Degradation of Cd-yellow paints: Ab initio study of native defects in {10.0} surface CdS
| Autor: | Laura Giacopetti, Alessandra Satta |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2016 |
| Předmět: |
Cadmium
010401 analytical chemistry Cadmium sulfate Ab initio chemistry.chemical_element 02 engineering and technology Electronic structure 021001 nanoscience & nanotechnology Photochemistry 01 natural sciences Acceptor DFT Cadmium sulfide 0104 chemical sciences Analytical Chemistry chemistry.chemical_compound chemistry Computational chemistry Vacancy defect CdS surface Density functional theory 0210 nano-technology Points defects Spectroscopy |
| Zdroj: | Microchemical journal 126 (2016): 214–219. doi:10.1016/j.microc.2015.12.005 info:cnr-pdr/source/autori:Giacopetti, Laura; Satta, Alessandra/titolo:Degradation of Cd-yellow paints: Ab initio study of native defects in {10.0} surface CdS/doi:10.1016%2Fj.microc.2015.12.005/rivista:Microchemical journal (Print)/anno:2016/pagina_da:214/pagina_a:219/intervallo_pagine:214–219/volume:126 |
| DOI: | 10.1016/j.microc.2015.12.005 |
| Popis: | Relevant effects produced at the surface of modern paintings include the growth of discolored crusts. In the specific case of cadmium yellow paints (CdS), white globular compounds mostly formed by hydrated cadmium sulfate and cadmium carbonate are observed. The origins of such chemical and physical alterations are still under debate. Structural defects in CdS, among other possible causes like photo-oxidation processes, may play a role in the degradation process. Their presence in the pigment surface alters the electronic structure of cadmium sulfide by forming acceptor levels in the gap of the semiconductor. Such levels make the surface more reactive in the interaction with external agents (oxygen, water...). To this end, we present a theoretical study of point defects, namely Cd- and S-vacancies, in the {10.0} CdS surface. The geometrical and electronic structures as well as the vacancy formation energies are determined with the use of a first method. All the calculations are performed within the framework of the density functional theory (DFT) in the Generalized Gradient Approximation (GGA-PBE) with the use of ultrasoft pseudopotentials. (C) 2015 Elsevier B.V. All rights reserved. |
| Databáze: | OpenAIRE |
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