Oxidation of alkylarenes by modified graphite

Oxidation of alkylarenes by modified graphit

An aluminum/cobalt/iron/nickel alloy as a precatalyst for water oxidation

Among different strategies, water splitting toward hydrogen production is a promising process to store energy from intermittent sources. However, the anodic water oxidation is a bottleneck for water splitting. In this paper, we report an aluminum/cobalt/iron/nickel alloy as a precatalyst for the electrochemical water oxidation. The alloy electrode contains different metal ions including cobalt, iron, and nickel which all are efficient for water oxidation is tested. We characterized this electrode using scanning electron microscopy, transmission electron microscopy, diffuse reflectance infrared Fourier transform spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy and electrochemical methods. After stabilization, the electrode shows an onset overpotential of 200.0 mV and affords a current density of 3.5 mA cm(-2) at an overpotential of 600.0 mV in KOH solution at pH 13. (C) 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved

An aluminum/cobalt/iron/nickel alloy as a precatalyst for water oxidation

Among different strategies, water splitting toward hydrogen production is a promising process to store energy from intermittent sources. However, the anodic water oxidation is a bottleneck for water splitting. In this paper, we report an aluminum/cobalt/iron/nickel alloy as a precatalyst for the electrochemical water oxidation. The alloy electrode contains different metal ions including cobalt, iron, and nickel which all are efficient for water oxidation is tested. We characterized this electrode using scanning electron microscopy, transmission electron microscopy, diffuse reflectance infrared Fourier transform spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy and electrochemical methods. After stabilization, the electrode shows an onset overpotential of 200.0 mV and affords a current density of 3.5 mA cm(-2) at an overpotential of 600.0 mV in KOH solution at pH 13. (C) 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved

Rethink about electrolyte: Potassium fluoride as a promising additive to an electrolyte for the water oxidation by a nanolayered Mn oxide

Water oxidation is a bottleneck of the hydrogen production through the water-splitting reaction. Herein, the promising role of fluoride on the water-oxidizing activity of a nano layered Mn oxide under the electrochemical condition is reported. The experiments show the increase of the water-oxidizing activity of the nanolayered Mn oxide under an electro-water oxidation circumstance in the presence of potassium fluoride as a promising additive to an electrolyte. As a result, the required overpotential is decreased and the yield of oxygen evolution raised in the water-oxidation reaction. (C) 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved

Biohybrid solar cells: Fundamentals, progress, and challenges

Over the last two decades many reports have been published on diverse types of biohybrid electrodes utilizing components of the photosynthetic apparatus. Currently, the development of such devices does not extend beyond laboratory research. In the future, these electrodes could be used in biosensors, solar cells, and as a new technique to investigate photosynthetic pigment-protein complexes. Efficiency of light-to-current conversion is particularly important for solar cell applications. Selection of a suitable substrate for special pigment-protein complexes is a significant challenge for building an inexpensive and efficient device. Various combinations of pigment-protein complexes and substrates, as well as different measurement conditions make it difficult to directly compare performance of various solar cells. However, it has been shown, that one of the possible substrate materials, namely nanostructured TiO2, is the most preferred material for the immobilization of pigment-protein complexes in terms of both cost and efficiency. The photocurrent values reaching several mA, were reported for TiO2-based biohybrid electrodes. However, the efficiency of TiO2-based biohybrid is still far from its potential maximum value due to fundamental challenges related to designing an optimum interface between TiO2 nanostructure and pigment-protein complexes containing electron transferring cofactors. To date, counterproductive back reactions, also referred to as charge recombination, still dominate and lower internal quantum efficiency of these systems. (C) 2018 Elsevier B.V. All rights reserved

Influence of osmolytes on the stability of thylakoid-based dye-sensitized solar cells

In recent years, there has been considerable interest in incorporating naturally occurring components of the photosynthetic apparatus into man-made solar cells, because of the high quantum efficiency of photosynthetic reaction centers. One hurdle to overcome regarding the use of native membranes in these devices is their limited lifespans. In this study, we used stabilizers to increase the long-term viability of biomolecules in vitro, thereby alleviating this challenge. In this regard, it is known that osmolytes, such as glycine betaine (GB) and sucrose, preserve photosynthetic activity in isolated photosystems. Upon investigation of the thermal protection properties of GB and sucrose in thylakoid-based dye-sensitized solar cells, we report that the addition of GB and sucrose to the thylakoid photosensitizer maintains nonzero photocurrent in the thylakoid-based solar cell upon heating to 50 degrees C. At 50 degrees C, the GB-containing cell displayed about a fourfold increase in photocurrent than the control cell, in which the photocurrent was decreased to nearly zero. The addition of 0.5M and 1M sucrose has respectively caused nearly 40% and 70% increases in photoinduced electron transfer activity over the control at 35 degrees C. Similarly, though to a lesser extent, 1M GB caused an approximate 40% increase in electron transfer activity as well. Moving forward, this approach will be extended to alternative membrane protein isolation strategies, allowing for an accurate comparison with traditional detergent-isolated complexes, with the ultimate goal of developing a cost-effective and sustainable solar cell