Premium
Über die spektrale Sensibilisierung von Zinkoxid: I. Sorptionsverhalten von o,o ′‐Dihydroxyazofarbstoffen
Author(s) -
Brändli R.,
Rys P.,
Zollinger H.,
Oswald H. R.,
Schweizer F.
Publication year - 1970
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.19700530529
Subject(s) - chemistry , zinc , monolayer , adsorption , toluene , saturation (graph theory) , molecule , polymer chemistry , nuclear chemistry , organic chemistry , mathematics , combinatorics , biochemistry
o,o ′‐Dihydroxyazo compounds are spectral sensitizers for the photosemiconductor properties of zinc oxide. It is shown that 1‐(2‐hydroxyphenylazo‐)‐2‐naphthol (II) forms a 1:1 Zn complex on the surface of ZnO particles if adsorbed from toluene solution. With most samples of ZnO a Langmuir type adsorption isotherm is obtained. The concentration of the dye at saturation relative to the BET surface of the ZnO particles correponds to a slightly oblique edge‐on arrangement of the dye molecules on the surfaces. In the case of ZnO pretreated with propionic acid and having taken up dye in excess of a monolayer, it can be shown by electron microscopy that tail‐like complexes (zinc: dye ratio = 1:1) are formed, and that these complexes contain zinc which was originally on the particle surfaces.