Oxide Nanoplates Research Articles

Enhanced Charge Storage Performance and Electrocatalytic Oxygen Evolution Reaction Activity of Self-Grown Iron–Cobalt-Doped Nickel Oxide Nanoplates: An Example of the Synergistic Effect

Enhanced Charge Storage Performance and Electrocatalytic Oxygen Evolution Reaction Activity of Self-Grown Iron–Cobalt-Doped Nickel Oxide Nanoplates: An Example of the Synergistic Effect

Synergistic effects of multi-dimensionality in an aerogel for lithium-ion battery anodes with an enhanced capacitive contribution

The rational design of anode materials is important when seeking to produce high-performance lithium-ion batteries (LIBs) that offer both a high-power density (P) and a high energy density (ε). In this study, a multi-dimensional aerogel composed of 1-dimensional (1D) and two-dimensional (2D) nanostructures was synthesized. To impart conductivity and dimensional diversity, reduced graphene oxide (rGO) nanoplates were introduced to a 1D Co-S aerogel using a metal coordination-assisted sol–gel method. As the anode material for an LIB, the resulting multi-dimensional rGO@Co-S aerogel with 1.4 wt% GO exhibited outstanding electrochemical performance, with a high specific capacity, high-rate capability, strong cycling stability (84 % at 0.5 A/g after 350 cycles), an excellent P (9,660 W/kg), and a high ε (1,566 Wh/kg). This was attributed to the shorter ion and electron diffusion paths arising from the multi-dimensional structure, coupled with the higher surface area and enhanced capacitive contribution due to the addition of the rGO nanoplates.

Two-dimensional single-crystalline mesoporous high-entropy oxide nanoplates for efficient electrochemical biomass upgrading.

Mesoporous single crystals have received more attention than ever in catalysis-related applications due to their unique structural functions. Despite great efforts, their progress in engineering crystallinity and composition has been remarkably slower than expected. In this manuscript, a template-free strategy is developed to prepare two-dimensional high-entropy oxide (HEO) nanoplates with single-crystallinity and penetrated mesoporosity, which further ensures precise control over high-entropy compositions and crystalline phases. Single-crystalline mesoporous HEOs (SC-MHEOs) disclose high electrocatalytic performance in 5-hydroxymethylfurfural oxidation reaction (HMFOR) for efficient biomass upgrading, with remarkable HMF conversion of 99.3% and superior 2,5-furandicarboxylic acid (FDCA) selectivity of 97.7%. Moreover, with nitrate reduction as coupling cathode reaction, SC-MHEO realizes concurrent electrosynthesis of value-added FDCA and ammonia in the two-electrode cell. Our study provides a powerful paradigm for producing a library of novel mesoporous single crystals for important catalysis-related applications, especially in the two-electrode cell.

Ultrafine Pt Nanoparticles on Defective Tungsten Oxide for Photocatalytic Ethylene Synthesis.

The selective conversion of ethane (C2H6) to ethylene (C2H4) under mild conditions is highly wanted, yet very challenging. Herein, it is demonstrated that a Pt/WO3-x catalyst, constructed by supporting ultrafine Pt nanoparticles on the surface of oxygen-deficient tungsten oxide (WO3-x) nanoplates, is efficient and reusable for photocatalytic C2H6 dehydrogenation to produce C2H4 with high selectivity. Specifically, under pure light irradiation, the optimized Pt/WO3-x photocatalyst exhibits C2H4 and H2 yield rates of 291.8 and 373.4µmolg-1h-1, respectively, coupled with a small formation of CO (85.2µmolg-1h-1) and CH4 (19.0µmolg-1h-1), corresponding to a high C2H4 selectivity of 84.9%. Experimental and theoretical studies reveal that the vacancy-rich WO3-x catalyst enables broad optical harvesting to generate charge carriers by light for working the redox reactions. Meanwhile, the Pt cocatalyst reinforces adsorption of C2H6, desorption of key reaction species, and separation and migration of light-induced charges to promote the dehydrogenation reaction with high productivity and selectivity. In situ diffuse reflectance infrared Fourier transform spectroscopy and density functional theory calculation expose the key intermediates formed on the Pt/WO3-x catalyst during the reaction, which permits the construction of the possible C2H6dehydrogenation mechanism.

The construction of a flexible solid-state asymmetric supercapacitor device using nickel-copper oxide nanoplates and carbon nanosphere serving as positive and negative electrode, respectively with excellent electrochemical capabilities

Here, nickel-copper oxide nanoplates (NCN) and carbon nanosphere (CNS) as positive and negative electrodes are synthesised via a hydrothermal protocol without adding any surfactant and binders. The NCN and CNS electrodes in KOH electrolyte exhibit superior specific capacitance of ∼ 2362.5 F g−1 and ∼ 246.11 F g−1 at 1 A g−1 respectively. The NCN and CNS retained 98.54 % and 97.88 % of the initial capacitance after 3000 galvanostatic charge–discharge (GCD) cycles, respectively. Additionally, an asymmetric supercapacitor (ASC) device NCN//CNS is constructed using NCN and CNS as positive and negative electrodes, utilizing poly(vinyl alcohol) PVA − KOH gel electrolyte separator. The ASC device demonstrates a maximum energy density of 50.4 Wh kg−1 (181.44 KJ kg−1) with a power density ∼ 750 W kg−1 at 1 A g−1, maintaining 90.4 % cyclic stability after 10,000 GCD cycles. The electrochemical outputs of the device present significant potential for the advancement of high-performance ASC devices in electronic applications.

Screening nano additives for favorable NOx/smoke emissions trade-off in a CRDI diesel engine fueled by industry leather waste fat biodiesel blend

The depletion of petroleum reserves and increasing environmental concerns prompted significant research into alternative fuels. This work, biodiesel, is extracted from the byproduct of industrial leather waste fat to generate beneficial energy.The main objective of this study is to enhance common rail direct injection (CRDI) diesel engine outcome characteristics by substituting industrial leather waste fat biodiesel (ILWFB) with the mixing of aluminium nitrate (Al (NO3)3) nanoparticles and graphene oxide nanoplates (GONPS) in the proportion of 50 ppm (parts per million) as catalysts to enhance ignition process. This research found that with the mixing of Al (NO3)3 nanoparticles and GONPS 50 ppm into the ILWFB blend, the in-cylinder pressure increased by 0.463% and 1.5%, and the heat release rate (HRR) improved by 4.19% and 12.04% than diesel and ILWFB blend at maximum load circumstances. Brake thermal efficiency (BTE) increased by 3.1% and 5.27%, and brake specific fuel consumption (BSFC) decreased by 3.57% and 7.14% in D50ILWFB50+Al (NO3)3 50 ppm blend and D50ILWFB50+GONPS 50 ppm blend related to diesel fuel. The carbon monoxide (CO), hydrocarbon (HC), and smoke emissions were reduced by 26.84%, 13.11%, and 5.75% in D50ILWFB50+Al (NO3)3 50 ppm blend and 38.94%, 21.31%, and 9.12% decreased in D50ILWFB50+GONPS 50 ppm blend than diesel fuel. Oxides of nitrogen (NOx) emissions marginally increased by 3.66%, 5.42%, and 8.94% in ILWFB blend, D50ILWFB50+Al (NO3)3, and D50ILWFB50+GONPSrelated to pure diesel at peak load conditions. This work concluded that the nano additives effectively enhanced BTE and decreased BSFC, CO, HC, and smoke emissions in diesel engine applications.

Effect of Graphene Oxide Localization on Morphology Development and Rheological and Mechanical Properties of Poly(lactic acid)/ethylene vinyl Alcohol Copolymer Blend Composites: A Comprehensive Study.

This study investigates the rheological, morphological, and mechanical properties of melt-processed polylactide/ethylene vinyl alcohol (70PLA/30EVOH) blend composites containing 0.25, 0.5, and 1 wt.% of graphene oxide (GO) nanoplates. Thermodynamic-based suggested the localization of nanoparticles in EVOH, SEM studies showed that the introduction of GO to the blend increased dispersed droplet size, which was attributed to the localization of GO within EVOH, as confirmed by TEM. The rheology results indicated a decrease in the elasticity for the composite containing 0.25 wt.% of GO compared to the neat blend, which was attributed to the sliding effect of the added GO nanoplatelets. However, samples containing higher amounts of GO nanoplatelets exhibited more excellent elasticity than the neat blend. The increased elasticity was suggestively attributed to the dominance of hydrodynamic interactions, the physical network of added nanoplatelets, and polymer/GO interactions over the sliding role of the GO nanoplatelets at higher loadings. In addition, the effect of the order of mixing was investigated, and the premixing of PLA and GO exhibited a decrease in the droplet radius compared to the neat blend. It was ascribed to the localization of GO nanosheets in the PLA and interface, which was confirmed by rheological results and mechanical assessments.

Synthesis of Au‐decorated WO3 nanoplates for simultaneous oxidation of RhB and reduction of Cr(VI) under visible light irradiation

AbstractTungsten oxide (WO3) nanoplates were synthesized by a simple chemical precipitation technique. These nanoplates were decorated by Au nanoparticles via photoreduction route. The obtained samples were characterized by field emission scanning electron microscopy, X‐ray diffractometry and UV–vis diffuse reflectance spectroscopy to investigate their morphological, structural and optical properties. The SEM images show the plate morphology with the size in the range of 50–150 nm, their thickness ≈10 nm; spherical‐like Au nanoparticles ≈20 nm were attached to the surface of the WO3 plates. These materials were applied for the simultaneous photocatalytic degradation of Rhodamine B (RhB) and Cr(VI) under visible light. Due to the efficient separation of photoinduced charge carriers and the enhanced visible light absorption ability, the photocatalytic performance of Au‐decorated WO3 nanoplates was higher. The main active species responsible for the photodegradation reactions were identified by different scavengers and a photocatalytic mechanism was proposed. This work represents that WO3 nanoplates are a promising candidate for the degradation of organic and inorganic pollutants from the industrial wastewater under sun light exposure.

2-Methylimidazole assisted binder-free synthesis approach for hexagonal nickel-cobalt mixed oxide nanoplate as high-rate capability electrode for supercapacitor

A binder-free synthetic approach employing a hydrothermal route followed by heat treatment has been utilized to synthesize nickel-cobalt mixed oxide. The as-prepared mixed oxide exhibits a hexagonal nanoplate morphology. It was deduced that the precursor ratios and the annealing medium significantly affected the electrochemical behavior of the respective mixed oxide sample. The binary oxide with equimolar nickel and cobalt annealed at 300 °C in an inert atmosphere exhibits an optimum specific capacitance of 1058 F g−1 at 1 A g−1 with capacity retention of 91 % at 10 A g−1. The sample shows excellent cycling stability of ∼100 % after 10,000 cycles, maintaining 95 % coulombic efficiency. The assembled asymmetric supercapacitor device with nickel-cobalt mixed oxide as the cathode and reduced graphene oxide as the anode achieved a specific capacitance of 197.5 F g−1 at 1 A g−1, retaining 63.2 % at 10 A g−1. The asymmetric supercapacitor device exhibits ∼100 % capacitance retention after 10,000 cycles, with a maximum specific energy of 17.5 Wh·kg−1 at a specific power of 800 W·kg−1.

Intermolecular interactions in graphene and oxidized graphene nanocomposites

The spatial arrangement of graphene (G) or graphene oxide (GO) nanoplate agglomerations will significantly impact the material properties of graphene-based polymer nanocomposites. Therefore, we investigated the stability of G and GO agglomerates without the presence of a polymer network using molecular dynamics (MD) simulations, which was not considered in our previous work (Reil, 2022) [15]. G and GO nanoplates, often procured in powder forms, display a significant volume difference by visual observation. To this end, MD simulations were performed to model G or GO agglomerations in the powder form, including the effects of varied plate dimensions and localized surface oxidation. G plates on average released 231 kcal/mol upon agglomerating into aligned stacks, closely matching results in the literature. Simulations of GO resulted in agglomerations of clusters of plates rather than aligned stacks, releasing on average 16 % less energy than G. The clustered arrangement of GO plate agglomerates in simulations occupied a volume approximately 7x that of the aligned stack G plates, closely replicating the experimentally determined volume ratio of 10x. This research could yield further insight into the behavior of G and GO when in the presence of various polymer networks, which could be different than in isolation.

Efficient plasmonic water splitting by heteroepitaxial junction-induced faceting of gold nanoparticles on an anatase titanium(IV) oxide nanoplate array electrode.

Plasmonic photocatalysts represented by gold nanoparticle (NP)-loaded titanium(IV) oxide (Au/TiO2) can be promising solar-to-fuel converters by virtue of their response to visible-to-near infrared light. Hitherto, Au/rutile (R)-TiO2 has been recognized as exhibiting photocatalytic activity higher than that of Au/anatase (A)-TiO2. Herein, we demonstrate that the high potential of A-TiO2 as the Au NP support can be brought out through atomic level interface control. Faceting of Au NPs is induced by a heteroepitaxial junction on an A-TiO2(001) nanoplate array (Au/A-TiO2 NPLA). Photoexcitation towards the Au/A-TiO2 NPLA electrode generates current for the water oxidation reaction at λ < 900 nm with a maximum efficiency of 0.39% at λ = 600 nm, which is much larger than the values reported so far for the usual electrodes. The striking activity of the Au/A-TiO2 NPLA electrode was rationalized using a potential-dependent Fowler model. This study presented a novel approach for developing solar-driven electrodes for green and sustainable fuel production.

Ultrasmall Cu Nanoparticles Supported on Crystalline, Mesoporous ZnO for Selective CO2 Hydrogenation

AbstractConverting CO2 to value‐added chemicals, e. g., CH3OH, is highly desirable in terms of the carbon cycling while reducing CO2 emission from fossil fuel combustion. Cu‐based nanocatalysts are among the most efficient for selective CO2‐to‐CH3OH transformation; this conversion, however, suffers from low reactivity especially in the thermodynamically favored low temperature range. We herein report ultrasmall copper (Cu) nanocatalysts supported on crystalline, mesoporous zinc oxide nanoplate (Cu@mZnO) with notable activity and selectivity of CO2‐to‐CH3OH in the low temperature range of 200–250 °C. Cu@mZnO nanoplates are prepared based on the crystal‐crystal transition of mixed Cu and Zn basic carbonates to mesoporous metal oxides and subsequent hydrogen reduction. Under the nanoconfinement of mesopores in crystalline ZnO frameworks, ultrasmall Cu nanoparticles with an average diameter of 2.5 nm are produced. Cu@mZnO catalysts have a peak CH3OH formation rate of 1.13 mol h−1 per 1 kg under ambient pressure at 246 °C, about 25 °C lower as compared to that of the benchmark catalyst of Cu−Zn−Al oxides. Our new synthetic strategy sheds some valuable insights into the design of porous catalysts for the important conversion of CO2‐to‐CH3OH.

The Role of Gold-Loaded Copper Oxide Nanoplates in the Formulation of Sensitive EC-SERS Substrates for the Detection of Anti-Cancer Drugs: Spectro–Electro and DFT Studies

The Role of Gold-Loaded Copper Oxide Nanoplates in the Formulation of Sensitive EC-SERS Substrates for the Detection of Anti-Cancer Drugs: Spectro–Electro and DFT Studies

Fabrication of BiCuOS nanoflowers acting as nanoarrays on photonic nanoparticles for chemo-photothermal therapy

In recent years, 3D flower shaped nanostructures with an ability to improve internal photo reflections and absorptions is gaining popularity for the development of photo-thermal heat generating materials for cancer therapy. The use of bimetallic oxysulfide materials as photo-thermal agent is especially interesting as it is not only resulting in heat generation by absorbing laser light in the biological window but also participates in reactive oxygen species generation in tumor environment. In this work, we have reported a novel flower shaped BiCuOS nanostructures made of CuS base structures with vertical nanoarrays of bismuth oxide nanoplates for synergistic chemo-photothermal cancer therapy. Notably, 2D nanoplates (∼150 ± 50 nm in length and thickness of about ∼25 nm) could be seen grown in the form of nanoflowers (NFs) of 800 ± 100 nm in size on CuS base structures. The electronic structure, density of states, bond angle, bond length and thermal stability of formed NFs were investigated by density functional theory and molecular dynamic studies. The photo-thermal conversion efficiency was increased as a function of NF concentration. The percentage of doxorubicin released was estimated to be only ∼4% even after one day of incubation at pH 7.4 which increased to 38 and 45% at pH 5.5 without and with near infra-red light exposure, respectively. The cell viability experiments with fibroblast cells and red blood cells exhibited excellent biocompatibility of BiCuOS NFs. The synthesized BiCuOS NFs showed excellent anticancer activity against Hep-2 cells. Hence, the BiCuOS NFs reported here have huge potential for use as novel dual performing chemo-and-photothermal agent for advanced cancer therapy.

A new shear-thinning nanocomposite hydrogel from GelMA-GO for soft tissue engineering

The use of bio ink materials for fabricating scaffolds is the best option to replace aggressive surgery. This study aims to formulate an injectable hydrogel with suitable structural, mechanical, and rheological properties for tissue engineering applications. In this respect, gelatin methacrylate (GelMA) nanocomposites with different amounts of the modified graphene oxide nanoplates (0.25, 0.5, 0.75, and 1 wt%) were fabricated. The effect of the nanoplates on the structural, degradability, mechanical, rheological, and biological properties of the nanocomposites were evaluated. The results revealed that the functionalization of graphene oxide with dopamine (GOPD) resulted in the formation of a layer of polydopamine on the surface of the nanoplates, which developed the interaction of graphene oxide with GelMA chains. Adding GOPD to GelMA from 0 to 1 wt% decreased the water absorption (0.3 times) and its weight loss percentage (0.2 times). The addition of 0.5 wt% of GOPD to GelMA improved the compressive strength (7.5 times) and compressive modulus (7 times) compared to the GelMA hydrogel. Also, a similar amount of GOPD developed the thin shear properties of GelMA by three logarithmic units. Besides, the addition of the modified graphene oxide nanoplates to GelMA enhanced cell viability (93.26%) after 72 h of cell seeding. The proper behavior of the GelMA hydrogel with 0.5% GOPD, and its stability during the 3D printing process was confirmed. Accordingly, the injectable GelMA hydrogel containing dopamine-modified graphene oxide could be a proper candidate for tissue engineering expenditures.

Enhancing High‐Temperature Energy Density through Al2O3 Nanoplates with Charge Barrier Effect in Polyetherimide‐Based Composites

AbstractPolymer‐based dielectric composites have a wide range of applications in modern electronics and power systems owing to their incomparable reliability, but remain a challenge to energy density at high temperatures. In this work, polyetherimide (PEI)‐based nanocomposites with a small amount of aluminium oxide (Al2O3) nanoplates are prepared and obtain excellent energy density at elevated temperatures. The high‐temperature energy density of the nanocomposites is significantly improved and reaches to 5.2 J cm−3 at 550 kV mm−1 and 150 °C after adding 0.6 wt% Al2O3 nanoplates. The enhanced energy density is attributed to the wide band gap and flaky morphology of Al2O3 nanoplates that can induce charge barrier effect and thus reduce the leakage current density within the nanocomposites. Furthermore, finite element simulations further reveal the mechanism of Al2O3 nanoplates acting as charge barrier to capture the charges transmitted from PEI matrix at the interface. This work offers a promising pathway to high‐energy density polymer dielectrics capable of operating under high temperatures.

Improved catalytic and bactericidal behavior with in silico molecular docking analysis of barium/chitosan doped tungstate oxide nanoplates

In this paper, hydrothermally prepared doping-dependent (barium-Ba and chitosan-CS) properties of WO3 nanocomposite were examined. Various concentrations of Ba (3, 6, and 9 wt.%) were systematically added into the binary system (CS-WO3) nanocomposite. Numerous intrinsic disadvantages of nanoplates as lower surface-to-volume ratio and rapid recombination rate significantly reduced the WO3 activities. To address these issues, Ba/CS was introduced as a dopant; CS encapsulates the WO3, which controls particle size and rapidly overcomes the recombination rate issues, resulting in improved catalytic and antimicrobial activity. The catalytic activity of WO3 and doped WO3 degraded the MB dye by 99.9% in the presence of a reducing agent (NaBH4) in acidic and neutral media. The zone of inhibition was determined (using a Vernier Caliper) against Escherichia coli (E. coli) pathogens at low and high dosages to test antimicrobial activity of synthesized nanostructures. These Ba/CS-doped WO3 nanoparticles have been proposed as putative inhibitors of the DNA gyrase and reeducate of the protein enoyl-acyl carrier (FabI) of E. coli by in silico docking investigation.

Carbon nanosheets coated on zirconium oxide nanoplate nanocomposite for Zn2+ ion adsorption and reuse of spent adsorbent for fingerprint detection

Carbon nanosheets coated on zirconium oxide nanoplate nanocomposite for Zn2+ ion adsorption and reuse of spent adsorbent for fingerprint detection

Interconnected CuO nanoplates as a highly efficient electrocatalyst for oxygen evolution reaction

In this present work, we successfully develop copper oxide (CuO) nanoplates using a facile precipitation process without utilizing any convoluted equipment and high-cost raw materials. The X-ray diffraction (XRD), Raman, and the energy dispersive X-ray (EDX) analysis revealed the formation of pure phase CuO powder. The sample exhibits an interconnected nanoplates-like structure, which facilitates the fast movement of charge carriers throughout the sample. For the sample, a moderate overpotential (492 mV vs SCE) is sufficient to achieve a current density of 10 mA/cm2. It exhibits a low Tafel slope of 69.5 mV dec−1 and achieved long-term stability over 5000 cyclic voltammetry (CV) cycles.

Removal of Cd (II) Ions from Water Solutions Using Dispersive Solid-Phase Extraction Method with 2-aminopyridine/graphene Oxide Nano-Plates

Background: The effluent release containing heavy metals as Cd (II) ions has drastic risks to both the natural environment and human health. In this research, a novel nano sorbent from the pyridine derivative was prepared for dispersive solid-phase extraction of Cd (II) ions. Methods: Graphene oxide (GrO) was chemically modified by a 2-aminopyridine group (2Ap) through a multistep procedure. The affection of adsorbent amount, pH, temperature, equilibrium time on its sorption with Gr2Ap adsorbent was studied and Gr2Ap adsorbent displayed a high ability to adsorb Cd (II) at pH=6. Furthermore, to inquire about the adsorption isotherms of metal ions sorption mechanism, the model of Freundlich and Langmuir was fitted to empirical isotherm data. Besides, to inspect the basic process of the metal sorption mechanism pseudo-first and second-order kinetic, and Roginsky-Zeldovich types were compatible with adsorption kinetic results. Results: The concentration factor and limit of detection for Cd (II) were 12.5 and 1.84 µg/L, respectively. According to the value of the correlation coefficient factor, that the Gr2Ap adsorbent exhibits the highest ability to adsorb Cd (II) ions (22.54 mg/g) at pH=6. The pseudo-second-order pattern of Cd (II) adsorption fits best with the kinetic result. Conclusion: The Gr2Ap exhibited a high potential for removing the heavy metal ions from aqueous samples. Besides, the current research was shown an efficient, easy, inexpensive, and selectable method for evaluating the Cd (II) ions in several samples of water and wastewater.