Kurt Dr. Meier

Bio: Kurt Dr. Meier is an academic researcher from Novartis. The author has contributed to research in topics: Photoinitiator & Epoxy. The author has an hindex of 19, co-authored 53 publications receiving 1524 citations. Previous affiliations of Kurt Dr. Meier include Huntsman Corporation.

Photochemical hydrogen production with cadmium sulfide suspensions

Abstract: Active photocatalysts for photochemical hydrogen production have been prepared by platinum deposition on microcrystals of CdS powders. Hydrogen produced by irradiating suspensions of platinized CdS in various electrolyte solutions (S/sup 2 -/, SO/sub 3//sup 2 -/, H/sub 2/PO/sup 2 -/) has been shown to be significantly improved by photoetching the CdS microcrystals. The efficiency of hydrogen formation in solutions containing S/sup 2 -/ is low due to the formation of disulfide ions. Additional of reducing agents such as sulfite or hypophosphite ions, which efficiently suppresses disulfide formation, allows hydrogen to evolve at a surprisingly high rate. In the case of a solution containing both S/sup 2/ and SO/sub 3//sup 2 -/ ions, the formation of thiosulfate is observed with a quantum yield of 0.25. In mixtures of sulfide and hypophosphite ions, phosphite and phosphate ions are the oxidation products. Hydrogen formation occurs in solutions containing SO/sub 3//sup 2 -/ ions only when the platinized CdS particles have previously been photoetched. Concomitant to the proton reduction, SO/sub 3//sup 2 -/ ions are oxidized to sulfate and dithionate. In 12 days, 9 L of H/sub 2/ was generated by irradiating 1 g of CdS/Pt suspended in an Na/sub 2/SO/sub 3/ solution. Aftermore » this period, the efficiency of the photocatalyst dropped to about 60% of the initial rate. The reaction parameters and the formation of the oxidation products have been investigated in detail. 57 references, 10 figures, 4 tables.« less

Photochemical production of hydrogen with zinc sulfide suspensions

Abstract: Hydrogen has been produced efficiently by the irradiation of suspensions of metalized ZnS powders in the presence of hole scavengers such as S/sup 2 -/ and SO/sub 3//sup 2 -/ions, mixtures of these two, or S/sup 2 -/ and hypophosphite ions. Results of investigation of the properties of active ZnS photocatalysts, the reaction parameters, and the formation of the reaction products are reported. The rate of the reaction was found to be strongly dependent on the amount of ZnS, and ZnS produced 5 times as much hydrogen as CdS.

Curable composition and use thereof

Abstract: Eisen(II)-Aromatenkomplexe in Abmischung mit Elektronenacceptoren als Oxidationsmittel sind geeignete Initiatoren fur die Polymerisation von kationisch und/oder radikalisch polymerisierbarem organischem Material durch Bestrahlung. Iron (II) -Aromatenkomplexe in admixture with electron acceptors as oxidizing agents are suitable initiators for the polymerization of cationically and / or radically polymerizable organic material by irradiation. Die Zusammensetzung aus dem polymerisierbaren Material und der Initiatormischung ist zur Herstellung von Schutzuberzugen geeignet und kann als photographisches Aufzeichnungsmaterial verwendet werden. The composition of the polymerizable material and the initiator mixture is suitable for the production of protective coatings and can be used as a photographic recording material.

Thermally transferable layers of radiation sensitive epoxy resins used to prepare protective coatings and relief images

Abstract: A process for the production of a protective layer or a relief image on a substrate, wherein a radiation-sensitive layer, consisting of a solid film-forming epoxy resin containing a photoinitiator, which can be activated by radiation, for the polyaddition reaction, is transferred from a support to a substrate, then exposed directly or under a photomask and hardened by the action of heat, after which, if appropriate, the unexposed parts are developed with a solvent. The process is suitable, for example, for the production of printed circuits, solder resist masks and offset printing plates.

Curable compositions containing metallocen complexes, activated primers obtained therefrom and their use

Abstract: Die Erfindung betrifft hartbare Zusammensetzungen, die aus The invention relates to curable compositions consisting of A) einem kationisch polymerisierbaren organischen Material und A) a cationically polymerizable organic material and B) mindestens einer Verbindung der Formel B) at least one compound of the formula worin a, m, n, q, R 1 , R 2 , M, L und Q die in Anspruch 1 angegebenen Bedeutungen haben, bestehen. wherein a, m, n, q, R 1, R 2, M, L and Q have the meanings given in claim 1, are made. Diese Zusammensetzungen eignen sich zur Herstellung von Oberflachenbeschichtungen, Druckplatten und insbesondere gedruckten Schaltungen. These compositions are suitable for the preparation of surface coatings, printing plates, and particularly printed circuits. Sie lassen sich direkt heissharten, werden aber vorzugsweise zunachst bestrahlt, was lagerfahige aktivierte Vorstufen ergibt, und dann heissgehartet. They can be hot cured directly, but are preferably first irradiated, resulting storable activated precursors and then hot-cured.

Heterogeneous photocatalyst materials for water splitting

Abstract: This critical review shows the basis of photocatalytic water splitting and experimental points, and surveys heterogeneous photocatalyst materials for water splitting into H2 and O2, and H2 or O2 evolution from an aqueous solution containing a sacrificial reagent Many oxides consisting of metal cations with d0 and d10 configurations, metal (oxy)sulfide and metal (oxy)nitride photocatalysts have been reported, especially during the latest decade The fruitful photocatalyst library gives important information on factors affecting photocatalytic performances and design of new materials Photocatalytic water splitting and H2 evolution using abundant compounds as electron donors are expected to contribute to construction of a clean and simple system for solar hydrogen production, and a solution of global energy and environmental issues in the future (361 references)

Semiconductor-based Photocatalytic Hydrogen Generation

Abstract: 2.3. Evaluation of Photocatalytic Water Splitting 6507 2.3.1. Photocatalytic Activity 6507 2.3.2. Photocatalytic Stability 6507 3. UV-Active Photocatalysts for Water Splitting 6507 3.1. d0 Metal Oxide Photocatalyts 6507 3.1.1. Ti-, Zr-Based Oxides 6507 3.1.2. Nb-, Ta-Based Oxides 6514 3.1.3. W-, Mo-Based Oxides 6517 3.1.4. Other d0 Metal Oxides 6518 3.2. d10 Metal Oxide Photocatalyts 6518 3.3. f0 Metal Oxide Photocatalysts 6518 3.4. Nonoxide Photocatalysts 6518 4. Approaches to Modifying the Electronic Band Structure for Visible-Light Harvesting 6519

The absolute energy positions of conduction and valence bands of selected semiconducting minerals

Abstract: The absolute energy positions of conduction and valence band edges were compiled for about 50 each semiconducting metal oxide and metal sulfide minerals. The relationships between energy levels at mineral semiconductor-electrolyte interfaces and the activities of these minerals as a catalyst or photocatalyst in aqueous redox reactions are reviewed. The compilation of band edge energies is based on experimental flatband potential data and complementary empirical calculations from electronegativities of constituent elements. Whereas most metal oxide semiconductors have valence band edges 1 to 3 eV below the H2O oxidation potential (relative to absolute vacuum scale), energies for conduction band edges are close to, or lower than, the H2O reduction potential. These oxide minerals are strong photo-oxidation catalysts in aqueous solutions, but are limited in their reducing power. Non-transition metal sulfides generally have higher conduction and valence band edge energies than metal oxides; therefore, valence band holes in non-transition metal sulfides are less oxidizing, but conduction band electrons are exceedingly reducing. Most transition-metal sulfides, however, are characterized by small band gaps (<1 eV) and band edges situated within or close to the H2O stability potentials. Hence, both the oxidizing power of the valence band holes and the reducing power of the conduction band electrons are lower than those of non-transition metal sulfides.

Nanoporous BiVO4 Photoanodes with Dual-Layer Oxygen Evolution Catalysts for Solar Water Splitting

Abstract: Bismuth vanadate (BiVO4) has a band structure that is well-suited for potential use as a photoanode in solar water splitting, but it suffers from poor electron-hole separation. Here, we demonstrate that a nanoporous morphology (specific surface area of 31.8 square meters per gram) effectively suppresses bulk carrier recombination without additional doping, manifesting an electron-hole separation yield of 0.90 at 1.23 volts (V) versus the reversible hydrogen electrode (RHE). We enhanced the propensity for surface-reaching holes to instigate water-splitting chemistry by serially applying two different oxygen evolution catalyst (OEC) layers, FeOOH and NiOOH, which reduces interface recombination at the BiVO4/OEC junction while creating a more favorable Helmholtz layer potential drop at the OEC/electrolyte junction. The resulting BiVO4/FeOOH/NiOOH photoanode achieves a photocurrent density of 2.73 milliamps per square centimenter at a potential as low as 0.6 V versus RHE.

Inorganic Materials as Catalysts for Photochemical Splitting of Water

Abstract: Photochemical splitting of water into H2 and O2 using solar energy is a process of great economic and environmental interest. Since the discovery of the first water splitting system based on TiO2 and Pt in 1972 by Fujishima and Honda, over 130 inorganic materials have been discovered as catalysts for this reaction. This review discusses the known inorganic catalysts with a focus on structure–activity relationships.