scholarly journals Hydrogen evolution from water using CdS as photosensitizer

1999 ◽  
Vol 1 (2) ◽  
pp. 75-78
Author(s):  
Tatiana Oncescu ◽  
M. Contineanu ◽  
Lucia Meahcov
Keyword(s):  
Hydrogen Evolution ◽  
Irradiation Time ◽  
Pt Catalyst ◽  
Redox Catalyst ◽  
System Temperature ◽  
Copolymer 1 ◽  
Brus Equation ◽  
Colloidal Cds

Colloidal chemical approaches are increasingly utilised for the preparation and stabilization of semiconductor nanoparticles.We prepared a colloidal CdS in excess ofNa2Susing a method described in the literature and determined the particle size from its absorption spectrum by Brus equation. A diameter of about 50Å was calculated. For the stabilization of colloid we choosed from various tested polymers a 1% in weight copolymer (1/1), styrene/maleic anhydride. As redox catalyst we used colloidal Pt obtained “in situ” by irradiaton ofPtCl6K2. We established the role of each of the system partners as: CdS concentration,Na2Sexcess, Pt catalyst concentration, the irradiation time, and the system temperature. We studied the influence of each participant to the hydrogen evolution in order to optimize this system.The formation of nanosize composite particlesCd1−xZnxSshowed an increasing ofH2amount generated under irradiation, in comparison with CdS particles.The results obtained permitted us to calculate the turnover number (TO) of the system.

scholarly journals Multifunctional Polyoxometalate-Platforms for Supramolecular Light-driven Hydrogen Evolution

2021 ◽  
Author(s):  
Salam Maloul ◽  
Matthias van den Borg ◽  
Carolin Müller ◽  
Linda Zedler ◽  
Alexander Mengele ◽  
...  
Keyword(s):  
Energy Conversion ◽  
Hydrogen Evolution ◽  
Platinum Complex ◽  
Pt Catalyst ◽  
Central Research ◽  
Energy Conversion And Storage ◽  
Visible Light Driven ◽  
The Individual ◽  
Electrostatic Coupling

Multifunctional supramolecular systems are a central research topic in light-driven solar energy conversion. Here, we report a polyoxometalate (POM)-based supramolecular dyad, where two platinum-complex hydrogen evolution catalysts are covalently anchored to an Anderson polyoxomolybdate anion. Supramolecular electrostatic coupling of the system to an iridium photosensitizer enables visible light-driven hydrogen evolution. Combined theory and experiment demon-strate the multifunctionality of the POM, which acts as photosensitizer / catalyst-binding-site and facilitates light-induced charge-transfer and catalytic turnover. Chemical modification of the Pt-catalyst site leads to increased hydrogen evolution reactivity. Mechanistic studies shed light on the role of the individual components and provide a molecular understanding of the interactions which govern stability and reactivity. The system could serve as a blueprint for multifunctional polyoxometalates in energy conversion and storage.

{10-12} Twinning Mechanism During In Situ Micro-Tensile Loading of Pure Mg: Role of Basal Slip and Twin-Twin Boundary Interaction

2020 ◽  
Author(s):  
Nicolò Maria della Ventura ◽  
Szilvia Kalácska ◽  
Daniele Casari ◽  
Thomas Edward James Edwards ◽  
Johann Michler ◽  
...  
Keyword(s):  
Twin Boundary ◽  
Basal Slip ◽  
Tensile Loading ◽  
Boundary Interaction

The role of (bio)surfactant sorption in promoting the bioavailability of nutrients localized at the solid-water interface

1999 ◽  
Vol 39 (7) ◽  
pp. 91-98 ◽  
Author(s):  
Ryan N. Jordan ◽  
Eric P. Nichols ◽  
Alfred B. Cunningham
Keyword(s):  
Mass Transfer ◽  
Cell Membrane ◽  
Substrate Concentration ◽  
Water Interface ◽  
Industrial Systems ◽  
Solid Liquid Interface ◽  
Solid Liquid ◽  
Surfactant Sorption

Bioavailability is herein defined as the accessibility of a substrate by a microorganism. Further, bioavailability is governed by (1) the substrate concentration that the cell membrane “sees,” (i.e., the “directly bioavailable” pool) as well as (2) the rate of mass transfer from potentially bioavailable (e.g., nonaqueous) phases to the directly bioavailable (e.g., aqueous) phase. Mechanisms by which sorbed (bio)surfactants influence these two processes are discussed. We propose the hypothesis that the sorption of (bio)surfactants at the solid-liquid interface is partially responsible for the increased bioavailability of surface-bound nutrients, and offer this as a basis for suggesting the development of engineered in-situ bioremediation technologies that take advantage of low (bio)surfactant concentrations. In addition, other industrial systems where bioavailability phenomena should be considered are addressed.

THE ROLE OF BACTERIAL COMMUNITIES ON IN-SITU ARSENIC AND IRON CYCLING IN RIVERBANKS ALONG THE MEGHNA RIVER, BANGLADESH

2020 ◽  
Author(s):  
Kimberly D. Myers ◽  
◽  
Katrina Lee Jewell ◽  
P.S.K. Knappett ◽  
Mehtaz M. Lipsi ◽  
...  
Keyword(s):  
Bacterial Communities ◽  
Iron Cycling

scholarly journals A structurally versatile nickel phosphite acting as a robust bifunctional electrocatalyst for overall water splitting

2018 ◽  
Vol 11 (5) ◽  
pp. 1287-1298 ◽  
Author(s):  
Prashanth W. Menezes ◽  
Chakadola Panda ◽  
Stefan Loos ◽  
Florian Bunschei-Bruns ◽  
Carsten Walter ◽  
...  
Keyword(s):  
Hydrogen Evolution ◽  
Water Splitting ◽  
Oxygen Evolution ◽  
Bifunctional Electrocatalyst ◽  
Overall Water Splitting

The mechanistically distinct and synergistic role of phosphite anions in hydrogen evolution and nickel cations in oxygen evolution have been uncovered for active and durable overall water splitting catalysis in nickel phosphite.

Promoting Hydrogen Evolution of g-C3N4 Based Photocatalyst by Indium and Phosphorus Co-doping

2021 ◽  
Author(s):  
Xiao-Hang Yang ◽  
Chi Cao ◽  
Zilong Guo ◽  
Xiaoyu Zhang ◽  
Yaxin Wang ◽  
...  
Keyword(s):  
Hydrogen Evolution ◽  
Post Treatment ◽  
Experimental Results ◽  
Indium Chloride ◽  
Co Doping ◽  
In Situ Copolymerization ◽  
Co Doped

Indium and phosphorus co-doped g-C3N4 photocatalyst (In,P-g-C3N4) was prepared by K2HPO4 post-treatment of indium doped g-C3N4 photocatalyst (In-g-C3N4) derived from in-situ copolymerization of dicyandiamide and indium chloride. The experimental results...

How Artefacts Do Leadership: A Ventriloquial Analysis

2021 ◽  
pp. 089331892199807
Author(s):  
Jonathan Clifton ◽  
Fernando Fachin ◽  
François Cooren
Keyword(s):  
Organizational Communication ◽  
Recent Work ◽  
Distributed Leadership ◽  
Network Theory ◽  
Actor Network Theory ◽  
Fine Grained ◽  
Naturally Occurring ◽  
Human Actors

To date there has been little work that uses fine-grained interactional analyses of the in situ doing of leadership to make visible the role of non-human as well as human actants in this process. Using transcripts of naturally-occurring interaction as data, this study seeks to show how leadership is co-achieved by artefacts as an in-situ accomplishment. To do this we situate this study within recent work on distributed leadership and argue that it is not only distributed across human actors, but also across networks that include both human and non-human actors. Taking a discursive approach to leadership, we draw on Actor Network Theory and adopt a ventriloquial approach to sociomateriality as inspired by the Montreal School of organizational communication. Findings indicate that artefacts “do” leadership when a hybrid presence is made relevant to the interaction and when this presence provides authoritative grounds for influencing others to achieve the group’s goals.

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