Microscopic and Optical Investigation of Morphology Controlled PbS Micro/Nano Crystals Synthesized Through Hydrothermal Route

摘要

Lead sulfide (PbS) microcrystals with various morphologies were synthesized successfully under varied reaction conditions by the assistance of surfactants sodium dodecyl sulfate and cetyl trimethylammonium bromide through a simple hydrothermal route. X-ray diffraction revealed the highly crystalline cubic rock-salt phase formation. Field emission scanning electron microscopic observations showed that PbS crystals with various morphologies including flake-like, cubic, fishbone-like and bi-pyramid-like structures. Average thickness of flakes varied within 40-100 nm. Different cubic structures such as bigger and smaller cubes having dimension of about 250 nm and 80 nm were observed. Whereas fishbone like structures were composed of a main stem with length upto 3 (mu)m and parallel branches of secondary arms. Detail structure and preferential growth direction of most complex structure bi-pyramid-like PbS was investigated by high resolution transmission electron microscopy images. The influence of different sulfur sources on the morphologies of the products and the growth mechanisms were presented in detail. Optical characterization of the products was carried out by using UV-vis spectroscopy.