Research Interests

            Our research interests are focused on preparing porous materials of importance in adsorption, separation, catalysis, opto-electronics,and energy science by using new synthetic methods and strategies under the guidance of modern computational chemistry. The ultimate goal is to prepare new materials with desired structure and properties by using the so-called 'molecular engineering' approach. The on-going research projects include:

1. Design and synthesis of novel zeolites with specific pore structure
           Inorganic porous materials with various topological frameworks have been extensively studied due to their rich structural chemistry and widespread applications in areas as diverse as laundry detergents, oil refining and petrochemical industries, adsorbents, gas separations, agriculture and horticulture, pigments, and jewelry. Among these materials are the well-known porous aluminosilicates, i.e. the so-called zeolites, which were first discovered in nature in 1756 by Axel F. Cronstedt. A zeolite is a crystalline aluminosilicate with a three-dimensional framework structure that consists of TO4 (T = Si, Al) tetrahedra to form uniformly sized pore channels and/or cages of  molecular dimensions. Ever since the introduction of aluminosilicate molecular sieves (zeolites), zeolites and related molecular sieves have been one of the hottest topics amongst the areas of both scientific research and technological application.
            It is vital to synthesize porous materials with novel structure because the utility of these materials is intimately correlated to their geometrical features. Along with the deeper understanding of the relationships between the zeolite structure and its catalytic property in the industrial process, new demands have been put forward on zeolite structures, which include large-pore and multidimensional pore zeolites for improving catalytic efficiency, extra-large-pore crystalline molecule sieves for large molecule catalysis, chiral zeolites for chiral catalysis and separation, etc. We are making efforts to synthesize new zeolites with specific pore channels by using designed organic quaternary ammonium salts of certain size, geometry and hydrophobicity as structure-directing agents. The synthesis of these materials would provide insights into the crystallization of zeolites and further guide us to design and synthesize novel microporous crystals of specific pore structures.

Fig.1    Zeolite NUD-1 with 18-membered ring pores obtained in our group

2. Ordered porous semiconductors and ionic conductors
            As better and more diverse preparations of porous materials become available, these materials have been continuously improved their traditional applications in fields such as adsorption, separation, catalysis, etc. In addition, they have been found new use in applications such as semiconducting, ion-conducting, opto-electronic, sensing, and photonics. We have initiated a project to synthesize a new class of open-framework semiconductors with unique structures and specific functions by employing a new strategy, which involves self-assembly of inorganic polyhedral clusters such as Zintl ions (e.g. T4^4-, T9^4-, T = Si, Ge) as the structure building units in the presence of structure-directing agents. The obtaining materials, such as silicon or germanium, possess both porosity and semiconducting properties and may have potentials in applications in photonics, electronics, sensors and energy storage (e.g. Li ion battery). The synthetic chemistry acquired in this research may provide insights into the self-assembly of other inorganic clusters and nano particles, and guide future research in rational synthesis of functional materials with specific structures and properties.

Fig.2    Silicon hollow nanospheres

3. Multi-functional porous coordination polymers and crystalline organic open-frameworks
            Coordination polymers are a class of materials with a one-dimensional chain, a two-dimensional sheet or a three-dimensional framework structure that consists of metal ions or clusters and multidentate organic ligands of certain geometry via more or less covalent metal-ligand bonding. Because of the variety of metal ions with different electronic configurations and functional organic ligands, these materials have exhibited fascinating structural topologies and potential applications in adsorption, molecular sieving, and catalysis, resembling those of zeolites. In addition, they possess properties not traditionally associated with inorganic zeolites and molecular sieves, such as luminescence, conducting, photovoltaic, ferroelectric, magnetic and multi-functional optoelectronic properties. To date, thousands of coordination polymers have been synthesized and they are continuing to draw surprises with their fascinating structures and properties.
            Our interests in coordination polymers are to prepare compounds possessing both porosity and optoelectronic properties, with aims to obtain multi-functional materials that could be used as energy storage, molecular sensors, and molecular recognization. Our approach is to use principles and methods of molecular engineering, i.e., to combine judiciously chosen inorganic building units and multidentate ligands of certain coordination geometry and electronic configuration, leading to predesigned structural topologies.           

Fig.3    Microporous coordination polymer of metal sulfides

            In addition, we are interested in preparing crystalline organic frameworks and multi-dimensional supramolecular materials with charge transfer and host-guest properties, particularly those consisting of functional models of enzyme and chlorophyll for biomimetics.

                     Updated on 2014-06-15