Recent advances in the synthesis of ZnO-based electrochemical sensors (original) (raw)

ZnO-nanostructure-based electrochemical sensor: Effect of nanostructure morphology on the sensing of heavy metal ions

Beilstein Journal of Nanotechnology, 2018

ZnO nanostructures are promising candidates for use in sensors, especially in electrochemical sensors and biosensors, due to their unique physical and chemical properties, as well as sensitivity and selectivity to several types of contamination, including heavy metal ions. In this work, using the hydrothermal method, nanostructures of ZnO were synthesized in four different morphologies: nanorods, nanoneedles, nanotubes and nanoplates. To determine the peculiarities of adsorption for each morphology, a series of electrochemical measurements were carried out using these nanostructured ZnO coatings on the working electrodes, using aqueous solutions of Pb(NO3)2 and Cd(NO3)2 as analytes with different concentrations. It was found that the sensitivity of the resulting electrochemical sensors depends on the morphology of the ZnO nanostructures: the best results were achieved in the case of porous nanostructures (nanotubes and nanoplates), whereas the lowest sensitivity corresponded to ZnO ...

Chemical Sensing Applications of ZnO Nanomaterials

Materials (Basel, Switzerland), 2018

Recent advancement in nanoscience and nanotechnology has witnessed numerous triumphs of zinc oxide (ZnO) nanomaterials due to their various exotic and multifunctional properties and wide applications. As a remarkable and functional material, ZnO has attracted extensive scientific and technological attention, as it combines different properties such as high specific surface area, biocompatibility, electrochemical activities, chemical and photochemical stability, high-electron communicating features, non-toxicity, ease of syntheses, and so on. Because of its various interesting properties, ZnO nanomaterials have been used for various applications ranging from electronics to optoelectronics, sensing to biomedical and environmental applications. Further, due to the high electrochemical activities and electron communication features, ZnO nanomaterials are considered as excellent candidates for electrochemical sensors. The present review meticulously introduces the current advancements of...

A Highly-Sensitive Picric Acid Chemical Sensor Based on ZnO Nanopeanuts

Materials (Basel, Switzerland), 2017

Herein, we report a facile synthesis, characterization, and electrochemical sensing application of ZnO nanopeanuts synthesized by a simple aqueous solution process and characterized by various techniques in order to confirm the compositional, morphological, structural, crystalline phase, and optical properties of the synthesized material. The detailed characterizations revealed that the synthesized material possesses a peanut-shaped morphology, dense growth, and a wurtzite hexagonal phase along with good crystal and optical properties. Further, to ascertain the useful properties of the synthesized ZnO nanopeanut as an excellent electron mediator, electrochemical sensors were fabricated based on the form of a screen printed electrode (SPE). Electrochemical and current-voltage characteristics were studied for the determination of picric acid sensing characteristics. The electrochemical sensor fabricated based on the SPE technique exhibited a reproducible and reliable sensitivity of ~1...

Synthesis And Characterization Of Nanostructured Zinc Oxide (Zno) For Sensor Applications

2013

This project focuses on the development of new approach to grow a variety of high quality ZnO nanostructures without catalyst through a low cost method by wet thermal evaporation for sensor applications. The growth of ZnO nano- and microstructures is by wet oxidation of Zn powder via the vapour–solid (VS) mechanism. In the first part of this work, the effect of different temperatures on synthesizing high quality ZnO nanostructures on Si/SiO2 substrate was studied. The growth temperatures could be divided into three regions: low (550-650˚C), moderate (700-800˚C), and high (850-900˚C), respectively. The fabrication of high quality ZnO nanostructures for sensor applications was confined in the moderate to high temperature regions. The influence of different durations on the growth of ZnO nanorods was also discussed. Apart from that, a novel fabrication of 3D ZnO microstructures and nanostructures at different temperatures in one step without catalyst was presented. The structural and o...