Search

Ionic liquids (ILs) possess effective functions in controlling the phase and morphology of nanomaterials. However, it is still unclear how ILs affect the morphology control and what the origin of adsorption selectivity of ILs is on different crystal facets. It is a challenge to develop a simple method to select the suitable kinds of ILs for achieving the controllable synthesis of nanomaterials with designable shape. Herein, density functional theory (DFT) calculations were combined with experiment to study the interaction mechanism between ILs and crystal facets. An important relationship is proposed, named as the geometric matching principle, in which the adsorption site of substrate should not only need to meet the space requirement for interionic stacking of ILs, but also needs to maximize the interaction between adsorbed ILs and substrate. This new finding is meaningful for prediction of the adsorption selectivity of ILs and clarification of their shape-controlled chemistry. [ABSTRACT FROM AUTHOR]

Uncovering the reason for structure-dependent thermoelectric performance still remains a big challenge. A low-temperature and easily scalable strategy for synthesizing Bi2Te3 nanostring hierarchical structures through solution-phase reactions, during which there is the conversion of 'homo-hetero-homo' in Bi2Te3 heteroepitaxial growth, is reported. Bi2Te3 nanostrings are obtained through the transformation from pure Bi2Te3 hexagonal nanosheets followed by TeBi2Te3 'nanotop' heterostructures to Bi2Te3 nanostrings. The growth of Bi2Te3 nanostrings appears to be a self-assembly process through a wavy competition process generated from Te and Bi3+. The conversion of homo-hetero-homo opens up new platforms to investigate the wet chemistry of Bi2Te3 nanomaterials. Furthermore, to study the effect of morphologies and hetero/homo structures, especially with the same origin and uniform conditions on their thermoelectric properties, the thermoelectric properties of Bi2Te3 nanostrings and TeBi2Te3 heterostructured pellets fabricated by spark plasma sintering have been investigated separately. [ABSTRACT FROM AUTHOR]