There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

3.6.1. Polishing and Cleaning 2663 3.6.2. Vacuum and Heat Treatments 2664 3.6.3. Carbon Electrode Activation 2665 3.7. Summary and Generalizations 2666 4. Advanced Carbon Electrode Materials 2666 4.1. Microfabricated Carbon Thin Films 2666 4.2. Boron-Doped Diamond for Electrochemistry 2668 4.3. Fibers and Nanotubes 2669 4.4. Carbon Composite Electrodes 2674 5. Carbon Surface Modification 2675 5.1. Diazonium Ion Reduction 2675 5.2. Thermal and Photochemical Modifications 2679 5.3. Amine and Carboxylate Oxidation 2680 5.4. Modification by “Click” Chemistry 2681 6. Synopsis and Outlook 2681 7. Acknowledgments 2682 8. References 2682

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Advanced carbon electrode materials for molecular electrochemistry.

Due to the significance of hydrogen peroxide (H(2)O(2)) in biological systems and its practical applications, the development of efficient electrochemical H(2)O(2) sensors holds a special attraction for researchers Various materials such as Prussian blue (PB), heme proteins, carbon nanotubes (CNTs) and transition metals have been applied to the construction of H(2)O(2) sensors In this article, the electrocatalytic H(2)O(2) determinations are mainly focused on because they can provide a superior sensing performance over non-electrocatalytic ones The synergetic effect between nanotechnology and electrochemical H(2)O(2) determination is also highlighted in various aspects In addition, some recent progress for in vivo H(2)O(2) measurements is also presented Finally, the future prospects for more efficient H(2)O(2) sensing are discussed

Recent advances in electrochemical sensing for hydrogen peroxide: a review

We report a novel microwave plasma enhanced chemical vapor deposition strategy for the efficient synthesis of multilayer graphene nanoflake films (MGNFs) on Si substrates The constituent graphene nanoflakes have a highly graphitized knife-edge structure with a 2-3 nm thick sharp edge and show a preferred vertical orientation with respect to the Si substrate as established by near-edge X-ray absorption fine structure spectroscopy The growth rate is approximately 16 mu m min(-1), which is 10 times faster than the previously reported best value The MGNFs are shown to demonstrate fast electron-transfer (ET) kinetics for the Fe(CN)(6)(3-/4-) redox system and excellent electrocatalytic activity for simultaneously determining dopamine (DA), ascorbic acid (AA) and uric acid (UA) Their biosensing DA performance in the presence of common interfering agents AA and UA is superior to other bare solid-state electrodes and is comparable only to that of edge plane pyrolytic graphite Our work here, establishes that the abundance of graphitic edge planes/defects are essentially responsible for the fast ET kinetics, active electrocatalytic and biosensing properties This novel edge-plane-based electrochemical platform with the high surface area and electrocatalytic activity offers great promise for creating a revolutionary new class of nanostructured electrodes for biosensing, biofuel cells and energy-conversion applications

Catalyst-Free Efficient Growth, Orientation and Biosensing Properties of Multilayer Graphene Nanoflake Films with Sharp Edge Planes**

In recent years, nanocrystals of metal sulfide materials have attracted scientific research interest for renewable energy applications due to the abundant choice of materials with easily tunable electronic, optical, physical and chemical properties. Metal sulfides are semiconducting compounds where sulfur is an anion associated with a metal cation; and the metal ions may be in mono-, bi- or multi-form. The diverse range of available metal sulfide materials offers a unique platform to construct a large number of potential materials that demonstrate exotic chemical, physical and electronic phenomena and novel functional properties and applications. To fully exploit the potential of these fascinating materials, scalable methods for the preparation of low-cost metal sulfides, heterostructures, and hybrids of high quality must be developed. This comprehensive review indicates approaches for the controlled fabrication of metal sulfides and subsequently delivers an overview of recent progress in tuning the chemical, physical, optical and nano- and micro-structural properties of metal sulfide nanocrystals using a range of material fabrication methods. For hydrogen energy production, three major approaches are discussed in detail: electrocatalytic hydrogen generation, powder photocatalytic hydrogen generation and photoelectrochemical water splitting. A variety of strategies such as structural tuning, composition control, doping, hybrid structures, heterostructures, defect control, temperature effects and porosity effects on metal sulfide nanocrystals are discussed and how they are exploited to enhance performance and develop future energy materials. From this literature survey, energy conversion currently relies on a limited range of metal sulfides and their composites, and several metal sulfides are immature in terms of their dissolution, photocorrosion and long-term durability in electrolytes during water splitting. Future research directions for innovative metal sulfides should be closely allied to energy and environmental issues, along with their advanced characterization, and developing new classes of metal sulfide materials with well-defined fabrication methods.

Recent advances in metal sulfides: from controlled fabrication to electrocatalytic, photocatalytic and photoelectrochemical water splitting and beyond

Simultaneous determination of dopamine, ascorbic acid, and uric acid using carbon ionic liquid electrode

Direct electrochemistry of hemoglobin and its electrocatalytic effect based on its direct immobilization on carbon ionic liquid electrode

A reliable and simple electrochemical method has been proposed for the simultaneous determination of paracetamol (PAR) and p-aminophenol (PAP) in pharmaceutical formulations. The oxidation and reduction peak potentials in cyclic voltammetry (CV) for PAR on carbon ionic liquid electrode (CILE) were occurred at 370 and 225 mV vs. Ag/AgCl, respectively at pH 7.0, while those for PAP on CILE appeared at 128 mV and 68 mV, respectively at the scan rate of 0.05 V s−1. In comparison to the conventional carbon paste electrode, the apparent reversibility and kinetics of the electrochemical reactions of PAR and PAP were significantly improved on CILE. In differential pulse voltammetric technique, the peak potentials for PAR and PAP appeared at 345 and 130 mV, respectively, with the peak separation of 215 mV, sufficient for their simultaneous determination in samples containing these two species. The proposed method was used for simultaneous determination of PAR and PAP in tablets. PAR and PAP can be determined in the ranges of 2.0×10−6–2.2×10−3 M and 3.0×10−7–1.0×10−3 M, with the detection limits of 5.0×10−7 and 1.0×10−7 M (calculated by 3σ), respectively. The relative standard deviations for the determination of PAR and PAP were less than 2%.

A Selective and Sensitive Method for Simultaneous Determination of Traces of Paracetamol and p-Aminophenol in Pharmaceuticals Using Carbon Ionic Liquid Electrode

Vertically aligned ZnO@CdS nanorod heterostructures for visible light photoinactivation of bacteria

Free-standing TiO2 nanotube array (TNA) films were fabricated via two-step anodization of a titanium sheet. The X-ray diffraction pattern indicated amorphous TNAs were transformed into anatase after annealing the films at 500 °C in air. The surface of TNA was modified by a sequential-chemical bath deposition (S-CBD) method to fabricate Ag2S nanoparticles and forming TNA/Ag2S-n nanostructure, by varying the number of cycles (n). Based on SEM observations, the produced films consisted of vertically ordered tubular structure arrays, each with 125 nm in diameter and 4.1 μm in length containing silver sulphide nanoparticles of ∼12 nm diameter. X-Ray photoelectron spectroscopy (XPS) confirmed the formation of Ag2S nanoparticles on TNA film. Increased optical absorption of the TNA/Ag2S system in visible and near infrared was also verified by diffuse reflectance spectroscopy (DRS). Maximum photocurrent density of about 840 μA cm−2 was measured for the synthesized TNA/Ag2S-4 photoanode under visible irradiation which exhibited about 15 fold photo-enhancement in current density as compared with the pure TNAs under similar conditions. The incident photon to current efficiency (IPCE) measurements indicated that the visible response of the samples reached its maximum value of about 20% at a wavelength of 600 nm for the TNA/Ag2S photoanode.

Omran Moradlou

Papers

Simultaneous determination of dopamine, ascorbic acid, and uric acid using carbon ionic liquid electrode

Direct electrochemistry of hemoglobin and its electrocatalytic effect based on its direct immobilization on carbon ionic liquid electrode

A Selective and Sensitive Method for Simultaneous Determination of Traces of Paracetamol and p-Aminophenol in Pharmaceuticals Using Carbon Ionic Liquid Electrode

Vertically aligned ZnO@CdS nanorod heterostructures for visible light photoinactivation of bacteria

Optimal Ag2S nanoparticle incorporated TiO2 nanotube array for visible water splitting