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Biography:
Hiroshi Irie studied Inorganic Materials Science and received his B.E. and M.E. degrees from Tokyo Institute of Technology in 1992 and 1994, respectively. From 1994 to 1997, he worked at Sumitomo Metal Industries, LTD. as a research engineer. In 2000, he received his Ph. D. degree from the University of Tokyo in the Department of Interdisciplinary Studies. He was a research staff member at Kanagawa Academy of Science and Technology until 2001. He joined the University of Tokyo as a research associate in 2001 (Prof. Kazuhito Hashimoto’s lab.). He became a lecturer and an associate professor at the University of Tokyo in 2006 and 2008, respectively. He was promoted to a full professor in 2009 at Clean Energy Research Center in University of Yamanashi. His current research interests include creations of high-performance energy-conversion materials, such as photocatalysts, thermoelectric materials, and so on.
Abstract:
Various photocatalytic materials aiming at water splitting have been enthusiastically investigated because produced hydrogen (H2) is attractive as a clean and renewable fuel. To date, one of the candidate methods to split water to H2 and oxygen (O2) at a ratio of 2:1 under visible light is a combined system of half reaction photocatalysts, that is, H2-evolution and O2-evolution photocatalysts. However, because such the combination system, which is termed “Z-scheme”, requires a suitable redox couple, the system is not in fact able to split pure water. For the practical application, splitting pure water with no added chemicals is presumed to be favorable.
Recently, we reported an Ag-inserted solid-state hetero-junction photocatalyst for water-splitting under visible light, similar to a Z-scheme system but is not required for a redox mediator. So, this system is capable of splitting pure water. In this system, Ag acts as a solid electron mediator for water-splitting. We selected ZnRh2O4 (band-gap (Eg) = 1.2 eV) and AgSbO3 (Eg = 2.5 eV) as H2- and O2-evolution photocatalysts, respectively. The system was able to respond to visible light up to 545 nm depending on the photo-absorption capability of AgSbO3 (in fact, defective AgSbO3). So, we replaced AgSbO3 with Bi4V2O11 (Eg = 1.7 eV) as the O2-photocatalyst. Utilizing thus constructed Ag-inserted ZnRh2O4 and Bi4V2O11 photocatalyst, the simultaneous liberation of H2 and O2 from pure water at a stoichiometric ratio was achieved under irradiation with visible light up to wavelengths of 740 nm. In place of Ag, Au-inserted ZnRh2O4 and Bi4V2O11 photocatalyst was also able to accomplish overall pure-water splitting under visible light up to 740 nm with improved activity. Detailed investigations will be discussed at the conference.
Biography:
Prof. Dr. Jianhong XU received his B.Sc. and Ph.D. at Tsinghua University in 2002 and 2007 respectively. He continued his research in Tsinghua University as a postdoctor after graduation. He finished the postdoctoral program in May 2009, and became a formal faculty of the Department of Chemical Engineering, Tsinghua University. He had studied as a visiting scholar at Prof. David Weitz lab in Harvard University during 2012.7~2013.6. At present, his research areas are focusing on the microstructured chemical system, multiphase microfluidic technology and functional materials synthesis. He has more than 100 peer-reviewed publications. He got the “Excellent Young Scientists Fund” from the National Natural Science Foundation of China (NSFC) in 2013. In 2016, he was awarded as Young Scholar of “Chang Jiang Scholars Program of China” of MOE.
Abstract:
Droplet-based microfluidics has recently emerged as a new and promising area of science and technology in the last decades. Preparation of functional materials with microfluidics has attracted great interest from scientist and technologists with different backgrounds and occupations. This work will systematically introduce the recent progress in multiphase flow control in droplet-based microfluidics and preparation of smart emulsions and functional materials with microfluidics mainly by the author’s research group. Controlled multiphase flow with different flow patterns by multiphase microfluidics will be introduced. They have been utilized in novel materials preparation of considerable fields such as optics, biomedicine, controlled porous material and drug release.