Hidayat Ullah Shah

Synthesis and ethanol sensing properties of novel hierarchical Sn 3 O 4 nanoflowers

Due to the metastable property and arduous preparation, to control the size and shape of intermediate Sn3O4 nanocrystals to tune functional properties still poses great challenge, and the physical and chemical properties are not fully investigated. Here, we report a simple one-pot template-free hydrothermal route to fabricate Sn3O4 flower-like hierarchical structures self-assembled by aligned high-density nanoslices. In order to explore the growth mechanism, a series of samples with various hydrothermal time were prepared and examined by FESEM and Raman. Results show that the hydrothermal time influences the phases and morphology of the final products. Particularly, a sensor based on these Sn3O4 was implemented to investigate the potential of Sn3O4 for the ethanol detection, revealing that this material reacts to ethanol in a linear way with high response yet at lower temperature (190°C) than that of the well-known SnO2. Also, this intermediate tin oxide with rational control over dimension and morphology provides new opportunities for practical applications in gas sensing towards other reducing gases.

Electrochemical Properties of Controlled Size Mn3O4 Nanoparticles for Supercapacitor Applications

A simple and controlled strategy has been used to synthesise Mn3O4 nanoparticles (NPs) via hydrothermal method. The Mn3O4 nanoparticles were further applied for supercapacitor electrode materials. The unique squared-shape Mn3O4 nanoparticles exhibited excellent electrochemical performance due to the small size and porous architecture. After electrochemical testing, the Mn3O4 NPs based electrode showed a large specific capacitance (380 F g-1, 1.0 mAcm-2) and good cycling stability (88.6%) of the initial capacitance after 5000 cycles in 1.0 M Na2SO4 solution. These results may provide useful guidelines for materials selection, synthesis, size and configuration designs for the novel energy storage devices based on transitional metal oxides.

Enhanced antimicrobial, anti-oxidant applications of green synthesized AgNPs- an acute chronic toxicity study of phenolic azo dyes & study of materials surface using X-ray photoelectron spectroscopy

The drug resistant bacteria and textile contaminations of water cause different sever health problem throughout the world. To overcome this issue, new environmental benign materials and methods are needed. Plant metabolites directed synthesis of nanoparticles is considered eco-friendly and easy in synthesis. Therefore, it was explicit for the synthesis of AgNPs. The prepared AgNPs were evaluated for antibacterial, antioxidant, photo-catalytic and electrochemical degradation properties as well as toxicity of degradation products on aquatic life. X-Ray Photoelectron Spectroscopy (XPS) has been used for analyzing the surface chemistry of prepared AgNPs. The particle size determines the interaction of nanoparticles with pathogens. Both Gram positive and negative bacteria (Escherichia coli and Staphylococcus areous) are used to determine the anti-microbial potency of the green synthesized AgNPs. The synthesized silver nanoparticles showed significant anti-bacterial applications against B. subtilus and S. aureus. The anti-oxidant applications of AgNPs also studied on comparison with vitamin C. The toxicity of the phenolic Azo dyes (PDA) has been studied against Fish, Daphnia and Green Algae. The electrode potential was studied in the electrochemical redox reaction of hydroxy phenol in aqueous media. Simple electrolyte was used to determine the current efficiency. For the stability of electrode multi cyclic voltammetry was also studied during redox reaction, which showed stability under the potential 0.4 to 0.2 V.

New natural product -an efficient antimicrobial applications of new newly synthesized pyrimidine derivatives by the electrochemical oxidation of hydroxyl phenol in the presence of 2-mercapto-6-(trifluoromethyl) pyrimidine-4-ol as nucleophile

Abstract Some new pyrimidine derivatives have been synthesised by electrochemical oxidation of catechol (1a) in the existence of 2-mercapto-6-(trifluoromethyl) pyrimidine-4-ol (3) as a nucleophile in aqueous solution using Cyclic Voltammetric and Controlled Potential Coulometry. The catechol has been oxidised to o-quinone through electrochemical method and participative in Michael addition reaction, leading to the development of some new pyrimidine derivatives. The products were achieved in good yield with high pureness. The mechanism of the reaction has been conformed from the Cyclic Voltammetric data and Controlled Potential Coulometry. After purification, the compounds were characterised using modern techniques. The synthesised materials were screened for antimicrobial actions using Gram positive and Gram negative strain of bacteria. These new synthesised pyrimidine derivatives showed very good antimicrobial activity.