Shivaji University

About: Shivaji University is a education organization based out in Kolhāpur, Maharashtra, India. It is known for research contribution in the topics: Thin film & Scanning electron microscope. The organization has 3078 authors who have published 5295 publications receiving 115397 citations.

Metal Precursor Dependent Synthesis of NiFe2O4 Thin Films for High-Performance Flexible Symmetric Supercapacitor

Abstract: Herein, we report the chemical synthesis of NiFe2O4 thin films forming nanosheet-, nanoflower-, and nanofeather-like morphologies using NiCl2·6H2O, Ni(NO3)2·6H2O, and NiSO4·6H2O nickel salt precursors, respectively, while using the same iron salt precursor. A nanostructure formation mechanism is proposed in detail using coordination chemistry theory. Interestingly, nanostructures of NiFe2O4 nanosheets revealed a maximum surface area of 47 m2 g–1, which was higher than those of nanoflowers and nanofeathers (25 and 11 m2 g–1). Similarly, the supercapacitive properties of the individual NiFe2O4 nanosheet-based electrode demonstrated maximum specific capacitance of 1139 F g–1, which is found to be better than that of NiFe2O4 nanoflowers (677 F g–1) and nanofeathers (435 F g–1) in 6 M KOH electrolyte. Furthermore, the symmetric device fabricated using NiFe2O4 nanosheet electrodes and PVA-KOH solid gel electrolyte shows higher specific capacitance of 236 F g–1 with 98% retention after 7000 cycles and higher spe...

Effect of methyltrimethoxysilane as a co-precursor on the optical properties of silica aerogels

Abstract: To produce monolithic durable hydrophobic silica aerogels with high direct optical transmittance and low diffusion of light, systematic and detailed experimental investigations were carried out by adding methyltrimethoxysilane (MTMS) in the sol–gel processing of silica alcogels. The alcogels were dried supercritically using the high temperature alcohol method. A series of aerogel samples of different molar ratio combinations (0–1.85) of MTMS/tetramethoxysilane (TMOS) was optically examined in the UV–Visible–NIR range by a spectrophotometer equipped with an integrating sphere. The overall transmittance of the aerogels in the visible range decreased from 93% to 10% with increased MTMS/TMOS molar ratio (A) from 0 to 1.65, respectively. The most relevant parameter being studied was the direct/hemispherical transmittance ratio (τ). The hydrophobicity of the aerogels was measured from the contact angle and it varied from 50° to 140° depending upon the molar ratio combination, the higher being for the higher A value. A good compromise of high direct optical transmittance (τ≈80% at 750 nm for 1 cm thick sample) for durable hydrophobic (θ≈110°) aerogels with low volume shrinkage (

Potassium Phosphate Catalyzed a Rapid Three-Component Synthesis of Tetrahydrobenzo[b]pyran at Ambient Temperature

Abstract: An efficient, rapid, one-pot synthesis of tetrahydrobenzo[b]pyran is achieved via a three-component reaction of aldehydes, 1,3-diketone, malononitrile in 20% ethanol using anhydrous potassium phosphate as a catalyst at room temperature. The key advantages are the short reaction time, high yields, simple work-up, inexpensive catalyst and purification of products by non-chromatographic methods, i.e. by simple recrystallization from ethanol. An efficient, rapid, one-pot synthesis of tetrahydrobenzo[b]pyran is achieved via a three-component reaction of aldehydes, dimedone, malononitrile in 20% ethanol using anhydrous potassium phosphate as a catalyst at room temperature. The key advantages are the short reaction time, high yields, simple work-up, inexpensive catalyst and purification of products by non-chromatographic methods, i.e. by simple recrystallization from ethanol.