Title: Semiconductor-Ionic Nanocomposites for Next-Generation Energy Technologies

Speaker: Professor Bin Zhu, Department of Energy Technology, Royal Institute of Technology, Stockholm, Sweden

Date/Time: 24 April 2015 from 10:40-11:30 

Place: Sabancı University, FENS G035

Abstract: The semiconductor-ionic nanoncomposites are radical new functional materials. It makes use of interfaces and interactions in the interfacial regions between the constituent phases, which result in unique interfacial highways, for charge separation and transfer for solar cell; superionic conduction, oxidation and reduction redox reactions for catalysis, electrolysis and nano-FC (fuel cell) and electrolyte-free fuel cell (EFFC) (refs 1-5). The material architecture of the two-phase composite demonstrates a new scientific principle of function design and development based on the interfacial mechanism. This very differs from single-phase material by doping to create structural defects for bulk properties. The interfaces e.g. effective interfacial areas and percolative pathways play a significant important role. 

Advanced applications for these novel nanocomposite materials have been demonstrated. For example, conventional FCs are constructed with three distinct components: anode, cathode and electrolyte; while we used the semiconductor-ionic materials for successful EFFCs. Without using the electrolyte, it can be more efficient energy conversion technology. It was selected by Nature Nanotechnology as a research highlight (Fuel cell: Three in one. Nat. Nanotechnol. 6, 330 doi:10.1038/nnano.2011.89)  The properties of the junction and energy band alignment allow for direct ion transport and prevent internal electronic short circuiting, while, at the same time, major power losses due to distinct anode/electrolyte and electrolyte/cathode interfaces’ limits in FCs are removed. Very recently we applied the heterojunction principle of the cutting-edge perovskite solar cell into a new generation fuel-to-electricity device. It has demonstrated the new science and technology with strong energy and environmental impact with a broad view from fuel cell and solar cell as well as material science, nano-material and -technology, semiconductor physics and electrochemistry. Moreover, we have used the same device demonstrated solar cell functions. The same device can be used for both fuel and solar energy conversion is radical new technology not known from literature and others’ work.

All these successful and important applications are realized by unique functions created by the interfaces of the constituent phases in the unique semiconductor-ion nanocomposites that are fresh in the literature. Besides we have made many years continuous efforts on multifunctional nanocomposites through our EC-China NANOCOFC network, www.nanocofc.com.

References

1.       B. Zhu et al, Schottky junction effect on high performance fuel cells based on nanocomposite materials, Adv. Energy Mater. (2015) 1401895.

2.       B. Zhu B., L. Fan L. and P. Lund, Breakthrough fuel cell technology using ceria-based multi-functional nanocomposites. Appl. Energy 106 (2013), 163.

3.       B. Zhu, et al, A new energy conversion technology based on nano-redox and nano-device processes. Nano Energy, 2 (2013) 1179.

4.       B. Zhu, R. Raza, G. Abbas and M. Singh. An Electrolyte-Free Fuel Cell Constructed from One Homogenous Layer with Mixed Conductivity. Adv. Funct. Mater. 21 (2011) 2465.

5.       B. Zhu, R. Raza, H. Qin, Q. Liu and L. Fan. Fuel cells based on electrolyte and non-electrolyte separators. Energy Environ. Sci. 4 (2011) 2986.

Biography: Bin Zhu, PhD, Head of Fuel cell/Solar cell (FSC) group, KTH (Royal Institute of Technology) and Chair Professor, director for New Energy Conversion Lab. in Hubei University.

He received M.Sc., in 1987 from University of Sci. & Tech. of China and 1995 for Ph.D. from Chalmers University of Technology, Physics and Engineering Physics, Sweden and 10/ 95-12/97 for Postdoc. in Uppsala University (Ångström Lab.). Since 1998 moved to KTH and 1999 became associate professor in Dept of Chemical Engineering and Technology, and now in Dept of Energy Technology, KTH. He has been visiting professor for Aalto University and Nanyang Technological University as well as acted as guest professor and professor in several Chinese universities to co-supervise the research projects and Ph.D students.

Dr. Zhu has more than 200 publications in nano-composite ionic conductors and new functional semiconductor-ionic materials for advanced fuel cells: low temperature SOFCs, electrolyte-free fuel cells, single layer fuel cells and next generation fuel-to-electricity conversion, with the citation about 4000. He has been recently selected by Hubei Provincial 100-talent program to establish large research team/network for frontier research in fuel cells and solar cells. He is coordinating for EC - China FP6 NANOCOFC (Nanocomposites for advanced fuel cells) research network, www.nanocofc.com He is one of the Most Cited Researchers reported by Elsevier.

Zhu’s research has resulted in highly international impacts as leading role evaluated by Swedish national programs from e.g. "Evaluation of The Swedish Energy Agency Research Programme for Stationary Fuel Cells" and the Swedish Research Council international evaluation, with outstanding milestones achieved for: i) NANOCOFC Science and technology - a new field explored and established since last 10 years, with Zhu’s pioneer work followed by the world activities as a new fuel cell R&D; The nanoncomposites make use of interfaces and interactions in the interfacial regions between constituent phases, resulting in interfacial ionic conduction highways, i.e. superionic conduction, oxidation and reduction redox reactions for catalysis, electrolysis and fuel cell. It thus results in advanced low temperature, 300-600oC SOFCs and ii) A great breakthrough- electrolyte-free fuel cell (EFFC), “Three in One”. The fuel cell reactions are realized through the direct combination of protons and oxygen ions on the surface of the particles. “This streamlined design should help pave the way towards more cost efficient fuel cells and perhaps even the arrival of the hydrogen economy.” Based on EFFCs Zhu is leading the development of the new functional semiconductor-ionic materials and various junctions (p-n, Schottky, hybrid and bulk heterojunction) fuel cells without using the electrolyte layer and establishing the semiconductor-ionics (SEMIONICS) for next generation fuel-electricity and chemical and physical energy conversions.

Contact: Alpay Taralp