This work demonstrates the applicability of one-dimensional nitrogen-doped diamond nanorods (N-DNRs) for the simultaneous electrochemical (EC) detection of Pb2+ and Cd2+ ions in an electrolyte solution. Well separated voltammetric peaks are observed for Pb2+ and Cd2+ ions using N-DNRs as a working electrode in square wave anodic stripping voltammetry measurements. Moreover, the cyclic voltammetry response of N-DNR electrodes towards the Fe(CN)6 /4-/Fe(CN)6 /3- redox reaction is better as compared to undoped DNR electrodes. This enhancement of EC performance in N-DNR electrodes is accounted by the increased amount of sp2 bonded nanographitic phases, enhancing the electrical conductivity at the grain boundary (GB) regions. These findings are supported by transmission electron microscopy and electron energy loss spectroscopy studies. Consequently, the GB defect induced N-DNRs exhibit better adsorption of metal ions, which makes such samples promising candidates for next generation EC sensing devices. © 2018 Elsevier Ltd

Susanta Sinha Roy

Physics

(SoNS) School of Natural Sciences

Deshmukh S.

Sankaran K.J.

Korneychuk S.

Verbeeck J.

Mclaughlin J.

Haenen K.

Fulltext

<p>Shiv Nadar University is a comprehensive, multidisciplinary, research-focused, and student-centric University offering a full range of academic programs at the undergraduate, postgraduate and doctoral level. With state-of-the-art infrastructure, the University comprises of academic wings, sophisticated labs, international standard sports facilities, amphitheaters, auditorium, conference rooms and smart classrooms. The University&rsquo;s goal is to become internationally recognized for the quality of its research and creative endeavors and their applicability to improving quality of life, generating new insights and expanding the boundaries of human knowledge creativity. Committed to excellence in teaching, research and service, the University aims to serve the higher education needs of India and the world beyond.</p>

Shiv Nadar University

Electrochimica Acta

The possibilities of precise control over the wetting characteristics of carbon-based hybrid nanostructures consisting of both sp2 and sp3 hybridized carbons using the electrowetting technique were demonstrated. An excellent polarity-dependent electrowetting behavior in the presence of an electrolyte followed an abrupt transition from the highly hydrophobic (contact angle ∼ 142°) Cassie-Baxter states to a hydrophilic (∼30°) Wenzel state, where diamond films acted as the anode. In addition, we also reported a remarkable transition from weakly hydrophobic to nearly superhydrophobic diamond nanostructures by chemical and morphological manipulations. The unique structural properties with precisely tailored morphology and surface roughness enabled such transitions on the nanostructured surface. This approach of preparing environmental stable hydrophobic surfaces with polarity-dependent wetting and precise control of the wetting mode transition could be used in numerous applications such as the electrochemical transport of liquids, supercapacitors, and low-friction microfluidics. © 2019 The Royal Society of Chemistry.

Journal of Materials Chemistry A

Direct synthesis of electrowettable nanostructured hybrid diamond

A detailed conductive atomic force microscopic investigation is carried out to directly image the electron emission behavior for nitrogen-doped diamond nanorods (N-DNRs). Localized emission measurements illustrate uniform distribution of high-density electron emission sites from N-DNRs. Emission sites coupled to nanographitic phases at the grain boundaries facilitate electron transport and thereby enhance field electron emission from N-DNRs, resulting in a device operation at low turn-on fields of 6.23 V/μm, a high current density of 1.94 mA/cm2 (at an applied field of 11.8 V/μm) and a large field enhancement factor of 3320 with a long life-time stability of 980 min. Moreover, using N-DNRs as cathodes, a microplasma device that can ignite a plasma at a low threshold field of 390 V/mm achieving a high plasma illumination current density of 3.95 mA/cm2 at an applied voltage of 550 V and a plasma life-time stability for a duration of 433 min was demonstrated. © 2018 Elsevier B.V.

Diamond and Related Materials

Local probing of the enhanced field electron emission of vertically aligned nitrogen-doped diamond nanorods and their plasma illumination properties

One-dimensional diamond nanorods (DNRs) were fabricated from nanocrystalline diamond films using a facile combination of microwave plasma enhanced chemical vapor deposition and reactive ion etching (RIE) techniques. Structural and electrochemical properties of undoped and nitrogen doped DNRs were thoroughly investigated. A cyclic voltammetry study revealed the increase in density of charge carriers when doped with nitrogen. Mott Schottky analysis was implemented for the quantitative determination of the flat band potential, effective density of charge carriers and energy band diagram, which revealed that the undoped sample exhibit p-type behavior, whereas the nitrogen doped sample showed n-type behavior. Defect related damage due to graphitization and hydrogen termination in the undoped DNRs (during RIE) was correlated with the p-type conductivity. Nitrogen doping induces n-type conductivity and enhances effective density of charge carriers. © 2017 Elsevier Ltd

Probing the flat band potential and effective electronic carrier density in vertically aligned nitrogen doped diamond nanorods via electrochemical method

<p>This work describes a simple wet chemical synthesis of iron oxide (Fe3O4) nanoparticles (NPs) capped with terephthalic acid (TA) and their application for the individual detection of Hg(II), Pb(II) and Cd(II) ions as well as simultaneous and selective detection of Hg(II), Pb(II) and Cd(II) ions by electrochemical approach. Terephthalic acid capped Fe3O4 NPs were first characterized by cyclic voltammetry (CV) using redox couples Fe(CN)63&nbsp;−/4&nbsp;−, thereafter square wave anodic stripping voltammetry (SWASV) was utilized for the detection of Hg(II), Pb(II) and Cd(II) ions. Optimization of experimental parameters such as deposition time, deposition potential and pH value of the electrolyte towards electrochemical detection of target heavy metal ions was also carried out in SWASV method. Under optimized experimental conditions limit of detection (LOD) values for individual analysis of Hg(II), Pb(II) and Cd(II) ions were found to be 0.1, 0.05&nbsp;μM and 0.01&nbsp;μM respectively, whereas the LOD values for the simultaneous analysis of Hg(II), Pb(II) and Cd(II) ions were found to be 0.3&nbsp;μM, 0.04&nbsp;μM and 0.2&nbsp;μM respectively. © 2017 Elsevier B.V.</p>

Journal of Electroanalytical Chemistry

Terephthalic acid capped iron oxide nanoparticles for sensitive electrochemical detection of heavy metal ions in water

Biosensors and Bioelectronics

Application of antibody–nanogold–ionic liquid–carbon paste electrode for sensitive electrochemical immunoassay of thyroid-stimulating hormone

Sensors and Actuators B: Chemical

Simultaneous stripping determination of cadmium and lead ions based on the N-doped carbon quantum dots-graphene oxide hybrid

Nanostructured nitrogen doped diamond for the detection of toxic metal ions