions. The lowest limit of detection (LOD) obtained was 50 nM (5E-08 M) on a BDD-PdNP electrode modified with 1.0 mM PdCl2 to 5.0 mC in the wet chemical seeding and electrodeposition steps. 0.25 mM PdCl2 to 3.23 mC and 0.25 mM HPtCl6- to 3.23 mC also yielded a sufficient response for low-level H2O2, with LODs around 100 nM (1E-07 M). Overall, this work exemplifies the wide applicability of BDD and achieves sub-μM H2O2 LODs with a non-enzymatic electrode material.

Green Synthesis of Copper Oxide Nanoparticle Decorated Polypyrrole-Chitosan on Pencil Graphite Electrode for Enzyme-Free Glucose Sensors

Here we report that we use Vitis vinifera as a reducing and stabilizing agent during the green synthesis of CuO nanoparticles (NPs). Compared to chemical and physical synthesis methods, this approach is non-toxic, environmentally friendly, and inexpensive. Scanning electron microscopy (SEM-EDS), X-ray diffraction analysis (XRD), and Fourier transform infrared spectroscopy (FT-IR) and UV–visible spectroscopy were used to investigate the characteristics of the gained particles. It showed that NPs synthesized with Vitis vinifera extract had high purity and an average particle size average of 60 nm. Then, the sensor activity of materials obtained at different concentrations of copper oxide nanoparticles decorated polypyrrole-chitosan on pencil graphite electrode was investigated. PPy-Chi(2.5 mg)/PGE containing 2.5 mg CuO NP electrode exhibited a linear range at concentrations of 0.2–10.0 mM and a detection limit as low as 0.740 μM. The incorporation of CuO NPs has greatly increased the sensor activity of the surface electrode, which serves as a highly active site. In addition, the stability achieved along with excellent sensing ability in beverages means that the electrodes are suitable for practical applications.

Cu-Doped ZnO Nanoparticle Electrode for Precise and Rapid Sodium Ion Detection in Water Samples

Excessive consumption of sodium ions (Na+) can result in high blood pressure, linked to various health issues. To regulate Na+ intake and manage food flavour, it is crucial to determine the Na+ content in food in real time. Researchers have developed an electrochemical sensor that utilizes cyclic voltammetry (CV) to detect Na+ at room temperature to address this concern. The sensor used a Cu-doped ZnO-modified electrode and was found to be highly selective in detecting Na+. The Cu-doped ZnO nanoparticles (Cu-ZnONPs) were synthesized using a solution process and placed on a glassy carbon electrode (GCE). The sensor exhibited excellent sensitivity, selectivity, linear response, stability, and reproducibility in detecting Na+. It had a low detection limit of 0.1 ppm for known water samples and was successfully employed to measure Na+ levels in actual water samples. This electrochemical sensor is a valuable tool for the real-time measurement of Na+ levels in drinking water samples.

Sensitive electrochemical measurement of nitric oxide released from living cells based on dealloyed PtBi alloy nanoparticles.

Nitric oxide (NO), as a vital signaling molecule related to different physiological and pathological processes in living systems, is closely associated with cancer and cardiovascular disease. However, the detection of NO in real-time remains a difficulty. Here, PtBi alloy nanoparticles (NPs) were synthesized, dealloyed, and then fabricated to NP-based electrodes for the electrochemical detection of NO. Transmission electron microscopy (TEM), small-angle X-ray scattering (SAXS), and nitrogen physical adsorption/desorption show that dealloyed PtBi alloy nanoparticles (dPtBi NPs) have a porous nanostructure. Electrochemical impedance spectroscopy and cyclic voltammetry results exhibit that the dPtBi NP electrode possesses unique electrocatalytic features such as low charge transfer resistance and large electrochemically active surface area, which lead to its excellent NO electrochemical sensing performance. Owing to the higher density of catalytical active sites formed PtBi bimetallic interface, the dPtBi NP electrode displays superior electrocatalytic activity toward the oxidation of NO with a peak potential at 0.74V vs. SCE. The dPtBi NP electrode shows a wide dynamic range (0.09-31.5μM) and a low detection limit of 1nM (3σ/k) as well as high sensitivity (130 and 36.5 μA μM-1cm-2). Moreover, the developed dPtBi NP-based electrochemical sensor also exhibited good reproducibility (RSD 5.7%) and repeatability (RSD 3.4%). The electrochemical sensor was successfully used for the sensitive detection of NO produced by live cells. This study indicates a highly effective approach for regulating the composition and nanostructures of metal alloy nanomaterials, which might provide new technical insights for developing high-performance NO-sensitive systems, and have important implications in enabling real-time detection of NO produced by live cells.

A platinum nanopstructer electrode with an iodine coating is used to measure the electrochemical behavior of arctigenin using cyclic voltammetry

The cyclic voltammetric method was utilized to build an iodine-modified platinum nanoparticle electrode for measuring arctigenin electrochemically. The findings of the experiments showed that this modified electrode had a considerable voltammetric response to arctigenin, which was due to the electrocatalysis properties of iodide and the strong conductivity and large specific surface area of the platinum nanostructure electrode. The proposed approach demonstrated a broad linear range, good sensitivity, low detection limit and high selectivity. The examination of the scan rate change revealed that the electrode process is adsorption-controlled. The oxidation of arctigenin was demonstrated to involve both protons and electrons. Finally, this method can be used to develop a sensitive arctigenin detection sensor. Keywords: Volumetric sensor, Iodine-coated, Nanoparticle, Arctigenin, Platinum electrode, Iodide, Electrocatalytic ability.

Uncoupling nanoparticle geometry from material properties for improved hole injection at submonolayer nanoparticle electrode interlayers in organic hole-only devices

Uncoupling nanoparticle geometry from material properties for improved hole injection at submonolayer nanoparticle electrode interlayers in organic hole-only devices

Synthesis of ceria nanoparticles for the catalytic activity of cyclohexene epoxidation and selective detection of nitrite

Based on a few noteworthy features, cerium oxide nanoparticles have gained significance in nanotechnology. The effective microwave combustion method (MCM) and the conventional sol–gel (CRSGM) technologies are used in this study to successfully generate the crystalline CeO2 nanoparticles (NPs). Additionally, using a variety of spectroscopic and analytical methods, the synthesized CeO2 NPs are examined to assess to understand their structure and morphology. The XRD patterns of CeO2 NPs show that the structure exhibits a face-centered cubic lattice. Then, with demonstrated good conversion and selectivity, the impact of the epoxidation reaction of cyclohexene was examined. Finally, it can be said that using CeO2 nanoparticles is an efficient strategy to increase the catalytic activity toward the epoxidation reaction of cyclohexene. In the presence of acetonitrile as a solvent and H2O2 as an oxidant, the catalyst samples utilized in the cyclohexene epoxidation reaction were examined. In this study, the CeO2 catalyst outperformed all other catalysts in terms of cyclohexene maximal conversion and selectivity. After six prolonged cycles, the conversion of cyclohexene oxidation using CeO2 NPs shows reasonable recyclability and conversion efficiency, making it the best catalyst for an industrial production application.Additionally, the upgraded CeO2 nanoparticle electrode for nitrite detection has a linear concentration range (0.02–1200 M), a low detection limit (0.22 M), and a higher sensitivity (1.735 A M−1 cm−2). CeO2 NPs, on the other hand, have a quick response time, excellent sensitivity, and high selectivity. Additionally, the manufactured electrode is used to find nitrite in various water samples. Finally, it can be said that using CeO2 NPs is an efficient strategy to increase the catalytic activity toward cyclohexene oxidation and nitrite.

Helianthus-annuus assisted synthesis of ZrO2 nanoparticles: Enhanced electrochemical, photoluminescent, and optical properties

Cubic-phase ZrO2 nanoparticle (NPs) were synthesized using a cost-effective single-pot green combustion method and Helianthus annuus extract, and their properties were evaluated. Powder X-ray diffraction was used to investigate the purity, crystal structure, and size of the NPs, and the average size of the NPs was determined to be ∼ 25 nm. The internal surface morphology of the NPs with distinct voids and pores were observed using scanning electron microscopy (SEM) Ultraviolet–visible (UV-vis) absorption spectroscopy was used to analyze the optical properties of the as-synthesized ZrO2 NPs, and their energy bandgap was determined to be 4.5 eV. The photoluminescence (PL) spectrum of the cubic-phase ZrO2 NPs presented a broad band in the UV-vis region. The PL emission properties of the ZrO2 NPs were studied by analyzing their emission wavelength at ∼490 nm, and the results revealed that the NPs can be efficiently used for display applications. The electrochemical properties of a graphite–ZrO2 NP electrode was qualitatively analyzed by performing cyclic voltammetry (CV) and electrochemical impedance spectroscopy experiments in a three–electrode system with a 0.1 M KCl solution as the electrolyte. Our results suggested that the NPs can be used to evaluate the thermodynamics of the redox reaction, and their capacitance was determined using the CV curves of a graphite–ZrO2 working electrode at different scan rates in the range of 0.01 ∼ 0.05 V/s at room temperature. Furthermore, the photodegradation rate of Reactive Blue 4 textile dye over the as-prepared ZrO2 NPs reached 97% under UV-vis light irradiation.

The Properties of the CH3NH3PbI3/TiO2 Composite Layer Prepared from PbO-TiO2 Mesoporous Layer under Air Ambience

In TiO2-based perovskite solar cells (PSC), the preparation of the CH3NH3PbI3/TiO2 composite layer is very important, since the morphology of the perovskite adsorbed onto the surface of the TiO2 nanoparticles has decisive significance for the absorption of the incident sunlight and separation of the generated carrier. The traditional two-step spin-coating method for the deposition of CH3NH3PbI3 into the porous mesoporous TiO2 layer usually suffers from filling block problems. In this study, the PbO-TiO2 mesoporous layer was prepared with various ratios of Pb:Ti in the raw materials. Morphological, optical, and element analysis of the prepared thin films indicated that Pb was gradually mixed into the TiO2 mesoporous layer with the increased Pb:Ti ratios. The element distribution characteristics of the optimal thin films showed that the distribution of Pb was uniform throughout the whole TiO2 thin film, which indicates the successful mixing of Pb into the TiO2 electrode layer. Combined with dip coating, the PbO-TiO2 mesoporous layer was prepared into a CH3NH3PbI3/TiO2 composite layer and subsequently to a solar cell device. The prepared solar cell shows a short-circuit photocurrent density of 16.4 mA/cm2, an open-circuit voltage of 900 mV, a fill factor of 61%, and a power conversion efficiency (PCE) of 9.00%. The PCE of the PSC is promoted by nearly 25% when compared with that prepared with the traditional method. The proposed preparation method that combines TiO2 nanoparticle electrode with a mixing and dip coating provides a new effective way to improve the deposition of perovskite into the mesoporous TiO2 layer, which is very helpful for the fabrication of high-efficiency and low-cost PSC.

Review: Electrochemiluminescence of Perovskite-Related Nanostructures

Perovskite nanostructures are promising nanomaterials for their possible application in electrochemiluminescent (ECL) analytical systems due to their unique optical, electronic, and chemical properties. This review focuses on the most recent advances in the application of perovskite and perovskite-related nanostructures, with different chemical compositions and modifications, in ECL with various media, coreactants, and reaction types. The most optimal methods of perovskite nanoparticle synthesis and electrode modification methods were reviewed. Possibilities and perspectives of the use of perovskite-related nanostructures for the ECL generation were demonstrated.

Noble-Metal-Free Zinc Oxide Nanoparticle Electrodes for Electrochemical Detection of Benzene-Derived Compounds: 2,4,6-trinitrotoluene, 2,4-dinitrotoluene, and diphenylamine

Zinc oxide nanoparticle electrode catalysts were used to electrochemically examine benzene-derived compounds by controlling geometric factors (particle size and oxide-layer thickness) to measure the detection sensitivity difference. Spin-coating was performed to control the nanoparticle layer thickness. First, a representative benzene-derived compounds (2,4,6-trinitrotoluene) was detected using cyclic voltammetry. Three main cathodic reduction peaks were confirmed in the range of −0.5 to −0.9 V (vs Ag/AgCl in 3 M KCl). 50 nm diameter and ∼2 μm thickness of zinc oxide nanoparticles appeared the best detection performance, due to the surface uniformity, high surface area, and electric conductivity. Two additional benzene-derived compounds (2,4-dinitrotoluene and diphenylamine) were utilized to measure the detectability of the zinc oxide nanoparticle layers. Consequently, 2,4-dinitrotoluene and diphenylamine were detected using cyclic voltammetry. The mass transfer of these three benzene-derived compounds affected the diffusion- and surface-controlled processes. Finally, the limits of detection, quantitation, and sensitivity of the benzene-derived compounds were recorded using differential pulse voltammetry. The results indicated that adjusting the geometric factor is a competitive method for enhancing the detection sensitivity. Moreover, this work can be extended to detect diverse benzene-derived compounds such as diazonitrophenol, nitrocellulose, picric acid, and tetryl.

Facile fabrication of laser induced versatile graphene-metal nanoparticles electrodes for the detection of hazardous molecules

In this work, we developed a facile method to fabricate laser induced versatile graphene-metal nanoparticles (LIG-MNPs) electrodes with redox molecules sensing capabilities. Unlike conventional post-electrodes deposition, versatile graphene-based composites were engraved by a facile synthesis process. As a general protocol, we successfully prepared modular electrodes including LIG-PtNPs and LIG-AuNPs and applied them to electrochemical sensing. This facile laser engraving process enables rapid preparation and modification of electrodes, as well as simple replacement of metal particles modification towards varied sensing targets. The LIG-MNPs showed high sensitivity towards H2O2 and H2S due to their excellent electron transmission efficiency and electrocatalytic activity. By simply changing the types of coated precursors, the LIG-MNPs electrodes have successfully achieved real-time monitoring of H2O2 released from tumor cells and H2S contained in wastewater. This work contributed a universal and versatile protocol for quantitatively detecting a wide range of hazardous redox molecules.

Overcoming the Trade-Off between Optical Transmittance and Areal Capacitance of Transparent Supercapacitors for Practical Application.

It is substantially challenging for transition metal oxide nanoparticle (NP)-based electrodes for supercapacitors to achieve high transparency and large capacity simultaneously due to the inherent trade-off between optical transmittance (T) and areal capacitance (CA ). This study demonstrates how this trade-off limitation can be overcome by replacing some electrode NPs with transparent tin oxide (SnO2 ) NPs. Although SnO2 NPs are non-capacitive, they provide effective paths for charge transport, which simultaneously increase the CA and T550nm of the manganese oxide (Mn3 O4 ) NP electrode from 11.7 to 13.4 mF cm-2 and 82.1% to 87.4%, respectively, when 25 wt% of Mn3 O4 are replaced by SnO2 . The obtained CA values at a given T are higher than those of the transparent electrodes previously reported. An energy storage window fabricated using the mixed-NP electrodes exhibits the highest energy density among transparent supercapacitors previously reported. The improved energy density enables the window to operate various electronic devices for a considerable amount of time, demonstrating its applicability in constructing a reliable and space-efficient building-integrated power supply system.

Kappa-carrageenan for benign preparation of CdSeNPs enhancing the electrochemical measurement of AC symmetric supercapacitor device based on neutral aqueous electrolyte

This study presents the development of an electrochemical supercapacitor with a cadmium selenide nanoparticles (CdSeNPs) electrode utilizing a straightforward and economical method based on kappa-carrageenan (κ-CGN). The structural, morphological, and optical characteristics of CdSeNPs were assessed. Activated carbon (AC) and green-prepared CdSeNPs were easily mixed to achieve excellent electrochemical properties. The nanoelectrode (AC@CdSe) was tested in an aqueous electrolyte of sodium sulfate (Na2SO4) with a concentration of 1 Molar. Specific capacitance (Csp) for the AC electrode and the AC@CdSe electrode at 1 A g−1 was calculated to be 103 and 480 F g−1, respectively. Besides, the symmetric supercapacitor AC@CdSe/AC@CdSe device has a high specific energy of 52 Wh kg−1 and a maximum specific power of 2880 W kg−1, with a specific capacitance of 115.5 F g−1. With a coulombic efficiency of between 82 % and 100 %, the device continues to maintain excellent capacitance after 10.000 cycles.

Analytical Study of Zinc Sulphide Electrode Prepared from Nano material

Zinc Sulphide nanoparticles (NPs) has been prepared from raw material by microwave method. ZnS NPs were characterized by X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM), The size of ZnS NPs were about (3.15nm) calculated from the Scherer formula from the most intense XRD peak, The calculated product for ZnS was about 94.4%.Zn2+-selective electrode based on poly vinyl chloride (PVC) was prepared by using ZnS Nanoparticles (NPs) powders and di-butyl phthalate, and were compared The analytical specifications of ZnS NPs and ZnS Microparticles (Non- NPs ) electrode. ZnS NPs electrode and ZnS Non- NPs electrode give linear range upon (10-5-10-2)M and (10-4-10-2)M, Nernstain slope of (30.35 mV/decade) and (30.84 mV/decade), correlation coefficient of (0.9999) and (0.9995), detection limit of (1.733x10-7)M and (2.486x10-6)M, quantitative limit of (5.77x10-7)M and (7.07x10-6)M, the response time of (9-39) second and (13-36) second, respectively. The lifetime for each electrode was 15 days. The optimum conditions for each electrode were (5-7), (20-30 ̊C) and (10-4) M for pH, temperature and concentration of filling solution respectively. The selectivity of electrodes were measured using mixed solutions method, the results showed that the selectivity coefficient values for all interferences ions are less than one.