Anil A. Kashale

Bio-green synthesis of Ni-doped tin oxide nanoparticles and its influence on gas sensing properties

Considering the potential applications of transition metal doped nanostructured materials and the advantages of novel, cost-effective and environmentally friendly biosynthesis methods, Ni-doped SnO2 nanomaterials have been synthesized using remnant water (ideally kitchen waste) collected from soaked Bengal gram bean (Cicer arietinum L.) extract. The structural and optical properties of the Ni-doped SnO2 nanostructures were studied using various techniques such as UV/visible spectroscopy, FT-IR spectroscopy, X-ray powder diffraction (XRD), field-emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM). The SEM and TEM images and the XRD results of the biosynthesized Ni–SnO2 nanoparticles reveal a uniform size distribution with an average size of 6 nm and confirmed the formation of a rutile structure with the space group (P42/mnm) and the nanocrystalline nature of the products with a spherical morphology. Subsequently, Ni-doped biosynthesized SnO2 nanoparticles were coated onto a glass substrate using the doctor blade method to form thin films. The NO2 sensing properties of the materials have been studied in comparison with other gases. The reported gas sensing results are promising, which suggest that the Ni-dopant is a promising noble metal additive to fabricate low cost SnO2 based sensors.

Room Temperature Ammonia Gas Sensing Properties of Biosynthesized tin Oxide Nanoparticle Thin Films

The authors are thankful to UGC-DAE Consortium for Scientific Research, Indore (Project Ref. No.: CSR-I/CRS-48/48) and UGC, New Delhi (F. No. 41-370/2012 (SR)) for the financial support. We are also thankful to the Department of Nanotechnology, Dr. Babasaheb Ambedkar Marathwada University, Aurangabad for providing the laboratory facility.

Binder free 2D aligned efficient MnO2 micro flowers as stable electrodes for symmetric supercapacitor applications

Herein, δ-MnO2 micro-flower thin films are grown directly onto a stainless steel mesh via a simple rotational chemical bath deposition technique. Moreover, the influence of the concentration of precursor ratio of MnSO4 : KMnO4 is investigated and the obtained samples are designated as M1 (KMnO4 : MnSO4 = 3 : 1), M2 (KMnO4 : MnSO4 = 3 : 2) and M3 (KMnO4 : MnSO4 = 3 : 3). The concentration of MnSO4 as a starting material has a significant influence on the reaction kinetics, which subsequently alters the morphology and also the electrochemical performance. Among these three electrodes, the M1 electrode exhibits a high specific capacitance of 376 F g−1 at a current density of 5 mA cm−2 and a high specific energy of 52 W h kg−1, which is higher than M2 (specific capacitance 312 F g−1 and specific energy 43 W h kg−1) and M3 (specific capacitance 283 F g−1 and specific energy 39 W h kg−1) electrodes. Due to the interesting performance of the M1 based electrode, the symmetric device is fabricated using two electrodes M1 (3 : 1) and represented as SSM/M1//M1/SSM. The device provides a maximum specific capacitance of 87 F g−1 and specific energy density of 32 W h kg−1 at a current density of 5 mA cm−2. In addition, the symmetric device of the M1 electrode also exhibits good cycle stability showing 138% capacitance retention up to 2500 cycles. The enhanced electrochemical performance could be attributed to the direct growth of micro-flowers of MnO2 on a stainless steel mesh, which provides more pathways for easy diffusion of electrolyte ions into the electrode. This study provides new insight and pathways for the development of low-cost and high-performance energy storage devices.

Biomass-Mediated Synthesis of Cu-Doped TiO2 Nanoparticles for Improved-Performance Lithium-Ion Batteries

Pure TiO2 and Cu-doped TiO2 nanoparticles are synthesized by the biomediated green approach using the Bengal gram bean extract. The extract containing biomolecules acts as capping agent, which helps to control the size of nanoparticles and inhibit the agglomeration of particles. Copper is doped in TiO2 to enhance the electronic conductivity of TiO2 and its electrochemical performance. The Cu-doped TiO2 nanoparticle-based anode shows high specific capacitance, good cycling stability, and rate capability performance for its envisaged application in lithium-ion battery. Among pure TiO2, 3% Cu-doped TiO2, and 7% Cu-doped TiO2 anode, the latter shows the highest capacity of 250 mAh g–1 (97.6% capacity retention) after 100 cycles and more than 99% of coulombic efficiency at 0.5 A g–1 current density. The improved electrochemical performance in the 7% Cu-doped TiO2 is attributed to the synergetic effect between copper and titania. The results reveal that Cu-doped TiO2 nanoparticles might be contributing to the enhanced electronic conductivity, providing an efficient pathway for fast electron transfer.