Abasaheb Garware College of Arts and Science (commonly referred to as Garware College) is a college located in Pune, India. It is run by the Maharashtra Education Society, a private education institution founded by Vasudeo Balwant Phadke, Vaman Prabhakar Bhave and Laxman Narhar Indapurkar in 1860. The college was established in 1945 and named as "M.E.S College of Arts and Science". It was renamed to its present name in 1970s after a charitable donation by the industrialist Abasaheb Garware to the society.[citation needed]Garware College offers undergraduate programs in Arts and Science. Approximately 5000[citation needed] students study in this college.
This study investigates the topotactic conversion of cobalt hydroxide (CHY) to cobalt oxide (COX) and its influence on electrochemical performance. CHY was synthesized by a simple precipitation method and thermally decomposed in a muffle furnace at 300 degrees C for 2 h to obtain Co3O4. The CHY and COX were thoroughly characterized by thermogravimetric analysis (TGA), X-ray diffraction (XRD), Raman spectroscopy, and Fourier transform infrared (FTIR) spectroscopy. Field emission scanning electron microscopy (FESEM) images revealed that the nanorod morphology of the hydroxide was retained after calcination. Characterizations confirmed successful topotactic transformation of alpha-Co(OH)(2) to Co3O4 without any secondary phase. Electrochemical measurements demonstrated a significant difference in charge-storage behavior: CHY exhibited a specific capacitance of 570 F g(-1) at 1 A g(-1), while COX showed 188 F g(-1) under identical conditions. Cyclic voltammetry performed at scan rates from 2.5 to 100 mV s(-1) and galvanostatic charge-discharge (GCD) at 0.5-8 A g(-1) further supported the enhanced pseudocapacitive behavior of CHY. Electrochemical impedance spectroscopy (EIS) revealed a much lower charge-transfer resistance for CHY compared to COX, indicating faster electron transport. The results confirm that the topotactic transformation preserves morphology and improves structural stability, although it reduces ion diffusion and available active surface area, resulting in lower capacitance in the oxide phase.
The present study investigated the antibacterial and antifungal activity of cerium oxide nanocubes (CeO2 NCs) and evaluates how annealing temperature influences their structural, morphological, optical, and colloidal properties. Structural and microstructural investigations of the samples were performed using XRD and Raman spectroscopy. The XRD results revealed a cubic fluorite structure, which was consistent with the Raman analysis. FESEM revealed cubical morphology with average particle size was estimated to be 35-50 nm, while energydispersive X-ray spectroscopy (EDS) verified the elemental composition. In addition, colloidal stability of CeO2 NCs was investigated using dynamic light scattering (DLS) and zeta potential (ZP) measurements, which provided information on the particle size and surface charge distribution, respectively. Reactive oxygen species generation was investigated using the DCPIP assay. The as-prepared sample exhibited minimum inhibitory concentration (MIC) values of 250 & micro;g/mL (37.03%) and 500 & micro;g/mL (39.28%) against S. aureus and E. coli, respectively, whereas the annealed samples required 1000 & micro;g/mL to inhibit S. aureus and E. coli. Antifungal activity of both the as-prepared and annealed 300 degrees C samples was observed at 1000 & micro;g/mL (45.83%), while no activity was observed for the annealed 400 degrees C sample against A.niger.
One of the most important challenges in environmental remediation, especially for the treatment of wastewater contaminated with dyes, is the development of highly effective and readily recoverable photocatalysts. In order to overcome this, novel magnetically separable Cu0.5Ni0.5MnxFe2-xO4 (where x = 0.0-1.0) nano ferrites were successfully synthesized using a sol-gel auto-combustion technique and annealed at 800 degrees C. X-ray diffraction (XRD) analysis confirmed the formation of a single-phase spinel structure, while Raman spectroscopy revealed slight structural distortions induced by Mn doping. FESEM and TEM characterizations exhibited an aggregated morphology of partially developed nanoparticles, with elemental composition and oxidation states validated by EDX and XPS, respectively. Crucially for practical catalyst recovery, VSM analysis demonstrated robust magnetic properties; although the saturation magnetization (Ms) decreased from 64.176 emu/g to 30.995 emu/g with increasing Mn substitution, the ferrites retained sufficient magnetization for rapid and facile separation from the reaction medium using an external magnet. The optical band gap, estimated via UV-DRS, indicated favourable solar light absorption. The photocatalytic efficacy of these nano ferrites was evaluated through the degradation of Reactive Orange (RO) dye under natural solar irradiation. Remarkably, the x = 1.0 composition exhibited the highest photocatalytic degradation efficiency, benefiting from optimized band structure and enhanced charge carrier separation. Furthermore, the catalyst demonstrated excellent stability and reusability over multiple cycles. These findings establish the Cu0.5Ni0.5MnxFe2-xO4 system as a highly promising, magnetically recoverable platform for practical and sustainable wastewater treatment.
The ability of an indigenous marine actinomycete, Nocardiopsis dassonvillei NCIM 5124, to remove hexavalent chromium [Cr (VI)] in the free and calcium alginate immobilized form was evaluated. While field emission scanning electron microscope (FESEM) studies revealed the mycelial and porous nature of the free and immobilized biosorbents, respectively, thermogravimetric analysis indicated their thermal stability. In the free form, the biomass removed 76.98 +/- 1.77% Cr (VI), while lesser quantities of immobilized N. dassonvillei (0.12 g) mediated the removal of 84.55 +/- 1.92% of Cr (VI) under optimized conditions. FESEM-energy dispersive X-ray (FESEM-EDX) revealed the presence of chromium on the biosorbents, and Fourier transform infrared analysis suggested that amide, amino, carbonyl, hydroxyl, and phosphate groups were involved. Brunauer-Emmett-Teller (BET) analysis confirmed the mesoporous nature of the beads. For the free and immobilized biosorbents, the biosorption occurred onto monolayers and multilayers, respectively via chemisorption. The negative values of Delta G observed during the thermodynamic studies revealed the spontaneous and endothermic nature of the biosorption process. This is the first study to show that alginate immobilized N. dassonvillei biomass can act as an effective biosorbent for eliminating potentially harmful Cr (VI) ions in an environmentally acceptable manner.
This study investigates the topotactic conversion of cobalt hydroxide (CHY) to cobalt oxide (COX) and its influence on electrochemical performance. CHY was synthesized by a simple precipitation method and thermally decomposed in a muffle furnace at 300°C for 2 h to obtain Co 3 O 4 . The CHY and COX were thoroughly characterized by thermogravimetric analysis (TGA), X‐ray diffraction (XRD), Raman spectroscopy, and Fourier transform infrared (FTIR) spectroscopy. Field emission scanning electron microscopy (FESEM) images revealed that the nanorod morphology of the hydroxide was retained after calcination. Characterizations confirmed successful topotactic transformation of α ‐Co(OH) 2 to Co 3 O 4 without any secondary phase. Electrochemical measurements demonstrated a significant difference in charge‐storage behavior: CHY exhibited a specific capacitance of 570 F g −1 at 1 A g −1 , while COX showed 188 F g −1 under identical conditions. Cyclic voltammetry performed at scan rates from 2.5 to 100 mV s −1 and galvanostatic charge–discharge (GCD) at 0.5–8 A g −1 further supported the enhanced pseudocapacitive behavior of CHY. Electrochemical impedance spectroscopy (EIS) revealed a much lower charge‐transfer resistance for CHY compared to COX, indicating faster electron transport. The results confirm that the topotactic transformation preserves morphology and improves structural stability, although it reduces ion diffusion and available active surface area, resulting in lower capacitance in the oxide phase.
