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To increase storage capacity of supercapacitor nanomaterials plays an important role. By using different surfactants, it is possible to synthesize nanomaterials. Surfactants have power overgrowth and agglomeration of particles, which control the dimension of the materials. Doping of vanadium contributes to improvement the electric conductivity of nickel hydroxide. Compared with those of cetyltrimethylammonium bromide (CTAB) and ammonium fluoride (NH4F), the restricted specific capacitance of these materials increases due to the use of the sodium lauryl sulphate (SDS) surfactant. The maximum specific capacitance was from a GCD of 2150 F g−1 (1825 mF cm−2) at 3 mA cm−2 and from a CV of 1844 F g−1 at a 10 mV s−1 scan rate. After 1000 charge‒discharge cycles, the electrode shows better stability at almost 95.5% at a scan rate of 100 mV s−1. The diffusion and capacitive-controlled specific capacitance calculated with respect to different surfactants is a key aspect of this work. [ABSTRACT FROM AUTHOR]

Accelerating depletion of traditional fossil fuel and global warming demand highly efficient, cost-effective, and scalable electrocatalysts for energy conversion processes (water splitting) and energy storage devices (supercapacitor). In this work carbon quantum dot (CQD) decorated NiCo-LDH was successfully prepared on nickel foam as an electrocatalyst for oxygen evolution reaction (OER) and supercapacitor via a facile two-step hydrothermal pathway. Benefiting from improved electrical conductivity with CQD the synthesized CQD/NiCo-LDH showed remarkable electrochemical behavior than NiCo-LDH. The CQD/NiCo-LDH and NiCo-LDH generated a current density of 10 mA/cm2 at an overpotential of 226 and 332 mV with Tafel slope of 125 and 147 mV/dec, respectively. In addition, CQD/NiCo-LDH electrodes exhibited specific capacitance of 1136 and 441 F/g at 1 and 10 A/g current density, respectively, and cycling stability of almost 62% specific capacitance retention after 500 charge–discharge cycles. [ABSTRACT FROM AUTHOR]

The spinel ferrites are versatile group of metal oxides with good photoelectrochemical and unique magnetic properties, as well as low cost, biocompatible and huge abundance. The magnetic as well as photoelectrochemical properties have been extensively examined. Herein, we have synthesized zinc ferrite (ZnFe2O4) thin films on nickel foam via spray pyrolysis method at substrate temperatures of 300, 400, and 500 °C. The physicochemical properties of ZnFe2O4 films were investigated using X-ray diffraction, scanning electron microscopy, energy dispersive X-ray analysis and fourier transform infrared spectroscopy (FT-IR) spectroscopy. Electrochemical properties oxygen evolution reaction and supercapacitive performance of ZnFe2O4 thin films were investigated through linear sweep voltammetry, cyclic voltammetry, galvanostatic charge-discharge, and electrochemical impedance spectroscopy. The ZnFe2O4 thin film synthesized at 400 °C exhibited an overpotential of 319 mV at a current density of 50 mA/cm2 with a Tafel slope of 115 mV/dec. Furthermore, it also showed a specific capacitance of 335 F/g at 1 mA/cm2 current density in 1 M KOH electrolyte. [ABSTRACT FROM AUTHOR]

A supercapacitor is a high-capacity device that interfaces electrolytic capacitors and batteries by possessing a capacitance value significantly larger than conventional capacitors but with lower voltage limits. Nickel hydroxide is a potential material exhibiting tempting properties such as high specific capacitance, various oxidation states, morphologies, and large surface area. However, various limitations must be overcome, such as increasing the current density and improving the stability after doping of vanadium in Ni(OH)2 material-doped Ni(OH)2microflowers were successfully fabricated using a chemical bath deposition process in this study. XRD studies show hexagonal crystal structure with γ-phase of Ni(OH)2. The presence of V=O at peak positions 1023, and 923 cm−1 reveals in the FT-IR study. Increased interlayer distance demonstrates the presence of vanadium ions between the superior and inferior layers of Ni(OH)2. The 0.3% V-doped Ni(OH)2 electrode displayed a remarkable specific capacitance of 1456.8 F g−1 at 3 mA cm−2 and high performance with 88.17% capacity retention at a scan rate of 100 mV s−1 over 2000 cycles. [ABSTRACT FROM AUTHOR]

Current work clearly demonstrates Pd sensitization on hydrothermally prepared vanadium pentoxide (V2O5) and on its composite with reduced graphene oxide (rGO) by a simple dip and dry method for NO2 gas sensing. Orthorhombic crystal structure of prepared sample was confirmed with the help of X-Ray Diffraction (XRD) technique. The presence of palladium (Pd) was confirmed by energy-dispersive spectroscopy (EDS) and X-Ray photoelectron spectroscopy (XPS), while fourier transform infra-red (FTIR) spectroscopy for functional group detection. Porous nano-structure morphology was confirmed with the help of scanning electron microscopy (SEM). Transmission electron microscopy (TEM) technique confirms presence of Pd nanoparticles (NPs) with an average diameter of ~ 20 nm. The photoluminescence (PL) peak arising at 641.75 nm gives the confirmation to the mid-gap states generated by oxygen vacancies. Finally, the gas-sensing performance of the prepared sensing material was measured with the help of a RIGOL digital multimeter. The result shows that 33.68% gas response towards 100 ppm NO2 gas at relatively low-working temperature (150 °C) along with considerable 47 and 592 s response/recovery time, respectively. The sensing material shows good reproducibility and high stability (Gas Response ~ 29%) even after 63 days. Hence Pd sensitized V2O5- rGO is a promising candidate for gas sensors working at relatively low working temperatures. [ABSTRACT FROM AUTHOR]

In the present investigation, Ni (OH)2 microflowers were successfully deposited on a cost-effective stainless steel electrode by a simple chemical bath deposition method (CBD). The optimized deposition time and heating temperature. Potassium persulphate shows an important role as an oxidizing agent and controlled the growth of nanostructure. Deposited Ni(OH)2 shows α phase but due to persulphate ion one hydrogen removes and it converted into γ phase. The Ni(OH)2 deposited using CBD method at 2 h then heated at 100 °C temperature give better specific capacitance. For a current density of 3.0 mA cm−2, the computed highest specific capacitance becomes 669 F g−1. After 1000 cycles, electrode material shows good capacitive retention of about 78% and high coulombic efficiency of 99.3%. The impressive results proffered above indicate that Ni(OH)2 is a promising electrode material with excellent supercapacitor performance. [ABSTRACT FROM AUTHOR]

Titanium doped WO (Ti doped WO) nanostructures were synthesized by hydrothermal synthesis by the controlled hydrolysis of NaWO using oxalic acid and Titanium tetrachloride. Prepared samples were characterized by X-ray powder diffraction (XRD), scanning electronic microscopy (SEM), and transmission electron microscopy (TEM). As-synthesized pristine WO showed nanorods with diameters of about 10-15 nm and length about 1.2 µm and Ti doped WO composed of numerous small nanocrystals. Introduction of Ti doping by chemical synthesis process suppressed the growth of one-dimensional nanorods along their axis direction and shows agglomeration of particulate like morphology and no elongated structures. Ti doping not only lowered the optimal operating temperature of WO nanostructures sensors from 250 to 200 °C but also increased the maximum value of sensor response. Also the Ti-doped WO nanostructures exhibited rapid response characteristic to NO gas compared to pristine WO. [ABSTRACT FROM AUTHOR]

Aim: This in vitro study aimed to evaluate the efficacy of rotary ProFile, ProTaper, Hero Shaper and K-files in shaping ability, cleaning efficacy, preparation time and instrument distortion in primary molars. Methods: Sixty extracted primary mandibular second molars were divided into four equal groups: Group I K-file, Group II ProFile, Group III ProTaper file and Group IV Hero Shaper file. The shaping ability was determined by comparing pre- and post-instrumentation CBCT scans and data analysed with SPSS program using the Chi-square test. Cleaning efficacy was evaluated by the degree of India ink removal from the canal walls under stereomicroscopy. Instrumentation times were calculated for each tooth and instrument distortion was visually checked and duly noted. The cleaning efficacy and instrumentation time were determined using ANOVA with Tukey's correction. Instrument distortion was analysed using Chi-square test. Results: The canal taper was significantly more conical for rotary files as compared to K-files with Chi-square test ( p < 0.05). Cleaning efficacy of rotary files with average scores (Groups II- 0.68, III- 0.48 and IV- 0.58) was significantly better than K-files (Group I- 0.93) ( p < 0.05). Mean instrumentation time with K-file (20.7 min) was significantly higher than rotary files (Groups II 8.9, III 5.6, and IV 8.1 min) ( p < 0.05). Instrument distortion was observed in Group I (4.3 %), while none of the rotary files were distorted. Conclusions: Rotary files prepared more conical canals in primary teeth than manual instruments. Reduced preparation time with rotary files enhances patient cooperation especially in young children. [ABSTRACT FROM AUTHOR]

Composite WO-NbO thin films were deposited on the glass and fluorine-doped tin oxide (FTO)-coated glass substrates using simple and inexpensive spray pyrolysis technique. The process parameters, like nozzle-to-substrate distance, spray rate, concentration of sprayed solution, etc., were optimized to good quality films. The films were characterized for the structural, morphological, optical, and electrochromic properties. Structural and morphological characterizations of the films were carried out using scanning electron microscopy and X-ray diffraction techniques. Electrochemical properties of the Composite WO-Nb2O thin films were further studied using cyclic-voltammetry, chronoamperometry, chronocoulometry, and electrochemical Impedance spectroscopy. [ABSTRACT FROM AUTHOR]