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Apart from perovskites, the development of different types of pyrochlore oxides is highly focused on various electrochemical applications in recent times. Based on this, we have synthesized pyrochlore-type praseodymium stannate nanoparticles (Pr2Sn2O7 NPs) by using a coprecipitation method and further investigated by different analytical and spectroscopic techniques such as X-ray diffraction, Raman spectroscopy, field emission-scanning electron microscopy, high resolution-transmission electron microscopy, and X-ray photoelectron spectroscopy analysis. Followed by this, we have designed a unique and novel electrochemical sensor for nitrofurazone detection, by modifying the glassy carbon electrode (GCE) with the prepared Pr2Sn2O7 NPs. For that, the electrochemical experiments were performed by using cyclic voltammetry and differential pulse voltammetry techniques. The Pr2Sn2O7 NPs modified GCE exhibits high sensitivity (2.11 μA μM−1 cm−2 ), selectivity, dynamic linear ranges (0.01−24 μM and 32−332 μM), and lower detection limit (4 nM). Furthermore, the Pr2Sn2O7 NPs demonstrated promising real sample analysis with good recovery results in biological samples (human urine and blood serum) which showed better results than the noble metal catalysts. Based on these results, the present work gives clear evidence that the pyrochlore oxides are highly suitable electrode materials for performing outstanding catalytic activity toward electrochemical sensors.

A potentially significant limitation of typical short structure in de-embedding launch line inductance with ground-signal-ground (GSG) padsets is revealed in this paper. It is shown that the calculated inductance (L) value with conventional open-short-pad (OSP) de-embedding is significantly higher than the actual value. With the help of electro-magnetic (EM) simulations, the mechanism behind this inaccurate short de-embedding for L calculation is demonstrated. A simple alternative short structure is proposed to alleviate this issue. The proposed structure is extensively validated using well calibrated EM simulations across inductor geometries. Finally, measured result of spiral inductor with GSG padsets validate the merit of the proposed approach.

Recent progress in quantum nanophotonics brings novel ways for manipulating single photons in various nano-waveguides. Among them, one promising approach is to use optical nanofibres (ONFs), tapered optical fibres with sub-wavelength diameter waists. Here, we develop a hybrid system of an ONF and a single quantum dot (QD) operated at cryogenic temperatures. We deposit a single colloidal CdSe QD on an ONF waist and observe emitted photons through the fibre guided modes. We systematically investigate emission characteristics for both the neutral exciton and charged exciton (trion) for one specific QD. We quantitatively show that the trion at cryogenic temperatures acts as an excellent quantum emitter for the ONF and QD hybrid system. The present ONF/QD hybrid system at cryogenic temperatures paves the way for quantum information technologies for manipulating single photons in fibre networks.

Wireless RF sensors are the building blocks of the next generation sensing techniques that are quite essential for the Internet of Things. In this paper, the RF system comprising of ultra-wideband transmitter-receiver antenna and highly sensitive planar sensor is proposed for wireless sensing of glucose and saline concentration, which are currently being used in various biomedical applications. The proposed wireless sensor technique is quite cost-effective having both antennae and the sensor fabricated on economical FR4 substrate, where the ultra-wide band antennas are operational in 1–18 GHz with highest gain of 7 dBi. The wireless sensor of the proposed RF system possessing high sensitivity of 60 MHz per unit change in dielectric constant of liquid sample are operating over broad frequency range of 1.5 to 5.9 GHz. The sensors are designed, fabricated, and tested for characterizing various biomedically relevant samples: saline and glucose solutions at various concentrations. Our results show that the proposed wireless sensing system possesses strong potential for biomedical applications.

The rapid growth of energy demand and lack of sustainable energy conversion/storage devices have made the supercapacitor an inevitable substitute to current storage systems. However, the major limitation to the cutting edge lies in superconductors’ relatively low energy density compared to batteries. Here, we report LaMnO3/RGO/PANI ternary composite fabricated via in situ polymerization route as an efficient electrode material with enhanced energy density. The all-solid-state designs of both LaMnO3/RGO/PANI∥LaMnO3/RGO/PANI symmetric supercapacitor and LaMnO3/RGO/PANI∥RGO asymmetric supercapacitor have been highlighted in this work. The asymmetric supercapacitor device exhibits a superior electrochemical performance (Sc = 111 F g–1 at 2.5 A g–1 and >50% retention at 20 A g–1) than a symmetric supercapacitor device although both of these devices have an appreciable electrochemical behavior. The asymmetric supercapacitor device delivers a maximum energy density of 50 Wh kg–1 at a power density of 2.25 kW kg–...

LaMnO3 perovskite oxide has got tremendous attraction in electrochemical field owing to their favourable physical and chemical properties. However, aggregated and distorted morphology of regular perovskites that are prepared at higher temperatures (>500 °C) led to lesser active sites provided to enable the electrochemical reaction. Here we propose a green synthetic approach to overcome these deficiencies and to obtain better electrochemical performance. 3D polyhedron structured LaMnO3 nanoparticles are synthesized using natural lemon juice (LJ) as a green surfactant. The aggregation of these particles is removed and a well separated individual particle has been formed. This well defined polyhedron structured LMO nanoparticle possessed a 3 fold enhancement in its specific capacitance. A symmetric two electrode cell system has also been fabricated to investigate the real life application of LMO as a supercapacitor. The electrode in this symmetric cell configuration could deliver a maximum energy density of 52.5 Wh kg−1 at a power density of 1000 W kg−1. This is an outstanding result among aqueous electrolyte symmetric supercapacitors. Moreover, the room temperature fluctuation effect on the specific capacitance of LMO cell has also been investigated. This LJ assisted synthesize of LMO perovskite presented here enlighten a simple paradigm for fabricating high energy electrochemical storage devices.

Electrochemical capacitors have achieved prodigious attention among energy storage devices due to their simple and efficient storage mechanism, moderate specific energy and power densities which bridge the gap between Li-ion batteries and conventional capacitors. The active material plays a foremost role in the energy storage mechanism of such storage devices. Here, we have developed a porous Nickel oxide (NiO) nest-like particle with a large surface area and used as cathode material for supercapacitor application. The porous NiO electrode exhibits an excellent electrochemical performance with a specific capacity of 422 C g−1 at 1 A g−1 specific current. Moreover, the NiO//AC asymmetric device exhibited higher specific energy of 25 Wh kg−1 at a specific power of 1280 W kg−1 and could maintain more than 50% of specific energy at an extra-high specific power of 19.2 kW kg−1. Surprisingly, the device exhibits an ultra-fast power delivery performance with a considerably lower response time (13 ms). The porous NiO nanonetwork-based electrode manifests a great potential to be an ultra-fast efficient next-generation electrode candidate for electrochemical energy storage devices.

Furaltadone (FT) is an antibiotic veterinary drug belonging to the nitrofuran group. FT and its metabolite have carcinogenic and mutagenic behavior, and the excreted metabolite of FT has contaminated the environment. Therefore, the determination of FT in the environment is essential. In view of this, we constructed a low-cost electrochemical sensor for the determination of FT based on cobalt tin oxide/tin oxide (Co2SnO4/SnO2, CTO/TO) nanoparticles. The one-pot synthesis of CTO/TO nanoparticles was prepared by a simple co-precipitation method and characterized by various analytical techniques such as PXRD, FT -IR, FE-SEM combined with EDX, HR-TEM and XPS. Subsequently, electrochemical techniques such as EIS, CV and DPV were performed for the detection and determination of FT using CTO/TO nanoparticles modified SPCE. Under optimal conditions, the designed sensor showed good sensitivity (0.66 µA µM-1 cm-2), wider linear ranges (0.1–73 µM and 91–1022 µM) and lower detection limit of 39 nM. The designed FT sensor has been successfully applied to real sample analysis in water samples and the recovery results obtained are very satisfactory. Based on these results, we believe that the as-prepared CTO/TO will be a potential material for FT sensors in environmental applications.

Molybdenum disulphide (MoS2) is widely explored in the area of electrochemical energy storage devices as an alternative to graphene. Here we introduce a 1T-MoS2 electrode with defect induced active edges for high performance supercapacitors. The metallic phase (1T) facilitates enhanced electrical conductivity and defect rich morphology that results in a high specific capacitance value. The structural characterisation confirms the formation of 1T phase and defect concentration in the material. Transmission electron microscopy imaging further confirms the presence of defects in high defect density MoS2 (HDD-MoS2) and low defect density MoS2 (LDD-MoS2). The electrochemical studies show that the prepared high defect density MoS2 electrode exhibits a maximum specific capacitance of 379 F g−1 and 68.9 F g−1 at 1 A g−1 current density in three and two electrode systems, respectively. The symmetric HDD-MoS2 supercapacitor exhibits an outstanding cell performance with an energy density of 21.3 W h kg−1, at a power density of 750 W kg−1 and a capacitance retention of 92% after 3000 cycles. These findings suggest that 1T MoS2 with high defect density can be a potential candidate for high performance supercapacitor electrode application.

In this paper, the improved planar resonant sensors based on the generalized split ring resonator (SRR) configuration are proposed for the permittivity and the permeability testing of magneto-dielectric samples. It is observed that the proposed inter-digital capacitor-based SRR and the meandered line-based SRR provide better sensitivity for dielectric and magnetic measurement, respectively, when compared with the standard SRR-based microwave sensors. Both the sensors are first modeled under unloaded condition, using the full wave electromagnetic solver, the CST Microwave Studio, in order to ensure their operating frequency range near 2.45 GHz of industrial, scientific and medical band. In the next step, the numerical simulation of these sensors is carried out by loading them with a number of reference materials in order to develop empirical model for the determination of permittivity and permeability of test samples. Additionally, the equivalent circuit models of these sensors are obtained using the Advanced Design System circuit simulator and results are compared with the numerical simulation. All the sensors are designed and fabricated on 1.27-mm-thick RT/Duroid 6006 substrate, and testing is carried out using the network analyzer. A number of standard dielectric and magneto-dielectric samples are tested using the proposed scheme in order to retrieve their permittivity and permeability values. The measured data of each sample are in good match with the corresponding reference values available in literature having a typical error of less than 6%.

α-MnO2/h-MoO3 hybrid metal oxide materials with different weight ratios were successfully synthesized. The prepared nanocomposite material has been demonstrated to be an electrode material for potential application in electrochemical charge storage devices as well as an efficient photocatalyst for dye degradation. The results showed high ionic conductivity, better charge transfer ability, viability for high current density, and enhanced specific capacitance (Sc) with appreciable cyclic stability. Electrochemical performances of the prepared materials were investigated by cyclic voltammetry (CV) analysis, galvanostatic charge–discharge (CD) techniques, and electrochemical impedance spectroscopy (EIS). We were able to achieve a maximum Sc value of 412 F/g and 358 F/g at a current density of 1 A/g for the composite with 25% h-MoO3 mass loading from a three electrode cell and two electrode symmetric cell configuration, respectively, and it could deliver an outstanding energy density of 50 Wh kg–1 with a power...

We discuss photo-luminescence characteristics of CdSe core/shell quantum dots at cryogenic temperatures using a hybrid system of a single quantum dot and an optical nanofiber. The key point is to control the emission species of quantum dot to charged excitons, known as trions, which have superior characteristics to neutral excitons. We investigate the photocharging behavior for the quantum dots by varying the wavelength and intensity of irradiating laser light, and establish a method to create a permanently charged situation which lasts as long as the cryogenic temperature is maintained. The present photocharging method may open a new route to applying the CdSe quantum dots in quantum photonics, and the hybrid system of photocharged quantum-dot and optical nanofiber may readily be applicable to a fiber-in-line single-photon generator.

We demonstrate a fiber in-line single photon source based on a hybrid system of colloidal single quantum dots deposited on an optical nanofiber and cooled down to cryogenic temperature (3.7 K). We show that a charged state (trion) of the single quantum dot exhibits a photo-stable emission of single photons with high quantum efficiency, narrow linewidth (3 meV FWHM) and fast decay time ($$10.0\pm 0.5$$ ns). The single photons are efficiently coupled to the guided modes of the nanofiber and eventually to a single mode optical fiber. The brightness (efficiency) of the single photon source is estimated to be $$16\pm 2\%$$ with a maximum photon count rate of $$1.6\pm \,0.2$$ MHz and a high single photon purity ($$g^2(0)=0.11\pm 0.02$$). The device can be easily integrated to the fiber networks paving the way for potential applications in quantum networks.

Dopamine (DA) is a significant neurotransmitter in the central nervous system that controls many physiological functions. The abnormal or imbalance of DA levels in the human body remarkably affects the physiological functions. Therefore, to detect and monitor DA levels in the human body is necessary to control the body functions. In this context, we have prepared well-defined three-dimensional (3D) polyhedron structured lanthanum manganite nanoparticles (LaMnO3 NPs) by using conventional (Cp) and lemon-juice (Lj) assisted routes and utilized as an electrocatalyst for the sensitive and selective electrochemical detection of DA. The crystalline phase and structure of as-prepared LaMnO3 NPs are confirmed by XRD, XPS and TEM analyses. The Lj-LaMnO3 NPs modified glassy carbon electrode (GCE) shows enhanced electrocatalytic activity towards DA oxidation with lower potential compared to the Cp-LaMnO3 NPs and bare GC electrodes. Moreover, Lj-LaMnO3 NPs/GCE exhibited a wide detection window (1–600 µM), lower detection limit (32 nM), good selectivity and stability. Besides, the modified electrodes are successfully used in the real samples analysis such as urine and saliva samples and the obtained recovery values are good and satisfactory. Hence, the Lj-LaMnO3 NPs/GCE can be used to determine the DA level and offers a best matrix for pharmaceutical applications.

A novel split-ring resonator (SRR)-based microwave sensor for accurately determining the real parts of the complex permittivity and the complex permeability of magnetodielectric composites is proposed. The proposed sensor is realized using the microstrip technology, where two SRRs coupled magnetically with the microstrip line are printed on two sides of the line. The sensor is designed using the full-wave electromagnetic solver and its equivalent circuit model is obtained. A numerical model of the proposed sensor is developed for extracting the magnetic and the dielectric properties of the sample under test in terms of change in resonance frequency after loading the device with the test specimen. The proposed methodology is validated by fabricating the sensor on RT/duroid 6006 substrate and testing various standard dielectric and magnetodielectric samples viz. Teflon, Poly vinyl chloride, Plexiglas, Polyethylene, Carbonyl iron, Ni0.6Co0.4Fe2O4, and Cobalt (30%)/Polystyrene composite in S-band. The measured relative permeability and the relative permittivity of the test specimens are found to be in close agreement with their values available in literature with maximum error of less than 8%.

Non-invasive inspection, material evaluation and characterization are of paramount importance for quality control and structural health monitoring in various applications. Microwave imaging modalities have proven significant potential in such applications. Herein, a substrate integrated waveguide cavity-backed slot antenna is designed to operate in the X-band frequency range. The proposed antenna is modeled and analyzed using an electromagnetic simulation software, and its near-field characteristics are verified experimentally. The utility of the proposed antenna for imaging applications is demonstrated by imaging low-loss and high-loss material samples.

Background: The duration and dosage of prophylactic antibiotics vary substantially among surgeons. This study explored the outcome and efficiency of short-term antibiotic prophylaxis in head and neck procedures. Methods: One hundred and forty-three patients undergoing various head and neck surgical procedures were included. They were categorized into two groups, clean (Group C) and clean-contaminated (Group CC). They received short-term prophylaxis with intravenous (IV) antibiotics. Group C patients received single dose IV antibiotic at induction and Group CC received antibiotic for 3 days. The scoring methods such as American Society of Anesthesiologist (ASA) score, National Nosocomial Infections Surveillance (NNIS) score, and additional treatment, discharge, erythema, purulent discharge, separation of deep tissue, isolation of bacteria and stay (ASEPSIS) were used. Scoring methods were used to analyze the risk factors and complications up to a period of 4 weeks postoperatively. Results: There were 83 patients in Group C and 60 patients in Group CC. Parameters such as body weight, body mass index (BMI), biochemical and hematological parameters along with surgical details, and postoperative wound assessment were analyzed. A significant association of surgical site infection (SSI) with BMI, anemia, hypoalbuminemia, and tobacco usage was noted along with a high incidence of SSI in surgical procedures involving the larynx. There was no significant relationship with ASA score and NNIS score. Conclusion: Short-term antibiotic prophylaxis in clean and clean-contaminated cases is feasible and effective as long-term prophylaxis. Correction of anemia, hypoalbuminemia, weight reduction, and avoidance of tobacco can prevent SSIs.

Manganese dioxide and Manganese dioxide based materials have long been used in various energy storage systems because of their outstanding electrochemical behavior, low cost, and environmental compatibility. In recent years, many studies had focused on its nano scale applications due to the structural flexibility and the unique physicochemical properties. The basic crystal structure of manganese dioxide configures of one manganese atom surrounded by six oxygen atoms to form an octahedron. Here β-MnO2, γ-MnO2, λ-MnO2 and δ-MnO2 nanoparticles have been successfully synthesized by simple precipitation methods. Powder X-Ray Diffraction (XRD) analyses were performed for the identification and examination of the crystalline phase structures. Presence of functional groups and purity of the sample were evaluated by Fourier Transform Infrared Spectroscopy (FTIR). Morphology studies were carried out via Scanning Electron Microscopy (SEM). Electrochemical performances of the β, γ and δ phases were characterized by cyclic voltammetry (CV), Galvanostatic Charge-Discharge (GCD) and Electrochemical Impedance Spectroscopy (EIS). Among the four electrodes, δ-MnO2 exhibited the highest value for specific capacitance. These results show that the prepared MnO2 electrodes are good materials for supercapacitor application, especially δ-MnO2.

A new microwave sensor for subw ave length imaging is developed and its performance is experimentally verified. The proposed sensor is based on an electrically small loop loaded with a spiral resonator of miniaturized footprint (7.2 mm × 7.2 mm). While the resonance frequency of the sensor is 426 MHz (free-space wavelength λ = 704.2 mm), imaging resolution of around 5 mm (∼ A/140) is attained as demonstrated herein.

The e-MnO2 Nanoparticle was synthesized through wet chemical method. The phase formation and crystalline structure were well understood by powder X-ray diffraction (XRD). Presents of further impurities or functional group studies were carried out by Fourier transform infrared spectroscopy (FTIR). Further the formation of MnO2 particles is confirmed by Raman spectroscopy. The weight loss as well as the heat flow associated with the thermal decomposition was studied by thermogravimetric analysis (TGA) along with differential thermal analysis (DTA). The electrochemical behavior of the prepared MnO2 nanoparticles were investigated by cyclic voltammetry (CV), Galvenostatic charge-discharge techniques and electrochemical impedance spectroscopy (EIS).

In this paper, a non destructive technique is presented for detection of adulteration in common edible oils using the proposed microwave planar resonant sensor. The proposed sensor is operating in the ISM (industrial, scientific and medical) frequency band of 5.85 GHz. The sensor is designed using the full wave electromagnetic solver, the CST Microwave Studio, and an empirical model of the proposed sensor is developed for the accurate calculation of complex permittivity of standard edible oil samples under test in terms of the resonant frequency under loaded condition. The developed model is then used to detect the percentage adulteration of contaminants in the pure edible oil samples. The designed resonant sensor is fabricated on a 1.6 mm FR4 substrate. A sample container made of borosilicate glass is specially designed to make the overall procedure to be non-contacting and nondestructive. The fabricated sensor is finally tested for detecting adulteration with different concentration levels in edible oils.

In this work, a simple microwave resonant sensor is proposed for detection of small amount of oil spill in sea water. The sensor is realized using the microstrip technology, and the geometry of the resonant structure is optimized in order to improve the sensitivity. The proposed sensor is designed to operate at 5.85 GHz in the industrial, scientific, and medical (ISM) band. The structure of the sensor is modeled in full wave electromagnetic solver, CST Microwave Studio and the dimensions of the sensor are chosen to get the desired operating frequency. The designed sensor is finally fabricated, and is employed for detection of small amount of petroleum products present in the water. The measured results show that the proposed sensor is capable of detecting up to 5 % of petrol in water.

Increased depletion of fossil fuels along with global warming and climate change made the society to think about alternate green and sustainable energy sources and better energy storage devices. Extensive research has been performed on the development of solar cells, fuel cells, Lithium- ion battery and supercapacitors to combat the green house effect and its consequences, and to meet the increased energy crisis. Supercapacitors, also known as electrochemical capacitors are gained a great attention because of their pulse power supply, long cycle life (>100,000), simple principle and high dynamic of charge propagation. Its greater power density than lithium- ion battery and much larger energy density than conventional capacitors brought super capacitors to a promising energy storage device to meet the increased energy demands. Here we demonstrate supercapacitor electrode materials with graphene oxide (electric double layer capacitor) and α-MnO 2 nanomaterial (pseudo-capacitor), as well as composite of these materials, which means that the bulk of the material undergoes a fast redox reaction to provide the capacitive response and they exhibit superior specific energies in addition to the carbon-based supercapacitors (double-layer capacitors). A simple soft chemical route is utilized to synthesize graphene oxide, α-MnO 2 and graphene oxide-MnO 2 composite. The phase and the structure of the synthesized materials are studied using X-ray diffractometry (XRD). The functional group and the presence of impurities are understood from Fourier transform infrared (FTIR) spectra. The capacitive properties of the graphene oxide, graphene oxide - MnO 2 nanocomposite and α-MnO 2 are tested with the help of cyclic voltammetry (CV) and galvanostatic charge – discharge techniques using 1 M Na 2 SO 4 in aqueous solution as electrolyte. It was found that graphene oxide - MnO 2 nanocomposite shows better electrochemical behaviour compared to individual graphene oxide and α-MnO 2 nanomaterial.

MnO2 nanoparticles were synthesized by simple chemical precipitation method and were subjected to different heat treatment process. The structural evolution of as-prepared MnO2 nanoparticles at different annealing temperature was confirmed by XRD analysis. The weight loss as well as the heat flow associated with the thermal decomposition was studied by thermogravimetric analysis (TGA) along with differential thermal analysis (DTA). The functional group and phase formation were confirmed by Fourier transform infrared spectroscopy (FTIR). Finally electrochemical properties were evaluated using cyclic voltammetry (CV) and galvanostatic charge-discharge techniques. The cyclic voltammogram and charge-discharge curve of 450 ˚C annealed MnO2 nanoparticles exhibited relatively good capacitive behavior.

The α-MnO2 nanoparticles were synthesized for supercapacitor electrode application by controlled co-precipitation method. The as-prepared sample was annealed at different temperature to enhance the crystallinity and it is confirmed with XRD analysis. The electro chemical behavior and conductivity of the material were investigated by cyclic voltammetry with charge-discharge techniques and AC Impedance analyzer.

Time-delayed intensity–interferometry (TDII) measurements of the fluorescent emission from an ultracold ensemble of thermal 87Rb atoms in a steady-state magneto-optical trap are presented, which reveal the underlying coherent and incoherent dynamics of the atoms. Measurements carried out with a 5 ns time resolution yielded a second-order intensity correlation function with the theoretically predicted value of 2 at zero delay. In addition coherent Rabi oscillations were seen for up to five full periods—much longer than the spontaneous emission lifetime of the excited state of Rb. The oscillations were damped out by ~150 ns, and thereafter an exponential decay observed, from which the mean velocity of atoms and thus, the temperature of the ensemble was estimated. The values so obtained compare well with those determined by standard techniques. It is seen that TDII permits a quantitative study of the coherent and incoherent processes, even in a large ensemble of independent atomic emitters in random thermal motion. This measurement of second-order correlation powerful technique can reveal hidden periodicities such as coherent Rabi oscillations that are not directly seen in the emission from a large collection of atoms. In addition it can also reveal information about the mean velocity of the thermal ensemble of emitters, even though the Doppler broadening of emission due to the motion of atoms is smaller than the natural linewidth and is not directly measureable.

Time-delayed intensity-interferometry employing light emitted by an ensemble of laser-cooled rubidium atoms was used to determine its temperature on timescales of microseconds, and to observe signatures of coherent population oscillations on time scales of nanoseconds.

The large scale energy production and developments in renewable energy sources requires efficient energy storage systems. The physical and chemical charge storage techniques along with high power and energy density brought electrochemical supercapacitors (ECs) as a versatile power source. The high rates of charging and discharging with long cycle life as well as the economical and eco-friendly nature support ECs to various energy applications. Since the last couple of decades, Supercapacitors with various metal oxides as electrode materials got a great interest among researchers. Here we synthesised α-MnO2 nanoparticles by simple chemical precipitation method and are subjected to heat treatment at 300 ˚C, 500 ˚C and 700 ˚C. The structural formation of as- prepared and annealed MnO2 are confirmed by XRD analysis. The functional group and optical absorption studies are done by Fourier transform infrared spectroscopy (FTIR) and UV visible spectroscopy. The surface area of the samples is measured using Brunauer-Emmett-Teller (BET) method. Finally electrochemical properties are evaluated using cyclic voltammetry (CV) and galvanostatic charge-discharge techniques. The cyclic voltammogram and charge-discharge curve recorded indicates MnO2 nanoparticles annealed at 300 ˚C for 5 h shows better electrochemical behaviour.