Research Overview

Our research interest centers on the development of synthetic methodologies to prepare novel materials for energy conversion and storage. These materials integrate uniform porosity, high surface area, semiconductivity, optical property, photocatalytic, acid- or base-catalytic properties and can have a variety of applications.

Design and Synthesis of Metal-Organic Framework Materials for Energy Related Applications

Metal-organic framework materials (MOFs) are among the most fascinating families of solid state materials, because of their highly tunable compositions, structures, and properties. In our group, various strategies for the synthesis of new porous MOFs are explored, with the focus on the use of different metallic elements and their various combinations. In addition, we also seek to functionalize MOFs with active sites for enhanced gas sorption properties. Other strategies used to tune the gas sorption properties include pore space engineering by using extra-framework ions or nested cage-in-cage configurations.

Semiconductors as Visible-Light Driven Photocatalyst

In order to achieve low-cost and efficient solar energy conversion, the discovery of efficient semiconductor materials and new conversion pathways is essential. Here our research focuses on the design and synthesis of efficient visible-light-driven photocatalytic materials based on crystalline metal oxides while developing a solid understanding of materials-design principles such as band engineering mechanism and composition-structure-property relationship. We focus on developing low-cost versatile synthetic methods to synthesize photocatalytic materials with highly responsive visible-light activity. Strategies for maximizing the visible-light activity include (1) compositional and structural control to achieve band gap engineering, (2) crystallinity and morphological control to enhance efficient charge separation, and (3) optical, photoelectrochemical and photocatalytic measurements to provide guidance for further tuning and optimizing synthetic parameters and structural features.

Synthesis and Organization of Semiconducting Clusters

Quantum confinement in size and dimension can lead to chemical, electrical, and optical properties that are substantially different from those observed for the bulk material. These new properties can lead to numerous technological applications. My research group is interested in exploring new synthetic methodologies to prepare nanoclusters with simultaneous control in size, surface features, and spatial arrangements from zero to three dimensions. We are particularly interested in crystalline nanoclusters with precisely defined compositions and sizes and in their superlattices with various connectivity. One of our recent successes in this area is the synthesis of the largest Cd-S cluster (by single crystal diffraction) containing as many as 54 metal sites.

Publications Highlighted in Journal Covers

A New Strategy for Making Lithium Metal-Organic Frameworks

Zheng, S.; Li, Y.; Wu, T.; Nieto, R., Feng, P.; Bu, X. Porous Lithium Imidazolate Frameworks Constructed with Charge-Complementary Ligands, Chem. Eur. J. 2010, 16, 13035-13040.

Metal Chalcogenide Supertetrahedral Clusters

Bu, X.; Zheng, N.; Feng, P. Tetrahedral chalcogenide clusters and open frameworks. Chemistry--A European Journal 2004, 10(14), 3356-3362.

Fast Ion Conductivity

Zheng, N.; Bu, X.; Feng, P. Synthetic design of crystalline inorganic chalcogenides exhibiting fast-ion conductivity. Nature 2003, 426, 428-432.