Phosphorene (few layer black phosphorus) has the potential to be an efficient catalyst for H 2 evolution from water splitting reaction. This perspective highlights functionalized phosphorenes and explores their use in catalytic H 2 production.
Melting temperatures of alkali halides have been calculated assuming that different structures of an ionic solid exhibiting polymorphism will have nearly identical energy around the melting point: the calculated value for CsCl shows good agreement with the observed value.
Normal vibration analysis of cyclic tetraglycine has been carried out employing the Urey‐Bradley force field and the vibrational assignments are compared with those in related molecules.
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTA study of strong metal-support interaction based on an electron spectroscopic investigation of nitrogen adsorption on simulated nickel/titania, nickel/alumina and related catalyst surfacesG. Ranga. Rao and C. N. R. RaoCite this: J. Phys. Chem. 1990, 94, 20, 7986–7991Publication Date (Print):October 1, 1990Publication History Published online1 May 2002Published inissue 1 October 1990https://doi.org/10.1021/j100383a043Request reuse permissionsArticle Views115Altmetric-Citations13LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (670 KB) Get e-Alerts
The Coulomb staircase in polymer-covered Pd and Au nanocrystals of varying diameters in the 1.7–6.4 nm has been investigated by employing tunneling conductance measurements. Charging up to several electrons is observed at room temperature in the I–V data. Small nanocrystals show charging steps exceeding 200 mV while the larger ones exhibit smaller steps. Significantly, the charging energies follow a scaling law of the form, U=A+B/d, where d is the diameter of the nanocrystal. Furthermore, the line widths in the derivative spectra also vary inversely with the diameter.
Ab initio molecular orbital calculations show that the dimer of HO2 may possess a symmetric cyclic hydrogen bonded structure. Energy changes accompanying a number of reactions of HO2 of interest in atmospheric chemistry have been evaluated. H2O3 is shown to be stable with respect to HO2 and OH radicals. Ionization of HO2 to O2 − as well as the reaction of HO2 with O2 − and ethylene have been examined. HO3 and O2 − are shown to form stable hydrogen bonded complexes with H2O.
No abstract is provided for this article.
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
The structure-activity relationship in the electrochemical OER has been studied widely, but aspects of the photoelectrochemical (PEC) O2 evolution activity with different manganese oxides are not fully explored. In the present study different manganese oxides (MnO2, MnOx (a mixture of Mn3+ and Mn4+ ions), Mn2O3, and Mn3O4) have been electrodeposited onto the BiVO4 photoanode as co-catalysts for PEC water splitting. We find that BiVO4-MnOx shows the lowest onset potential of 0.33 V vs. RHE and the highest activity among the manganese oxides. Annealing at different temperatures results in the improvement of the OER kinetics at the interface with some detrimental effect on the activity of BiVO4. Such a study may lead to useful changes in the fabrication of semiconductor thin film photoelectrodes useful for PEC water splitting.
Macroporous carbons of different pore sizes, containing three-dimensionally connected voids, have been prepared by an elegant method. The method involves the coating of ordered silica spheres with sucrose, followed by carbonization using sulfuric acid, and the removal of silica with aqueous hydrofluoric acid. The carbon samples show the expected optical properties. The surface area of the macroporous carbon samples varies between 120 to 550 m2g−1, depending on whether nonporous or mesoporous silica spheres were used as templates.
The In My Element series celebrates the personal accounts from Chemistry – A European Journal Editorial Board members for the 2019 International Year of the Periodic Table. In this contribution, C. N. R. Rao gives his story on oxygen. My love for oxygen can be traced to the very beginning of my research career. This is not because oxygen was discovered by the Father of Chemistry, Lavoisier, and it is essential for life as O2 and as H2O, but because it forms a variety of metal oxides with interesting structures and a wide range of properties1 (Table 1). Oxygen can exist as O21−, O22− and O2− in solids and as O1− on certain surfaces. Oxygen stoichiometry is an important aspect of oxides, oxygen deficiency often giving rise to new types of ordered structures (TinO2n−1 Magneli phases, Pr2O2n−2). Metallic: ReO3, NbO, LaNiO3 Dielectric: BaTiO3 Antiferromagnetic: NiO, LaCrO3 Ferromagnetic: CrO2, La0.5Sr0.5CoO3, SrRuO3 Ferroelectric: BaTiO3, KNbO3 Ferroelastic: Gd2(MoO4)3 Superconducting: BaPb0.75Bi0.25O3, YBa2Cu3O7 Insulator-Metal Transition: V2O3, VO2, La1−xSrxCoO3 Colossal Magnetoresistance (CMR): La0.7Ca0.3MnO3 Multiferroic: BiFeO3, YMnO3, TbMnO3 I have worked on metal oxides for a long time,2 and my very first research paper in materials chemistry in the late 1950′s was on the transformation of the anatase form of TiO2 to the rutile form. I also studied the so-called nonstoichiometric oxides of rare earths of the type Pr6O11, Pr7O12 and Tb4O7. Soon I realized how perovskite oxides (ABO3) exhibit a variety of phenomena and properties such as ferroelectricity and magnetism, and how the pervoskite motif is present in several families of oxides. I have been working on perovskite oxides including two-dimensional oxides for many years. I worked on La2CuO4, as early as 1971, mother of cuprate superconductors. My group was one of the first to characterize YBa2Cu3O7, the first liquid nitrogen superconductor, which also has the perovskite motif. The number of cuprate families exhibiting high temperature superconductivity is impressive.3 The discovery of colossal magnetoresistance in rare earth manganites of the type La1−xCaxMnO3 which show both orbital and charge-ordering led to a variety of investigations and to the observation of the phenomenon of electronic phase separation.4 We observed major effects of phase separation in Nd0.5Sr0.5MnO3, which is ferromagnetic at ordinary temperatures, and occurs in three phases (FM+2AFMs) at liquid helium temperatures. I started working on multiferroics in the 1990’s, the well-known examples being BiFeO3 and YMnO3. Cation substitution in oxides is commonly carried out to cause changes in structures and properties. An impressive example is that of Sr substituted LaCoO3 where a paramagnetic insulator becomes a ferromagnetic metal on substitution of Sr in place of La. Cation substitution generally affects the unoccupied states and anion substitution, specially aliovalent anions on the other hand, cause drastic changes in the valence bands. In recent months, I have been working on oxide analogues wherein oxygen is substituted by nitrogen and fluorine, resulting is novel electronic and catalytic properties.5 For example, Zn2NF and TiNF are isoelectronic with ZnO and TiO2 respectively, but exhibit entirely different electronic structures and properties. Position Linus Pauling Research Professor E-mail [email protected] Homepage http://www.jncasr.ac.in/cnrrao Education B.Sc (Mysore, 1951), M.Sc (Banaras, 1953) Ph.D (1957, Prof R.L. Livingston, Purdue, “Molecular structure investigations by gas phase electron diffraction)” D.Sc (1960) Mysore “Studies of Structural Chemistry and Nitrogen Chemistry” Post-doctoral fellowship (1958-1959; Berkeley, Prof K.S. Pitzer) Awards Dan David Prize for Science in the Future Dimension (2005) Ernesto Illy Trieste Science Prize (2011) for materials research The Royal Medal (The Queens Medal) of the Royal Society, London, U.K (2009) The August-Wilhelm-von-Hoffmann Medal for outstanding contributions to chemistry by the German Chemical Society (2010) Von Hippel Award for materials research by Materials Research Society, US (2017) Chevalier de la Légion D′Honneur by the President of the French Republic (2005) Order of the Rising Sun, Gold and Silver Star by the Emperor of Japan (2015) Bharat Ratna (Jewel of India), Highest Civilian Award of India (2014) Research interests Chemistry of Materials, in particular, oxide materials, 2D materials, solar water-splitting Hobbies and interests Listening to classical music and cooking
