报告摘要：

The ever-growing need for energy generation and storage applications demands development of low-cost materials with high conversion efficiency and long-term stability. The applications include photovoltaic devices for energy generation and supercapacitors for energy storage. Colloidal suspensions of nanomaterials are attractive for use as inks for low-cost fabrication of thin film solar cells and energy storage photovoltaic devices by simple spin or spray coating processes. Among different classes of photovoltaic materials, copper-based semiconducting chalcogenides of the I-III-VI2 and I2-II-IV-VI4 family, such as CuInxGa1-xS2 and Cu2ZnSnS4, are of considerable interest for use in thin film solar cells. We have synthesized monodisperse CuInxGa1-xS2, Cu2ZnSnS4, CuSbS2 and other chalcogenide nanocrystals using facile solution-based methods. Depending on the chemical composition and synthesis conditions, the morphology, structure and band gap of the nanocrystals can be controlled. Layer-structured chalcogenide materials are also advantageous for supercapacitor applications owing to their ability to host a variety of atoms or ions, large ionic conductivity and high surface area. CuSbS2 is a layered ternary chalcogenide that is composed of earth-abundant and low toxicity elements. We have developed a simple colloidal method for the synthesis of CuSbSexS2-x mesocrystals over the whole composition range (0 ≤ x ≤ 2) by substitution of S with Se. Our approach yields mesocrystals with belt-like morphology for all the compositions. Structural studies indicate that substitution of sulfur with selenium in CuSbS2 enables tuning the width of the interlayer gap between the layers. To investigate the suitability of CuSbSexS2-x mesocrystals for supercapacitor applications, we have carried out electrochemical measurements by cyclic voltammetry and galvanostatic charge-discharge measurements in KOH, NaOH and LiOH electrolytes. Our investigations reveal that the mesocrystals exhibit promising specific capacitance values with excellent cyclic stability.

报告人：

Departments of Chemistry and Chemical & Biological Engineering
Center for Materials for Information Technology, University of Alabama, AL 35487, USA

Arunava Gupta is Distinguished University Research Professor and MINT Professor at the University of Alabama (UA). He holds a joint appointment in UA’s College of Arts and Sciences and College of Engineering, and is associate director of UA’s Center for Materials for Information Technology (MINT Center). Gupta received his undergraduate degree from the Indian Institute of Technology, Kanpur, and Ph.D. degree in Chemical Physics from Stanford University. Prior to joining UA’s faculty in 2004, he worked as a research staff member and manager at the IBM Thomas J. Watson Research Center in New York. Gupta’s expertise is in investigating thin films and nanostructured materials for use in information technology and energy applications. He has co-authored more than 400 peer-reviewed scientific articles and holds 30 US patents. Gupta is an elected fellow of the American Physical Society, the American Association for the Advancement of Science and the Materials Research Society. He received the Humboldt Research Prize in 2010, awarded by the Alexander von Humboldt Foundation. In 2014, he was awarded the CRSI Medal, given annually by the Chemical Research Society of India.