Multifunctional semiconductor nanoheterostructures via site-selective silica encapsulation

10.1002/smll.201202096Small9111908-1915SMAL

Asymmetric dumbbells from selective deposition of metals on seeded Semiconductor nanorods

10.1002/anie.200906783Angewandte Chemie - International Edition49162888-2892ACIE

Affecting an Ultra‐High Work Function of Silver

An ultra‐high increase in the WF of silver, from 4.26 to 7.42 eV, that is, an increase of up to circa 3.1 eV is reported. This is the highest WF increase on record for metals and is supported by recent computational studies which predict the potential ability to affect an increase of the WF of metals by more than 4 eV. We achieved the ultra‐high increase by a new approach: Rather than using the common method of 2D adsorption of polar molecules layers on the metal surface, WF modifying components, l‐cysteine and Zn(OH)_{2}, were incorporated within the metal, resulting in a 3D architecture. Detailed material characterization by a large array of analytical methods was carried out, the combination of which points to a WF enhancement mechanism which is based on directly affecting the charge transfer ability of the metal separately by cysteine and hydrolyzed zinc(II), and synergistically by the combination of the two through the known Zn‐cysteine finger redox trap effect

Engineering fluorescence in Au-tipped, CdSe-seeded CdS nanoheterostructures

10.1002/smll.201100976Small7202847-285

Phosphine-free, low-temperature synthesis of tetrapod-shaped CdS and its hybrid with Au nanoparticles

Tetrapod-shaped CdS colloidal nanocrystals are synthesized using a facile, phosphine-free synthesis approach at low temperature. The arm length and diameter of CdS tetrapods can be easily tuned by using different source of sulphureous precursors, i.e., sulfur powder, thioacetamide, and sodium diethyldithiocarbamate. Moreover, the growth of Au nanoparticles onto CdS to form metal–semiconductor hybrid nanocrystals is also demonstrated. The tetrapod-shaped CdS nanocrystals exhibit strong arm-diameter-dependent absorption and photoluminescence characteristics. Importantly, the as-obtained CdS tetrapods exhibit promising photocatalytic activity for the water-splitting reaction in photoelectrochemical cells