Nanosphere Materials Research Articles

High Performance‐Low Cost‐Chemiresitive BaTiO3 Nanospheres Based CO2 Gas Sensor for Air Quality Monitoring

AbstractSpherical shaped Barium titanate (BaTiO3) nanospheres was synthesized, using co‐precipitate technique. The as‐synthesized nanospheres was discovered to be discriminatory in terms of sensing carbon dioxide (CO2) gas. The structural parameters like, shape, optical properties, morphology, and thermal stability were explored using XRD, FT‐IR, UV‐Visible, EDS and FE‐SEM. Spherical shaped BaTiO3 nanospheres material have the highest response (63 %) for CO2 gas. CO2 gas reaction and recovery times were 23.5 and 20.3 seconds, respectively. The CO2 gas concentration climbs from 1 to 50 ppm, reaction to gas sensors increases. CO2 gas has higher selectivity for BaTiO3 nanospheres as compared to other gases like carbon dioxide (CO2), methane (CH4), carbon monoxide (CO), nitric oxide (NO), hydrogen sulphide (H2S) and hydrogen (H2). The repeatability of BaTiO3 nanospheres was researched for 42 days and discovered to be impressive.

Nanomaterial-based magnetic surface molecularly imprinted polymers for specific extraction and efficient recognition of dibutyl phthalate.

A rapid and selective sorbent for the enrichment of dibutyl phthalate (DBP) from water and Chinese Baijiu samples was established using magnetic surface molecularly imprinted polymers (MSMIPs) combined with gas chromatography-mass spectrometer (GC-MS). The MSMIPs were synthesized using a magnetic nanosphere material with silica layer, increasing the polymer surface area as a carrier. Compared with the traditional methods, the addition of magnetic microspheres simplified the process of food substrate purification and significantly shortened the pre-concentration time. The MSMIPs adsorption conforms to the Freundlich isotherm model as multilayer adsorption on an inhomogeneous surface and the pseudo-second-order model. The developed MSMIPs combined with GC-MS method showed good linearity in DBP concentration range of 0.02-1.0mg L-1 with low LOD (0.0054mg L-1) and LOQ (0.018mg L-1), and obtained good recoveries in real samples (95.2-97.2%) with RSD<5.0% (n=9), which were consistent with those from Chinese national standard method.

Construction of Ru single-atom catalyst with abundant Ru-N active domains for highly efficient acetylene hydrochlorination

Single-atom catalysts (SACs) have sparked gigantic attention due to their high activity, atomic utilization, and unique metal–host coordination environment. A hard-template method with Lewis acid modification strategy was adopted to obtain mesoporous N-doped carbon nanospheres as the host to prepare a Ru SAC for acetylene hydrochlorination. The single site scattered Ru-N-C active structure constructed by the interaction between the metal–support and the heteroatom-rich mesoporous g-NC nanosphere material provides a rich defect structure that promotes the mass transfer of reactants and products. Furthermore, the N-doped support anchors, disperses and modulates the catalytic active domains, stabilizing their active state and enhancing the adsorption and activation of initial reactants. As a result, the obtained Ru SAC possesses excellent catalytic properties and lasting life in a 500-h test, which render it highly promising for industrial applications. Moreover, the clarified catalytic mechanism provides a reference for the preparation of other SACs.

A Fe2(SO4)3-assisted approach towards green synthesis of cuttlefish ink–derived carbon nanospheres for high-performance supercapacitors

The conversion of renewable biomass resources into advanced electrode materials through green, simple, and economical methods has become an important research direction in energy storage. In this study, Fe-decorated N/S-codoped porous carbon nanospheres have been successfully fabricated from cuttlefish ink through Fe2(SO4)3-assisted hydrothermal carbonization coupled with heat treatment. The effects of Fe2(SO4)3 dosage on the structure, chemical composition, and capacitive property of carbon nanospheres were investigated. Herein, environmentally friendly Fe2(SO4)3 plays a multifunctional role as the graphitization catalyst, dopant, and morphology-regulating agent. Benefitting from the moderate graphitization degree, great heteroatom content and hierarchical porous structure, the prepared carbon nanospheres exhibit high specific capacitance (311.9 F g−1 at a current density of 0.5 A g−1), good rate capability (19.1% decrease in specific capacitance as current density increases from 0.5 to 10 A g−1), and ideal cycling stability (94.3% capacitance retention after 5000 cycles). In addition, the symmetric supercapacitor assembled with the carbon nanosphere electrodes achieves an energy density of 9.7 Wh kg−1 at a power density of 0.25 kW kg−1 and maintains 91.3% capacitance after 10,000 cycles. The desirable electrochemical performance of cuttlefish ink–derived carbon nanosphere material makes it a potential electrode candidate for supercapacitors.

An intelligent alkyne-tag for Raman imaging of living cells: graphdiyne-encapsulated Au nanospheres.

A new graphdiyne-encapsulated Au nanosphere (Au@GDY) material was fabricated, which possessed an amplified Raman signal of acetylene linkage and produced bright, stable, and distinct signals in the cellular Raman-silent region. Its signal repeatability is far superior to that of alkyne-containing molecules. This work provides promise as an alkyne-tag for Raman imaging of living cells.

Inverse spinel cobalt manganese oxide nanosphere materials as an electrode for high-performance asymmetric supercapacitor

In energy storage devices, it is critical to further develop spinel structured functional materials with rich redox-active sites and high theoretical capacitance. In this study, the nanosphere-shaped Cobalt Manganese Oxide inverse spinel structure was prepared by polyvinylpyrrolidone-assisted hydrothermal technique followed by calcination at 300 °C. Benefitting from the small nanosphere architecture, the Cobalt Manganese Oxide exhibits a high specific surface area to offer more redox-active sites and has a highly porous nature to shorten the ion movement pathway. The obtained Cobalt Manganese Oxide nanospheres exhibit a battery-like energy storage mechanism with a specific capacity (580 C g−1 at 5 mV s−1), high rate capability, and long-term cyclic stability performance (91.2% at 100 mV s−1 for 5000 cycles) in 6 M KOH electrolyte. The fabricated asymmetric supercapacitor device displays a high energy density of 29.1 Wh kg−1 at a power density of 320 W kg−1, and a power density of 3840 W kg−1 at an energy density of 4.4 Wh kg−1 with cyclic stability of 96.5% after 10,000 galvanostatic charge/discharge (GCD) cycles. The electronic structural properties explain density functional theory (DFT).

Construction of Ag: ZnIn2S4/Bi2S3 Z-scheme heterojunctions for boosting interfacial charge separation and photocatalytic degradation of TC

The construction of Z-scheme heterostructures is one of the most effective strategies to improve photocatalytic efficiency. In this study, Ag+ doped ZnIn2S4/Bi2S3 composite nanosphere materials with different mass fractions of Bi2S3 were successfully synthesized by the solvothermal method. Systematic studies showed that the construction of heterogeneous structures and Ag+ doping could extend the optical absorption edge and provide more active sites. More importantly, it was shown by photoelectrochemical and PL spectroscopy tests that Ag: ZnIn2S4/Bi2S3 has strong visible light absorption and photocarrier transfer capability. In addition, the Z-scheme mechanism of Ag: ZnIn2S4/Bi2S3 was investigated by electron spin response (ESR) and active substance capture experiments, which confirmed that both superoxide radicals(O−2) and hydroxyl radicals(OH) were involved in the photocatalytic reaction. The results showed that the optimized Ag: ZnIn2S4/2.5%Bi2S3 degraded TC by 89.7%, 1.87 times higher than the original ZnIn2S4. This work provides a promising method for the construction of Z-scheme heterojunctions based on ZnIn2S4.

Double recovery and regeneration of Pt/C catalysts: Both platinum from the spent proton exchange membrane fuel cell stacks and carbon from the pomelo peel

A novel double-recycling engineering for the regeneration of Pt/C graphitized hollow nanosphere catalysts was proposed for the first time. After recycling Pt from waste proton exchange membrane fuel cell stacks (PEMFC) as a platinum source and recycling waste pomelo peel as a carbon source, Pt/C catalysts were regenerated by polyol reduction, which was useful for sustainable energy development. The recovery efficiency of Pt reaches 96.4 ± 0.2%. The graphitized hollow nanospheres were synthesized by investigating critical factors by adjusting: 1) pyrolysis temperature and 2) treatment method. The graphitized hollow nanosphere material from the waste pomelo peel was prepared by an improved method at 1000 °C (denoted as PP-2–1000). The recovered Pt was combined with PP-2–1000 and commercial carbon (CC) to make Pt/PP-2–1000 and Pt/CC catalysts, respectively. The electrochemical active surface area (ECSA) of Pt/PP-2–1000 is equivalent to that of Pt/CC. For oxygen-reduction reaction (ORR), the mass activity (im at 0.9 V) of Pt/PP-2–1000 is 2.98 times higher than that of Pt/CC. After the accelerated durability test (ADT), the ECSA's remaining efficiency of Pt/PP-2–1000 is 10.1% higher than that of Pt/CC. It proves that the recovered Pt/PP-2–1000 has excellent stability and electrochemical performance. The research may have a profound impact on the sustainable development of PEMFC and biomass-related industries.

Synthesis of multifunctional crown ether covalent organic nanospheres as stationary phase for capillary electrochromatography

Crown ethers are macrocyclic polyether compounds containing multiple -oxo-methylene-structural units, which are often used for recognition of metal ions and ammonium ions. Inspired by the molecular design of rotaxanes, a novel covalent organic nanospheres material (CON ADBC-Tp) constructed by 4,4′-diaminodibenzo-18-crown-6 (ADBC) and 2,4,6-triformylphloroglucinol (Tp) was rationally designed as stationary phase for the separation of compounds containing imidazole structure. Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR) were carried out to confirm the morphology and composition of ADBC-Tp and ADBC-Tp modified capillary column. Thanks to the introduction of crown ether building ligands, the prepared capillary column exhibited excellent separation selectivity towards protonated imidazole structure, with benzimidazole and its 2-substituted derivatives as modal analytes. Moreover, separation of fungicides, nucleobases, short peptides and sulfanilamides were achieved on ADBC-Tp@capillary. The multifunctional ADBC-Tp@capillary with satisfactory reproducibility and stability gives great promise for separation science.

Screening of Phospholipids in Plasma of Large-Artery Atherosclerotic and Cardioembolic Stroke Patients With Hydrophilic Interaction Chromatography-Mass Spectrometry.

Ischemic stroke (IS) is a deadly and debilitating disease with a high incidence and recurrence rate in elderly people worldwide. Large-artery atherosclerotic (LAA) and cardioembolic (CE) stroke are two leading subtypes and require different management. As a complementary biochemistry method for current diagnostic techniques, a sensitive and accurate phospholipid (PL) targeted lipidomic method was developed in this study. Plasma PLs were selectively extracted with titanium dioxide/fibrous silica nanosphere material, then characterized and quantified with hydrophilic interaction chromatography-mass spectrometry. A total of 31 molecular species of PLs were determined and ten biomarkers including seven molecular species of sphingomyelins (SM d18:1/18:1, d18:1/18:0, d18:1/24:1, d18:1/16:1, d18:1/22:1, d18:1/24:2, and d18:1/16:0) and three molecular species of phosphatidylcholines (16:0/18:1, 16:0/18:2 and 16:0/22:6) showed significant differences in LAA, CE, and healthy control (HC) groups. The independent diagnostic capabilities of these PL biomarkers were successfully evaluated and validated with receiver operating characteristic curves. Additionally, the oleic acid-enriched SMs, which can result in atherogenic lipoprotein aggregation, were proved to be positively related to IS and may perform as the potential risk factors in the future. Meanwhile, valuable suggestions for dietary interventions as an essential source of endogenous PLs could be obtained from this study.

Pyromellitic diamide-diacid bridged mesoporous organosilica nanospheres with controllable morphologies: a novel PMO for the facile and expeditious synthesis of imidazole derivatives.

In this work, novel pyromellitic diamide–diacid bridged mesoporous organosilica (PMAMOS) nanospheres with controllable morphologies and Brønsted acid catalytic centers were designed and prepared through a convenient method by altering the addition sequence of precursors, solvent, and aging time. The obtained PMAMOSs demonstrate high surface areas and uniform pore sizes. FESEM, HRTEM, BET, EDX, XRD, FTIR and TGA analyses were performed to characterize and examine the effective factors for the preparation of PMAMOS nanospheres. Due to the appropriate physicochemical properties including Brønsted acid centers, suitable surface area and thermal stability of the PMAMOS nanosphere material, it was explored in the three-component reaction of benzyl or benzoin, ammonium acetate, and different aldehyde derivatives as a case study of multicomponent reactions. Corresponding imidazole derivatives were obtained in EtOH under reflux conditions in high to quantitative yields and short reaction times. It was also shown that the heterogeneous solid acid can be reused at least five times with negligible loss of its catalytic activity, indicating the appropriate stability and high activity of the newly introduced mesoporous organosilica.

Template-free single-step preparation of hollow CoO nanospheres using pulsed laser ablation in liquid enviroment

Owing to their unique properties, hollow nanoparticles have attracted tremendous attention in various research fields. However, it is a still challenge to prepare hollow nanoparticles without hard or soft template. In this study, high purity cobalt oxide (CoO) hollow nanosphere was experimentally obtained using pulsed laser ablation (PLA) in ethanol–water mixture. The morphological and optical properties of the fabricated nanospheres were investigated via different analytical techniques, including scanning electron microscopy, transmission electron microscopy, Fourier transform infrared, and ultraviolet–visible spectroscopy. Selected area electron diffraction, and energy-dispersive X-ray spectroscopy were utilized to evaluate the crystalline structure as well as the chemical composition of the fabricated materials, respectively, The ethanol/water mixture was varied during the ablation process from 0 to 70 % v/v and found to have a significant impact on the size, shape, and structure of the produced nanoparticles. The average size was found to be about 100 nm for the 0–30% v/v of ethanol and around 200 nm for the 50 and 70% v/v of ethanol. It was also shown that the optimum ratio of ethanol–water mixture for the formation of hollow nanoparticles is between 5 and 30% v/v as the formation the hollow structures is directly associated with the saturation of the gas in the medium. A possible mechanism for the formation of hollow structure CoO using pulsed laser ablation in ethanol/mixture media is discussed. This study paves the way for fabrication of template-free hollow nanosphere materials for several applications.

Improved tin oxide nanosphere material via co-precipitation method as an anode for energy storage application in Li-ion batteries

The present proposed work, a design and fabrication of tin oxide nanosphere (SnO2) using tin(II) oxyhydroxide and terephthalic acid composite materials, for the first time, via co-precipitation method. The morphology of the materials is found to be a well-crystalline nature and agglomerated with nanospherical shapes; it exhibits a 20–30-nm particle size. The electrochemical discharge–charge studies have been done using a half-cell (2032-sized coin type) at current rate 100 mA g−1 and within the potential range of 0.01 and 2.0 V vs. Li/Li+. The impedance spectroscopy (EIS) and cyclic voltammetry (CV) studies are showing high resistance and a good oxidation–reduction properties. The cycle number vs. capacities illustrates the initial discharge capacity of 1149 mAh g−1 and the charge capacity retention from the second cycle (91%), respectively; it have been maintained up to the end of cycling. Thus, the prepared electrode can be developed for reversibility properties and possibly used as an anode for Li-ion batteries.

Sodium‐Ion Batteries: Ostwald Ripening Tailoring Hierarchically Porous Na3V2(PO4)2O2F Hollow Nanospheres for Superior High‐Rate and Ultrastable Sodium Ion Storage (Small 48/2020)

In article number 2004925, Yan Yu, Yanglong Hou, and co-workers report a hierarchical porous Na3V2(PO4)2O2F hollow nanosphere material with fast ionic/electronic conductivities, easy and continuous electrolyte supplement and robust electrode integrity properties, kinetically accelerated sodium-ion storage behavior of high-capacity, high-rate and long-life cycling.

Solvothermal synthesis of Fe3O4 nanospheres for high-performance electrochemical non-enzymatic glucose sensor

Ferroferric oxide (Fe3O4) nanospheres have been synthesized via a facile solvothermal procedure to serve as an electrode material for high performance non-enzymatic glucose sensor. The as-synthesized Fe3O4 nanospheres with a uniform size from 16 to 18 nm, which can increase the reaction contact area and the active sites in the process of glucose detection. Benefiting from the particular nanoscale structure, the Fe3O4 nanospheres obviously enhanced the activity of electrocatalytic oxidation towards glucose. When the Fe3O4 nanospheres material was used for non-enzymatic glucose sensor, several electrochemical properties including the high sensitivity 6560 μA mM−1 cm−2 (0.1–1.1 mM), limit of detection 33 μM (S/N = 3) and good long-term stability were well demonstrated. Furthermore, Fe3O4 nanospheres electrode confirmed the excellent performance of selectivity in glucose detection with the interfering substances existed such as urea, citric acid, ascorbic acid, and NaCl. Due to the excellent electrocatalytic activity in alkaline solution, the Fe3O4 nanospheres material can be considered as a promising candidate in blood glucose monitoring.

Fabrication of ascorbic sensor acid with Co3O4.Fe2O3 nanosphere materials by electrochemical technique

In this study, the Co3O4.Fe2O3 nanospheres (NSs) was prepared by hydrothermal process in high alkaline environment of pH 10.5. X-ray photoelectron spectroscopy (XPS), field Emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDS) and X-ray diffraction analysis were performed to characterize the prepared Co3O4.Fe2O3 NSs. The Co3O4.Fe2O3 NSs was subjected to deposit onto a glassy carbon electrode (GCE) of 0.0316 cm2 surface area with nafion (5% suspension in ethanol) adhesive as thin film to obtain the desire ascorbic acid (AA) sensor. The calibration curve of AA sensor was plotted as current versus concentration of AA, which is a linear from 0.1 nM to 0.01 mM on calibration curve defined as linear dynamic range (LDR). The slope of LDR is used to calculate the sensitivity of sensor by considering the active surface area of electrode and is equal to 15.4367 µAµM−1cm−2. The limit of detection (LOD; 96.02 ± 4.80 pM) and the limit of quantification (LOQ; 320.07 ± 10.0 pM) of AA sensor are calculated. The reproducibility, response time and long-time stability of sensor are exhibited as outstanding. The electrochemical analyzing of real samples, the AA sensor is shown its reliability.

Neurotoxic effect of non-functionalized carbon nanospheres

Objective. Different types of nanoparticles, including carbon ones, were tested for a variety of biological applications. Alongside with promising results, some undesired side effects were disclosed. Most biological studies were performed on highly functionalized carbon nanospheres, so the main objective of this study was to assess cytotoxicity of unfunctionalized carbon nanospheres synthetized by sol-gel method. We hypothesize that unfunctionalized material will present different cytotoxic pattern on cell culture. Methodology. 3 carbon nanosphere materials were synthetized by sol-gel method. Particles shape, size and functionalization were assessed. Cytotoxic effect of synthesized materials was evaluated on SH-SY5Y cell line using XTT and crystal violet assays and imaging. Contribution. In this work we have demonstrated that cytotoxic effect of carbon nanospheres can be attenuated by varying the conditions of synthesis.

Strong pyro-catalysis of shape-controllable bismuth oxychloride nanomaterial for wastewater remediation

In this work, the shape-controllable bismuth oxychloride nanomaterials were hydrothermally synthesized for pyro-catalysis treatment of dye wastewater. Under the 25–65 °C cold-hot excitation, the bismuth oxychloride nanoplates, nanoflowers and nanospheres with different specific surface areas of 5.9813, 6.2281 and 12.9614 m2/g, can respectively decompose 12.20%, 58.80% and 85.31% dye solution. The radicals’ trapping experiment confirms that superoxide radicals, hydroxyl radicals and holes are the major active species in this pyro-catalysis process. The bismuth oxychloride nanosphere material with the excellent pyro-catalysis performance is potential for dye decomposition and wastewater remediation through utilizing thermal energy from temperature fluctuation.

Silica Supported MgO as An Adsorbent for Precombustion CO2 Capture

MgO-silica nanocomposites were synthesized by dispersing MgO on three different silica supports, viz., ordered mesoporous MCM-41, SBA-15, and the nonporous fibrous silica nanospheres material (KCC-...

Synthesis of Carbon Nanosphere at Low Temperatures Based on Bamboo Fiber

Carbon Nanosphere (CNs) has been successfully synthesized from bamboo fibers at low temperatures by carbonization and activation. For activation used Potassium Hydroxide (KOH) at temperature 105°C, 155°C, 205°C, 255°C and 305°C. X-Ray Diffraction (XRD) spectra shows hexagonal and amorphous phase and Fourier Transform Infrared (FTIR) spectra shows decrease C-O bond with increasing activation temperature. Transmission Electron Microscopy (TEM) image for activation temperature of 105°C confirmed that sources the formation of Carbon Nanosphere. In this study shows bamboo fiber has a high potential as a carbon nanosphere material.