Oxygen evolution at ultrathin nanostructured Ni(OH)2 layers deposited on conducting glass

Ultrathin and transparent nanostructured Ni(OH)2 films were deposited on conducting glass (F:SnO2) by a urea-based chemical bath deposition method. By controlling the deposition time, the amount of deposited Ni(OH)2 was varied over 7 orders of magnitude. The turnover number for O2 generation, defined as the number of O2 molecules generated per catalytic site (Ni atom) and per second, increases drastically as the electrocatalyst amount decreases. The electrocatalytic activity of the studied samples (measured as the current density at a certain potential) increases with the amount of deposited Ni(OH)2 until a saturation value is already obtained for a thin film of around 1 nm in thickness, composed of Ni(OH)2 nanoplatelets lying flat on the conductive support. The deposition of additional amounts of catalyst generates a porous honeycomb structure that does not improve (only maintains) the electrocatalytic activity. The optimized ultrathin electrodes show a remarkable stability, which indicates that the preparation of highly transparent electrodes, efficient for oxygen evolution, with a minimum amount of nickel is possible.

Potentiostatic Reversible Photoelectrochromism: An Effect Appearing in Nanoporous TiO2/Ni(OH)2 Thin Films

In the field of energy saving, finding composite materials with the ability of coloring upon both illumination and change of the applied electrode potential keeps on being an important goal. In this context, chemical bath deposition of Ni(OH)2 into nanoporous TiO2 thin films supported on conducting glass leads to electrodes showing both conventional electrochromic behavior (from colorless to dark brown and vice versa) together with photochromism at constant applied potential. The latter phenomenon, reported here for the first time, is characterized by fast and reversible coloration upon UV illumination. The bleaching kinetics shows first order behavior with respect to the NiIII centers in the film, and an order 1.2 with respect to electrons in the TiO2 film. From a more applied point of view, this study opens up the possibility of having two-mode smart windows showing not only conventional electrochromism but also reversible darkening upon illumination.

An Acyl-NHC Osmium Cooperative System: Coordination of Small Molecules and Heterolytic B–H and O–H Bond Activation

The hexahydride complex OsH6(PiPr3)2 (1) activates the C–OMe bond of 1-(2-methoxy-2-oxoethyl)-3-methylimidazolium chloride (2), in addition to promoting the direct metalation of the imidazolium group, to afford a five-coordinate OsCl(acyl-NHC)(PiPr3)2 (3) compound. The latter coordinates carbon monoxide, oxygen, and molecular hydrogen to give the corresponding carbonyl (4), dioxygen (5), and dihydrogen (6) derivatives. Complex 3 also promotes the heterolytic bond activation of pinacolborane (HBpin), using the acyl oxygen atom as a pendant Lewis base. The hydride ligand and the Bpin substituent of the Fischer-type carbene of the resulting complex 7 activate the O–H bond of alcohols and water. As a consequence, complex 3 is a metal ligand cooperating catalyst for the generation of molecular hydrogen, by means of both the alcoholysis and hydrolysis of pinacolborane, via the intermediates 7 and 6.

Kitāb Adab al-kātib fī al-maṣāḥif wa-fīhi ʻadad al-āyāt wa-ḥarfuhā wa-al-ḥurūf fī akhir al-āyāt / li-al-Shaykh ʻAlam al-Dīn al-Sakhāwī : manuscript, 1602

Written in one column, in a nastaʻlīq script in black ink, rubricated in red, 13 lines per page, with marginal corrections. Catchwords on the verso of each leaf.

Juzʼ fīhi thamānūn ḥadīthan ʻan thamānīn shaykhan / taʼlīf al-Shaykh ... Abī Bakr Muḥammad ibn al-Ḥusayn al-Ājurrī : manuscript, [12--?]

Bound with ʻAlī ibn al-Ḥasan ibn ʻAsākir, Kitāb al-Arbaʻīn al-buldānīyah, and other hadith collections.

Juzʼ fīhi Arbaʻūn ḥadīthan / li-Abī Bakr Muḥammad ibn al-Ḥusayn al-Ājurrī : manuscript, [12--?]

Bound with ʻAlī ibn al-Ḥasan ibn ʻAsākir, Kitāb al-Arbaʻīn al-buldānīyah, and other hadith collections.

Juzʻ fīhi ʻAsharat majālis min amālī al-Shaykh al-Ḥāfiẓ Abī Muḥammad al-Ḥasan ibn Muḥammad al-Ḥasan al-Khallāl : manuscript, [12--?]

Bound with ʻAlī ibn al-Ḥasan ibn ʻAsākir, Kitāb al-Arbaʻīn al-buldānīyah, and other hadith collections.

Juzʼ fīhi aḥādīth Abī ʻAbd Allāh al-Ḥusayn ibn Yaḥyá ibn ʻAyyāsh ... al-Tūnī ʻan shuyūkhih : manuscript, [12--?]

Bound with ʻAlī ibn al-Ḥasan ibn ʻAsākir, Kitāb al-Arbaʻīn al-buldānīyah, and other hadith collections.

The Relationship Between Cadwaladerite Al(OH)2Cl∙4H2O and Lesukite Al2(OH)5Cl∙2H2O as Investigated by SEM, PXRD, FTIR and Raman Spectroscopy

Cadwaladerite (Al(OH)2Cl∙4H2O) collected from Cerro Pintados, Chile described by Gordon in 1941 is designated as “doubtful” by the IMA. Material collected from the same locality in 2015 resembling the description of cadwaladerite gave a powder XRD pattern similar to lesukite (Al2(OH)5Cl∙2H2O). However, Gordon provided no X-ray data for his material from Cerro Pintados. In order to determine whether cadwaladerite and lesukite are the same mineral species, measurements were made on a suite of samples from various localities. A portion of the material collected by Gordon in 1941 was also obtained from the Mineralogical Museum of Harvard University. Type material of lesukite from a fumarolic environment at the Tolbachik Fissure in Kamchatka, Russia was obtained as well as lesukite from the Maria Mine, Chile (Arica Province) and a previously undescribed locality for lesukite (Barranaca del Sulfato, Mejillones Peninsula, Antofagasta Province). All samples are yellow to yellow-orange in colour and all exhibit small cubic crystals (up to 50µm), even Gordon’s cadwaladerite which was thought to be amorphous. The Chilean samples are all associated with halite and sometimes with anhydrite. These five samples were studied by SEM, FTIR, powder XRD, and Raman spectroscopy. A ratio of Al:Cl less than or equal to 1.3:1 was observed for all the samples, including measurements made on lesukite from the Russian locality Vergasova et al. studied in 1997, and determined to have a 2:1 ratio. SEM-EDS analyses also show all samples to have minor iron substitution, as well as copper substitution in two samples. FTIR spectra are very similar for all samples. Raman spectroscopy done on both samples collected in Cerro Pintados and the Russian lesukite gave similar spectra. Powder XRD analyses on all samples showed spectra identified to be lesukite, including Gordon’s cadwaladerite. Crystal cell parameters calculated from powder XRD ranged from 19.778Å to 19.878Å. Results using modern instrumental techniques confirm Gordon’s cadwaladerite, collected in 1939 and described in 1941, and lesukite are the same mineral species.

The Ghost of Deflation Past. CEPS Hi-level Brief, 13 December 2013

This note takes a look at the development of monetary aggregates and debt in the G7 (US, UK, France, Germany, Italy, Canada and Japan), plus non-G7 euro-area countries, which have an important bearing on the future development of price levels. It also discusses the problem of restoring external competitiveness in the weaker euro-area countries without aggravating their debt burden. The key conclusions are i) monetary and debt developments in the G7 countries point to relatively sluggish growth but do not signal deflation risks and ii) the realignment of ‘internal real exchange rates’ in the euro area will most likely come through a rise in prices in Germany (and a few other stronger countries). The lessons learned in the early 1930s have made a come-back of deflation quite unlikely.

Larry Summers’ interest rate conundrum. CEPS Hi-level Brief, 16 January 2014

Larry Summers has attracted much attention recently for invoking old theories of secular stagnation to explain the persistence of low interest rates in the recent past. The German economist Carl Christian von Weizsäcker has pointed to a retirement savings glut as the cause for low rates. In the view of Thomas Mayer, however, as expressed in this High-Level Brief, these theses lack both theoretical and empirical support and he offers as an alternative explanation the fall-out from the recent credit boom-bust cycle.

Latvia and Greece: Less is more. CEPS Hi-level Brief, 12 February 2014

Despite considerable differences, there were also many similarities in economic performance between Latvia and Greece before their respective adjustment crises. After the immediate crisis, however, economic activity rebounded sharply in Latvia but continued to contract in Greece. This paper argues that this difference was due primarily to developments in credit. In Latvia credit growth fell sharply, and the economy was deleveraging aggressively by 2009. When the pace of deleveraging started to stabilise, the rebound in the credit impulse caused domestic demand growth to recover. Real GDP has increased about 20% since reaching its trough in the third quarter of 2009.

The Fate of Greece in a ‘Genuine Economic and Monetary Union’: Lessons from a small island state. CEPS Hi-Level Brief, 19 June 2015 Friday, 19 June 2015

As the Greek debt drama reaches another supposedly decision point, Daniel Gros urges creditors (and indeed all policy-makers) to think about the long term and poses one key question in this CEPS High-Level Brief: What can be gained by keeping Greece inside the euro area at “whatever it takes”? As he points out, the US, with its unified politics and its federal fiscal transfer system, is often taken as a model for the Eurozone, and it is thus instructive to consider the longer-term performance of an area of the US which has for years been kept afloat by massive transfers, and which is now experiencing a public debt crisis. The entity in question is Puerto Rico, which is an integral part of the US in all relevant economic dimensions (currency, economic policy, etc.). The dismal fiscal and economic performance of Puerto Rico carries two lessons: 1) Keeping Greece in the eurozone by increasing implicit subsidies in the form of debt forgiveness might create a low-growth equilibrium with increasing aid dependency. 2) It is wrong to assume that, further integration, including a fiscal and political union, would be sufficient to foster convergence, and prevent further problems of the type the EU is experiencing with Greece.