Oxide Nanoflakes Research Articles

Carbon-doped bimetallic oxide nanoflakes for simultaneous electrochemical analysis of ascorbic acid, uric acid, and acetaminophen in sweat.

Non-invasive continuous detection using tears or sweat as substitutes for blood samples has become an emerging method for real-time monitoring of human health. However, its development is limited by the low sample volume and low level of analytes. The simultaneous determination of multi-analytes with highly sensitive electrochemical sensing platforms has undoubtedly resulted in breakthrough innovations. Furthermore, the determination mode of multi-analyte combinations can accurately characterize the course of certain diseases. In particular, the simultaneous determination of ascorbic acid (AA), uric acid (UA), and acetaminophen (AC) in sweat will provide a one-stop detection system for cardiovascular and degenerative diseases for the entire course analysis. A sacrificial template strategy was adopted in this work using graphene oxide (GO) to guide the growth of two-dimensional Fe-Co composite nanoflakes with large specific surface areas. Defects were introduced via doping carbon through the incomplete pyrolysis of GO. The synthesized C-Fe1.33Co1.67O4 exhibited massive redox sites and was highly reactive, which met the requirements for multi-substance analysis. The electrochemical sensor based on C-Fe1.33Co1.67O4 accurately and sensitively demonstrated simultaneous detection of AA, UA, and AC in sweat, with a wide detection range for AA (4.0-11500 μM) and high sensitivity for UA and AC (304.5 μA mM-1 and 404.1 μA mM-1, respectively), along with low detection limit (1.69 μM for AA, 0.23 μM for UA, and 0.07 μM for AC). The sensor also possessed adequate mechanical flexibility, making it suitable for body surface detection, and its performance was maintained above 80% after high-intensity bending 350 times.

Easy One-Pot Decoration of Graphene Oxide Nanosheets by Green Silver Nanoparticles.

In this study, we developed a facile one-pot synthesis of a nanocomposite consisting of silver nanoparticles (AgNPs) growing over graphene oxide (GO) nanoflakes (AgNPs@GO). The process consists of the in situ formation of AgNPs in the presence of GO nanosheets via the spontaneous decomposition of silver(I) acetylacetonate (Ag(acac)) after dissolution in water. This protocol is compared to an ex situ approach where AgNPs are added to a waterborne GO nanosheet suspension to account for any attractive interaction between preformed nanomaterials. The systems under investigation are characterized by UV/vis absorption spectroscopy, dynamic light scattering (DLS), zeta potential (Z-Pot), and scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDX). The stability of the AgNPs@GO composite suspension is tested as a function of GO concentration (0-67 μg/mL) while maintaining a constant Ag content (14.4 μg/mL), exhibiting excellent stability over time up to an Ag-to-GO mass ratio of 0.58.

Harnessing 3D Porous Cobalt Oxide Nanoflakes Grown on Metal for Exceptional Adhesion between Aluminum Surfaces and the Epoxy Matrix

The developments in the automotive and aerospace sectors require alternative structures to metals for diverse applications; therefore, lightweight polymer–metal hybrid composites with outstanding mechanical characteristics are synthesized. Herein, the modern nanoperfusion technology, which involves the in situ growth of 3D porous cobalt oxide nanoflakes (Co3O4 NFs) on the porous aluminum surface, is used. A rough surface with corresponding surface porosities of 21, 48.1, and 49.8% can be produced by anodization of aluminum at 8, 10, and 12 V, respectively. The samples anodized at 10 V are selected as a structure for the growth of 3D Co3O4 NFs at different hydrothermal temperatures (90, 120, and 160 °C). The bond strength and modulus of the toughness of the sample combining aluminum and 3D Co3O4 NF growth at 120 °C exhibit a substantial bonding strength, reaching a value of 14.27 MPa and 3.56 kJ m−3, respectively. The porous nature of the manufactured cobalt oxide nanoflakes allows the epoxy to penetrate, which enhances the bonding strength and thus improves the mechanical properties of the manufactured joints.

Light-activated nanocomposite thin sheet for high throughput contactless biomolecular delivery into hard-to-transfect cells.

High throughput intracellular delivery of biological macromolecules is crucial for cell engineering, gene expression, therapeutics, diagnostics, and clinical studies; however, most existing techniques are either contact-based or have throughput limitations. Herein, we report a light-activated, contactless, high throughput photoporation method for highly efficient and viable cell transfection of more than a million cells within a minute. We fabricated reduced graphene oxide (rGO) nanoflakes that was mixed with a polydimethylsiloxane (PDMS) nanocomposite thin sheet with an area of 3 cm2 and a thickness of ∼600 μm. Upon infrared (980 nm) nanosecond pulse laser exposure, the rGO nanoflakes induced heat and created photothermal bubbles, leading to cell membrane deformation and biomolecular delivery. Using this platform, we achieved delivery of small to large size molecules, such as propidium iodide (PI) dye (668 Da), dextran (3000 Da), siRNA (20-24 bp), EGFP (6159 bp) and enzymes (465 kDa), in L929, N2a, and HeLa cells as well as in hard-to-transfect NiH3T3 and HuH7 cells. The best results were achieved for enzymes with ∼97% transfection efficiency and 98% cell viability in Huh7 cells. This highly efficient cargo delivery tool is simple and easy to use, and its dimensions can be varied according to the user requirements. Moreover, this safe and successful method has applicability in diagnostics and cell therapy.

Zinc Oxide-Functionalized Hydrophobic Cellulose Nanofiber Aerogel Tailored for Eliminating Conventional Ibuprofen Tablets from Water.

A hydrophobic cellulose aerogel having water contact angle of 149⁰ was fabricated by harnessing the effect of both zinc oxide nanoflakes and stearic acid, and then employed for the elimination of emerging pharma residue Ibuprofen from water. The kinetic experimental data obtained for adsorption process was well suited with pseudo-second order kinetics. The adsorption process was well governed by Langmuir monolayer adsorption and the modified aerogel exhibited a maximum adsorption capacity of 33.52 mg/g. The hydrophobic aerogel exhibited a removal efficiency of 70 % within 60 min of contact time. Moreover, the efficiency of the adsorption process was also analyzed by altering various parameters such as pH, adsorbate dosage and adsorbent concentration. The adsorption efficiency was maximum at pH 2 and at 60 minutes of contact time. The elimination of IBP from water by the hydrophobic cellulose aerogel was assisted by hydrogen bonding, and hydrophobic-hydrophobic interaction occurred between the adsorbent and adsorbate, which was confirmed by the IR spectroscopy and SEM-EDX of the aerogels before and after the IBP adsorption process. The demonstrated work mainly emphasises assessing the practical applicability of the modified aerogel in adsorbing conventional ibuprofen (IBP) tablets directly obtained from the market rather than solely targeting the pharmaceutical ingredient and thereby, this approach could be effectively implemented at the industrial level.

Fabrication of Two-Dimensional Heterostructure Electrodes for Intercalation Batteries Via Cation-Driven Assembly

The cation-driven assembly technique was developed and employed to fabricate two-dimensional (2D) heterostructures of lithium preintercalated bilayered vanadium oxide (δ-LixV2O5·nH2O or LVO) and graphene oxide (GO) nanoflakes. These heterostructures were formed using concentrated lithium chloride solution and annealed under vacuum at 200ºC. The presence of Li+ ions from LiCl enhanced the formation of oxide/carbon heterointerfaces, improving structural and electrochemical stability. Annealing at 200ºC allowed to remove interlayer water excess and partially reduce GO, thus improving electron transport through reduced GO (rGO) nanoflakes. By varying the initial GO concentration, the carbon content in the heterostructures could be adjusted, affecting the electrochemical performance. Scanning transmission electron microscopy (STEM) imaging combined with electron energy-loss spectroscopy (EELS) clearly revealed the formation of LVO/rGO heterointerface with rGO nanoflakes with thicknesses down to the nanometer scale embedded between the nanometer-thick layers of LVO.Electrochemical cycling of the Li+ cation-assembled LVO/rGO heterostructures in Li-ion cells demonstrated enhanced cycling stability and rate performance with increasing rGO content, despite a slight decrease in charge storage capacity. The improved electrochemical stability was attributed to what we have termed the encapsulation effect, which involves the encasing of LVO nanoflakes between the rGO nanoflakes, leading to the suppressed dissolution of LVO in the electrolyte and mitigating the structural distortion of LVO known to be induced by repeated intercalation/deintercalation reactions during electrochemical cycling. Compared to the electrodes prepared by physical mixing of LVO and rGO nanoflakes, the cation assembled LVO/rGO heterostructures showed superior electrochemical stability, highlighting the stabilizing effect of the 2D heterointerface.The versatility of the cation-driven assembly approach was demonstrated by preparing LVO/rGO heterostructures using different assembling cations: Li+, Na+ and K+. The assembling cations influenced the interlayer spacings and structural water content of the resting LVO/rGO heterostructures. STEM/EELS analysis confirmed the formation of a 2D heterointerface between LVO and rGO for all types of the assembling cations used, with the assembling cations trapped in the interlayer regions. Additionally, STEM/EELS identified a V2O3 phase that formed at the LVO/rGO heterointerface and could stabilize the LVO/rGO heterostructures during cycling. Charge storage mechanism analysis indicated that increased interlayer spacings of the BVO phase and the use of assembling cations to define intercalation sites improved ion diffusion and increased capacities during cycling. Li+ and Na+ cation assembled heterostructures exhibited enhanced ion diffusion and charge storage capacities in their respective charge storage systems (Li-ion and Na-ion cells, respectively). Analyses of our results indicate that the choice of cation for heterostructure assembly can modify the final material structure and tailor ion diffusion and charge storage capacity for specific electrochemical systems, offering a versatile approach for utilizing 2D materials in energy storage applications.

Morphological and quality assessments of unary and binary base immersion-fabricated cupric/cuprous oxide nanoflake-coated copper

Mass production practicable fabrication techniques for wide-application-ranged cupric oxide (CuO) or cuprous oxide (Cu2O) nanostructures are crucial in its research-to-technology thrust. Films of CuO/Cu2O were grown onto copper as coating via a 16-day unary or binary immersion to solutions of barium hydroxide (Ba(OH)2) and/or potassium hydroxide (KOH) with varying concentration proportions. Physical inspection and Raman spectroscopy confirms the identity of the grown films to be CuO for all specimens under study except for the copper foil immersed in unary KOH wherein CuO coexists with Cu2O. Scanning electron microscopy and energy dispersive X-ray spectroscopy (SEM-EDX) reveals the nanoflake morphology of the oxide layers with minimal traces of impurities (maximum impurity: 4.17 At.%) and the abundance of oxygen atoms (41.14–55.68 At.%) among the samples. Copper-to-oxygen ratio of the samples ranged from 0.7 to 1.41. Moreover, analysis of variance (ANOVA) reveals the significant differences of the film and flake thicknesses among the specimens under study. The average nanoflake thickness increases as Ba(OH)2 amount is decreased as opposed to KOH up to the binary immersed sample with equal component proportions (maximum average: 71.7 nm), then decreases as KOH concentration is increased in expense of Ba(OH)2 (minimum average: 29.5 nm). The average film thickness is highest for the 75-Ba(OH)2:25-KOH immersed foil and a decreasing trend is apparent as KOH is further increased at the expense of Ba(OH)2. Preliminary assessments may qualify the fabricated oxide nanoflakes on copper for potential applications.

CoOOH nanoflake as supporter of CRISPR-Cas12a system for facilitated imaging of miRNA-21 in cells

The aberrant expression of miRNA-21 in cells is frequently associated with the occurrence and metastasis of tumors. The CRISPR-cas12a system has been developed for in vitro detection of miRNA due to its distinctive signal amplification characteristics. But its intricate composition and challenges in cellular delivery have limited its application in cell imaging. In this study, we designed an electrostatic adsorption-based probe by combining positively charged cobalt hydroxyl oxide (CoOOH) nanoflakes with negatively charged CRISPR-cas12a system which allows for detection and intracellular imaging of miRNA-21. This method involves using ascorbic acid to reduce CoOOH nanoflakes into Co2+, which subsequently releases the active form of CRISPR-Cas12 for detecting miRNA-21. The probe has a linear detection range for miRNA-21 from 0.5 pM-50 pM and 100 pM-20 nM, with a detection limit of 0.32 pM. It also shows good selectivity, accuracy, good reproducibility and biocompatibility for miRNA-21 analysis. In subsequent cell experiments, the probe exhibits low cytotoxicity and remarkable cell imaging capabilities. Therefore, this probe offers an innovative approach for miRNA-21 analysis.

Rod-type handheld hybrid nanogenerator for mechanical energy harvesting and self-powered speed sensing applications

Nanogenerators offer a promising solution for converting mechanical movements into electricity with significant implications for portable electronics. Herein, we propose a novel approach using magnesium (Mg)-doped zinc oxide (ZMO) nanoflakes (NFs) embedded in polydimethylsiloxane (PDMS) composite films, which serve as the negative tribo-layer in a triboelectric/piezoelectric hybrid nanogenerator (HNG) operating in contact-separation mode. The ZMO NFs, with an optimized Mg concentration for a high dielectric constant, are mixed into PDMS, and their concentration is further optimized to achieve the highest electrical output from the HNG. The optimized device generates a voltage, current, and power density of approximately 186 V, 5.23 μA, and 1.56 W/m2, respectively while also exhibiting high stability. The electricity generated by this HNG is successfully utilized to power commercial portable electronics. To further enhance its practicality, six similar HNGs were fabricated and integrated into a 3D printed structure, forming a rod-type handheld HNG (RTH-HNG). The energy-harvesting capability of the RTH-HNG is systematically investigated under applied external forces. Additionally, the speed-sensing ability of the RTH-HNG during hand-shaking motions is assessed, with the system demonstrating an accuracy of up to 94 % when compared to a commercially available infrared sensor. Moreover, the real-time vibrational energy harvesting capability of the RTH-HNG was demonstrated by attaching it to a bicycle. Therefore, the proposed RTH-HNG can function not only as a mechanical energy harvester for powering small portable electronics but also as a self-sufficient speed sensor for various real-time applications.

Bismuth oxide nanoflakes grown on defective microporous carbon endows high-efficient CO2 reduction at ampere level

Carbon dioxide electroreduction is a green technology for artificial carbon sequestration, which is being delayed from industrialization due to the lack of efficient catalysts at high current conditions. Herein, the Bi2O3 nanoflakes were uniformly grown on a defective porous carbon (PC). This self-assembling Bi2O3/PC catalyst was applied to drive CO2 electroreduction at 1.0 A, 1.5 A and 2.0 A while the Faradaic efficiency of formate reaches 91.50 %, 86.30 % and 84.22 %, respectively. Density functional theory calculations revealed the intrinsic defect of carbon is able to give electron to Bi through O bridge, which increased the electron aggregation of Bi and lowered the generation energy barrier of *OCHO intermediate. Additionally, the unique 3D network of staggered Bi2O3 enhances the CO2 adsorption and favors the electron transportation. By integrating all above advantages into a solid electrolyte-type cell, we are able to produce pure formic acid in a rate of 15.48 mmol h−1 at ampere current.

Effect of Enhancement in Surface Area of Sn‐Doped Cobalt Oxide Nanoflakes for Supercapacitor Application

Effect of Enhancement in Surface Area of Sn‐Doped Cobalt Oxide Nanoflakes for Supercapacitor Application

Flexible Multicavity SERS Substrate Based on Ag Nanoparticle-Decorated Aluminum Hydrous Oxide Nanoflake Array for Highly Sensitive In Situ Detection.

Flexible surface-enhanced Raman scattering (SERS) substrates are very promising to meet the needs for real-time and on-field detection in practical applications. However, high-performance flexible SERS substrates often suffer from complexity and high cost in fabrication, limiting their widespread applications. Herein, we developed a facile method to fabricate a flexible multicavity SERS substrate composed of a silver nanoparticle (AgNP)-decorated aluminum hydrous oxide nanoflake array (NFA) grown on a polydimethylsiloxane (PDMS) membrane. Strong plasmon couplings promoted by multiple nanocavities afford high-density hotspots within such a flexible AgNPs@NFA/PDMS film, boosting high SERS sensitivity with an enhancement factor (EF) of ∼1.54 × 109, and a limit of detection (LOD) of ∼7.4 × 10-13 M for rhodamine 6G (R6G) molecules. Furthermore, benefiting from the high sensitivity, high mechanical stability, and transparency of this substrate, in situ SERS detections of trace thiram and crystal violet (CV) molecules on the surface of cherry tomatoes and fish have been realized, with LODs much lower than the maximum allowable limit in food, demonstrating the great potential of such a flexible substrate in food safety monitoring. More importantly, the preparation processes are very simple and environmentally friendly, and the techniques involved are completely compatible with well-established silicon device technologies. Therefore, large-area fabrication with low cost can be readily realized, enabling the extensive applications of SERS sensors in daily life.

Electrochemical and impedance analysis of nickel oxide nanoflakes-based electrodes for efficient chromo supercapacitors

In response to the dynamic advancement of our growing world, there is a tenacious need for sophisticated technologies and continuous refinement of existing knowledge through rigorous scientific endeavors, all with a focus on achieving sustainable development goals for a cleaner and more prosperous future. In this context, this study involves a novel approach to the synthesis of highly porous and stable nickel oxide (NiO) nanoflakes assembled with stacked nanosheet thin films through hydrothermal methods. These films are in-detail examined for their redox-active chromo-supercapacitive properties. The hydrothermal synthesis technique yields thin films with exceptional adhesion to the electrode surface, remarkable chemical stability, and suitable porous structure. These characteristics are strategically employed to facilitate rapid ion intercalation and deintercalation processes, thereby enhancing electrochemical activity. Notably, films deposited for 6-hour reaction times deliver a higher areal capacitance of 140 mF/cm² (and capacity of 70 mC/cm2) at 0.5 mA/cm², which is higher than other electrodes and earlier reports. In-situ, optical investigations further underscore the high coloration efficiency of 44.14 cm²/C, coupled with large optical modulation of 56.5 % and enduring the electrochemical and electrochromic stability. Further research and optimization of NiO-based materials hold significant potential for the development of efficient, smart, and sustainable energy storage solutions in the evolving field of electrochromic supercapacitors to meet the demands of next-generation electronic systems.

Corrosion protective and antibacterial epoxy coating via benzyldisulfide‑sulfur-doped graphene oxide with machine-learning simulation support

This paper presents a novel approach to enhancing corrosion resistance and antibacterial properties of polymer coatings. Using benzyldisulfide (BDS) as a precursor, sulfur-doped graphene oxide (BGO) nanoflakes were fabricated through a hydrothermal method. The sulfur atoms were successfully integrated into the GO structure and its reduction through high-temperature treatment was validated by a number of experiments, including FE-SEM/EDS, FTIR, Raman, and XPS studies. The GO and BGO nanoflakes were then embedded in an epoxy‑silicone matrix. The prepared BGO-incorporated coating exhibited remarkable hydrophobicity and superior performance in electrochemical impedance spectroscopy (EIS) than the GO-containing counterparts. According to the study, the exceptional corrosion protection observed in BGO-incorporated coating can be attributed to the hydrophobic nature and corrosion inhibition properties of the sulfur provided by the S-doped nanosheets. Furthermore, a neural network was applied to EIS data. Results showed that long-term EIS curves could be acceptably predicted using short-term EIS data. Moreover, the presence of BGO nanoparticles increased the generation of reactive oxygen species and significantly improved the coating's antibacterial activity. Overall, this study highlights the potential of BGO in improving coating antibacterial activity and corrosion protection.

Engineered nanoparticles as Selinexor drug delivery systems across the cell membrane and related signaling pathways in cancer cells

In the present work, molecular dynamics simulation is applied to evaluate the drug carrier efficiency of graphene oxide nanoflake (GONF) for loading of Selinexor (SXR) drug as well as the drug delivery by 2D material through the membrane in aqueous solution. In addition, to investigate the adsorption and penetration of drug-nanocarrier complex into the cell membrane, well-tempered metadynamics simulations and steered molecular dynamics (SMD) simulations were performed. Based on the obtained results, it is evident that intermolecular hydrogen bonds (HBs) and π-π interactions play a significant role in expediting the interaction between drug molecules and the graphene oxide (GO) nanosheet, ultimately resulting in the formation of a stable SXR-GO complex. The Lennard-Jones (L-J) energy value for the interaction of SXR with GONF is calculated to be approximately −98.85 kJ/mol. In the SXR-GONF complex system, the dominant interaction between SXR and GONF is attributed to the L-J term, resulting from the formation of a strong π−π interaction between the drug molecules and the substrate surface. Moreover, our simulations show by decreasing the distance of GONF with respect to cell membrane, the interaction energy of GONF-membrane significantly decrease to −1500 kJ/mol resulting in fast diffusion of SXR-GONF complex toward the bilayer surface that is favored opening the way to natural drug nanocapsule.

Synthesis of BiDy composite oxide nanoflakes with good electrochemical properties

Bismuth dysprosium (BiDy) composite oxide nanoflakes with a thickness of about 50 nm were synthesized using a one-step hydrothermal method. Electrodes modified with BiDy composite oxide nanoflakes exhibited a superior electrochemical behavior for detecting l-cysteine using the cyclic voltammetry (CV) method. The impacts of scan rate, electrolyte and concentration of l-cysteine on electrochemical behaviors were investigated. A pair of strong quasi-reversible CV peaks was observed at +0.03 V (cvp1) and −0.69 V (cvp1′) with peak currents of 171.2 and 171.3 μA, respectively, for a BiDy-composite-oxide-nanoflake-modified glassy carbon electrode (GCE) in 0.1 M potassium chloride (KCl) and 2 mM l-cysteine solution. The GCE modified with BiDy composite oxide nanoflakes displayed a broad range of linearity (0.001–2 mM) and a low detection limit (0.29 μM) for l-cysteine. Using a hydrothermal approach as a synthesis technique for nanoflakes, a facile and sensitive electrochemical sensor based on nanoflakes was developed for detecting l-cysteine, making it a promising approach for practical application.

Design of symmetric supercapacitor based on Co3O4/Carboxymethyl cellulose nanoflakes with excellent cyclic stability

An advanced electrode material having fine micro/nano-architecture that provide unique qualities like ultra-high charge storage capabilities, high specific area and efficient pathway for ion insertion will always have superior position in the energy sphere. The prime motive of the present work is to fabricate carboxymethyl cellulose (CMC) encapsulated cobalt oxide nanoflakes as pioneered electrodes for supercapacitors. Utilizing a Faradaic candidate (cobalt oxide), which traps charges abundantly that leads to attracting capacitance (381 F g−1 at a specific current of 1 A g−1) with least charge transfer resistance (0.87 Ω). Make use of CMC as host that supports the composite via providing admirable cyclic life (100 % capacitance retention even after 5000 continuous charge/discharge cycles). Un-interrupted charge delivery that probably attributed to the formation of flaky architecture of cobalt oxide which was encapsulated by carbon matrix. As the end, a symmetric supercapacitor was designed using Co3O4/C nanoflakes as both positive and negative electrode. The fabricated two cell could capable of maintaining its stability of 95.87 % from its initial value after 5000 cycles of charge and discharge at a practical current density of 20 A g−1. The outcomes of the present study (three and two cell configuration as well) will open new gateways in energy regime for next generation supercapacitors.

Multifunctional Nanocomposite Yield-Stress Fluids for Printable and Stretchable Electronics.

Compliant materials are crucial for stretchable electronics. Stretchable solids and gels have limitations in deformability and durability, whereas active liquids struggle to create complex devices. This study presents multifunctional yield-stress fluids as printable ink materials to construct stretchable electronic devices. Ionic nanocomposites comprise silica nanoparticles and ion liquids, while electrical nanocomposites use the natural oxidation of liquid metals to produce gallium oxide nanoflake additives. These nanocomposite inks can be printed on an elastomer substrate and stay in a solid state for easy encapsulation. However, their transition into a liquid state during stretching allows ultrahigh deformability up to the fracture strain of the elastomer. The ionic inks produce strain sensors with high stretchability and temperature sensors with high sensitivity of 7% °C-1. Smart gloves are further created by integrating these sensors with printed electrical interconnects, demonstrating bimodal detection of temperatures and hand gestures. The nanocomposite yield-stress fluids combine the desirable qualities of solids and liquids for stretchable devices and systems.

Superior antibacterial performance of surfactant-assisted ZnO nanoflakes produced via Co-precipitation method

Microbiological infections are one of the major problems that modern people encounter. Zinc oxide (ZnO) nanoflakes are excellent antimicrobial agents. The objective of this work was to synthesize ZnO nanoflakes with the assistance of surfactants and investigate the processes behind their antibacterial properties. The experiment involved the synthesis of ZnO using several surfactants, including cetyl trimethyl ammonium bromide (CTAB), polyvinyl pyrrolidone (PVP), and polyethylene glycol (PEG), and its analysis using XRD, FT-IR, SEM, EDAX, and BET methods. Both Gram-positive and Gram-negative bacterial strains were used in these investigations. ZnO nanoflakes aided by CTAB (R-2) had the most promising action against the tested bacterial strains like Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and Bacillus cereus. These ZnO nanoflakes with CTAB assistance consistently had greater inhibitory zones than other samples. The R-2 sample’s enhanced surface area and particle size, which result in improved antibacterial activity. The investigation’s outcomes show that the produced nanoflakes have the potential to be useful in antibacterial and other medicinal applications.

Bio-extract mediated green synthesis of bi-functional ammonium cobalt phosphate nanoflakes electrode/catalyst for supercapattery and ethanol oxidation

The present study proposes a low-cost, green technique to the synthesis of bi-functional ammonium cobalt phosphate for energy storage and conversion applications. The comprehensive physiochemical investigations are carried out using various spectral-analytical techniques. The results of phase and surface morphology confirm the formation of an orthorhombic crystal structure with flakes-like microstructure. With a maximal specific capacity of 448.3 mAhg−1 at 2 mAcm−2, bio-solvent driven NH4CoPO4·H2O with graphene oxide (GO) nanoflakes demonstrates exceptional battery-type energy storage capabilities. As constructed supercapattery device exhibits a high specific energy of 85.4 Wh kg−1 at power output of 1283 W kg−1 and 81 % stability after 5000 cycles. Further exploration as a non-precious metal-based catalyst for ethanol oxidation reaction (EOR), NH4CoPO4·H2O /GO showed a high peak current density of 83.4 mAcm−2 at 20 mVs−1. Coupled oxygen/hydrogen evolution processes are investigated in 1 M KOH in order to acquire a better understanding of the catalyst's EOR activity. The NH4CoPO4·H2O/GO sample exhibited the lowest overpotentials of |ηOER@10| = 420 mV, and |ηHER@10| = 112 mV, with Tafel slopes of 169.8 mV dec−1 for OER and 132.8 mV dec-1 for HER, respectively. This is due to the catalyst's slow OH adsorption during OER and the limited H*recombination during HER. Therefore, this approach provides a green and cost-effective method to synthesis efficient bi-functional electrode/catalysts for supercapattery and alkaline fuel cells.