ABSTRACT
Crystal facet engineering of semiconductors has been proven to be an effective strategy to increase photocatalytic performances. However, the mechanism involved in the photocatalysis is not yet known. Herein, we report our success in that photocatalytic performances of the Cl(-) ion capped CoO octahedrons with exposed {111} facets were activated by a treatment using AgNO3 and NH3·H2O solutions. The clean CoO {111} facets were found to be highly reactivity faces. On the basis of the polar structure of the exposed {111} surfaces, a charge separation model between polar {111} surfaces is proposed. There is an internal electric field between polar {111} surfaces due to the spontaneous polarization. The internal electric field provides a driving force for charge separation. The reduction and oxidation reactions selectively take place on the positive and negative polar {111} surfaces. The charge separation model provides a clear insight into charge transfer in the semiconductor nanocrystals with high photocatalytic activities and offer guidance to design more effective photocatalysts, solar cells, photoelectrodes, and other photoelectronic devices.
ABSTRACT
In the crystal structure of the title Schiff base, C(20)H(25)N(3)O(2), the salicylaldimine groups at each end of the mol-ecule are essentially planar and make a dihedral angle of 84.94â (3)° with each other. There are strong intra-molecular O-Hâ¯N hydrogen bonds and a weak inter-molecular N-Hâ¯O hydrogen bond.
ABSTRACT
In the title complex, [Co(C(15)H(14)NO)(2)], the Co(II) atom, situated on an inversion centre, is coordinated by two O and two N atoms from two symmetry-related bidentate Schiff base ligands in a slightly distorted square-planar geometry. The two phenolate rings form a dihedral angle of 10.53â (2)°.
