Mashkoor Ahmad

Bio: Mashkoor Ahmad is an academic researcher from Pakistan Institute of Nuclear Science and Technology. The author has contributed to research in topics: Electrode & Chemistry. The author has an hindex of 25, co-authored 67 publications receiving 2586 citations. Previous affiliations of Mashkoor Ahmad include University of Science and Technology Beijing & Pakistan Institute of Engineering and Applied Sciences.

Synthesis of hierarchical flower-like ZnO nanostructures and their functionalization by Au nanoparticles for improved photocatalytic and high performance Li-ion battery anodes

Abstract: In this article, hierarchical flower-like ZnO nanostructures with controlled morphology and dimensions have been synthesized by solution phase approach and functionalized by Au nanoparticles (AuNPs) with the combination of electrodeposition to explore novel applications. The photocatalytic activity and lithium storage capacity of these hybrid nanostructures have been investigated. It has been found that hybrid nanostructure combining the large specific surface area, stability and catalytic activity of small AuNPs, demonstrate the higher photocatalytic activity than that of pure ZnO. Furthermore, an initial discharge capacity of 1280 mA h g−1 and a reversible capacity over 392 mA h g−1 at the 50 cycles are achieved for the Au–ZnO hybrid nanostructure, which is found to be much better than that of any previously reported ZnO anodes. The improved lithium storage capacity and cycle life of the Au–ZnO electrode result from the Li activity of Au–ZnO phase. The photocatalytic and electrochemical activity of Au–ZnO hybrid nanostructures provide a new platform for energy storage, environmental remediation and photocatalysis applications.

A Single ZnO Nanofiber-Based Highly Sensitive Amperometric Glucose Biosensor

Abstract: A novel fabrication approach of a highly sensitive amperometric glucose biosensor based on a single ZnO nanofiber (ZONF) is presented. Nanofibers (NFs) of poly(vinyl pyrrolidone)/zinc acetate composite have been synthesized by electrospinning technique. By high-temperature calcinations of the above precursor fibers, ZONFs with diameters in the range of 350−195 nm have been successfully obtained. A single NF on a gold electrode is functionalized with glucose oxidase (GOx) by physical adsorption. Electrochemical measurements of the biosensor revealed a high and reproducible sensitivity of 70.2 μA cm−2 mM−1 within a response time of less than 4 s. The biosensor also showed a linear range from 0.25 to 19 mM with a low limit of detection (LOD) of 1 μM. Furthermore, it has been revealed that the biosensor exhibits a good anti-interference ability and favorable stability over relatively long-term storage (more than 4 months). All these results strongly suggest that a single ZONF can provide a new platform for bi...

ZnO based advanced functional nanostructures: synthesis, properties and applications

Abstract: ZnO nanostructures, due to their novel properties, are promising components in a wide range of nanoscale devices for future applications. This article provides a comprehensive review of the current research activities that focus on the synthesis, characterization and applications of ZnO based nanostructures. We briefly describe the most commonly applied methodologies for the synthesis of ZnO nanostructures. A range of remarkable characteristics is then presented, organized into sections describing the optical, electrical and mechanical properties. Finally, we include a brief analysis of the possible future trends for the application of this interesting semiconductor oxide for hydrogen storage and biosensors. These studies constitute the basis for developing versatile applications of ZnO nanostructures.

Highly Sensitive Amperometric Cholesterol Biosensor Based on Pt-Incorporated Fullerene-like ZnO Nanospheres

Abstract: A highly sensitive amperometric biosensor based on Pt-incorporated fullerene-like ZnO hybrid nanospheres has been investigated. Pt−ZnO nanospheres (PtZONS) with diameters in the range 50−200 nm have been successfully synthesized by electrodeposition on a glassy carbon electrode (GCE). The Pt nanoparticles in ZnO nanospheres have been identified with high-resolution transmission electron microscopy (HRTEM) and energy dispersive X-ray spectroscopy (EDS). The doped Pt nanoparticles demonstrate the abilities to electrocatalyze the oxidation of hydrogen peroxide and substantially raise the response current. The sensitivity of the PtZONS/GCE to hydrogen peroxide is 147.8 μA μM−1 cm−2, which is much higher than that of a conventional electrode. The PtZONS/GCE was functionalized with cholesterol oxidase (ChOx) by physical adsorption. The enzyme electrode exhibits a very high and reproducible sensitivity of 1886.4 mA M−1 cm−2 to cholesterol with a response time less than 5 s and a linear range from 0.5 to 15 μM. F...

Zinc Oxide-From Synthesis to Application: A Review.

Abstract: Zinc oxide can be called a multifunctional material thanks to its unique physical and chemical properties. The first part of this paper presents the most important methods of preparation of ZnO divided into metallurgical and chemical methods. The mechanochemical process, controlled precipitation, sol-gel method, solvothermal and hydrothermal method, method using emulsion and microemulsion enviroment and other methods of obtaining zinc oxide were classified as chemical methods. In the next part of this review, the modification methods of ZnO were characterized. The modification with organic (carboxylic acid, silanes) and inroganic (metal oxides) compounds, and polymer matrices were mainly described. Finally, we present possible applications in various branches of industry: rubber, pharmaceutical, cosmetics, textile, electronic and electrotechnology, photocatalysis were introduced. This review provides useful information for specialist dealings with zinc oxide.

Complex Hydrides for Hydrogen Storage

Abstract: Note: Times Cited: 875 Reference EPFL-ARTICLE-206025doi:10.1021/cr0501846View record in Web of Science URL: ://WOS:000249839900009 Record created on 2015-03-03, modified on 2017-05-12

High-Power Lithium Batteries from Functionalized Carbon Nanotube Electrodes

Abstract: Energy storage devices that can deliver high powers have many applications, including hybrid vehicles and renewable energy. Much research has focused on increasing the power output of lithium batteries by reducing lithium-ion diffusion distances, but outputs remain far below those of electrochemical capacitors and below the levels required for many applications. Here, we report an alternative approach based on the redox reactions of functional groups on the surfaces of carbon nanotubes. Layer-by-layer techniques are used to assemble an electrode that consists of additive-free, densely packed and functionalized multiwalled carbon nanotubes. The electrode, which is several micrometres thick, can store lithium up to a reversible gravimetric capacity of approximately 200 mA h g(-1)(electrode) while also delivering 100 kW kg(electrode)(-1) of power and providing lifetimes in excess of thousands of cycles, both of which are comparable to electrochemical capacitor electrodes. A device using the nanotube electrode as the positive electrode and lithium titanium oxide as a negative electrode had a gravimetric energy approximately 5 times higher than conventional electrochemical capacitors and power delivery approximately 10 times higher than conventional lithium-ion batteries.

Nanotechnology-Enabled Energy Harvesting for Self-Powered Micro-/Nanosystems

Abstract: Health, infrastructure, and environmental monitoring as well as networking and defense technologies are only some of the potential areas of application of micro-/nanosystems (MNSs). It is highly desirable that these MNSs operate without an external electricity source and instead draw the energy they require from the environment in which they are used. This Review covers various approaches for energy harvesting to meet the future demand for self-powered MNSs.