Current research focuses photoelectrochemical (PEC) water splitting, also known as artificial photosynthesis, through which solar energy is captured and stored in the form of chemical fuel (H2). The goal is to find a photoelectrode material that utilizes solar radiation with high efficiency while enjoying decent chemical stability against the harsh PEC environment, through an integrated approach of material synthesis, photoelectrochemical studies, theoretical modeling, and advanced optical characterizations. A major research emphasis is the combinatorial synthesis of complex semiconductor metal oxide thin films/nanostructures for band gap engineering, using various techniques. The material screening is performed with photoelectrochemistry methods and coupled with ultrafast laser spectroscopy for a comprehensive understanding of the exciton dynamics and the interfacial charge transfer process. Other interests include the experimental/theoretical studies of nanophotonic/plasmonic nanostructures for improving light absorption in solar energy devices and applications in chemical/biochemical sensing.
Dissertation: Localized Surface Plasmon of Quasi-One-Dimensional Metallic Nanostructures
Projects: Photocatalytic water splitting on cross-linked TiO2 nanowire photoanode; On-chip electro-optical generation of single surface plasmon polariton
W. R. Zhang, D. H. Yan, K. Appavoo, J. J. Cen, Q. Y. Wu, A. Orlov, M. Y. Sfeir and M. Z. Liu*, Unravelling Photocarrier Dynamics beyond the Space Charge Region for Photoelectrochemical Water Splitting, Chem. Mater. 2017, DOI: 10.1021/acs.chemmater.7b00672.
D. H. Yan, J. J. Cen, W. R. Zhang, A. Orlov and M. Z. Liu*, Hydrothermal growth of ZnO nanowire arrays: fine tuning by precursor supersaturation, CrystEngComm 19, 584 (2017).
J. J. Cen, Q. Y. Wu, D. H. Yan, J. Tao, K. Kisslinger, M. Z. Liu*, and A. Orlov*, Photoelectrochemical water splitting with a SrTiO3:Nb/SrTiO3 n+–n homojunction structure, Phys. Chem. Chem. Phys. 19, 2760 (2017).
M. Z. Liu*, J. L. Lyons, D. H. Yan, and M. S. Hybertsen, Semiconductor-based photoelec-trochemical water splitting at the limit of very wide depletion region, Adv. Funct. Mater. 13, 219 (2016).
D. H. Yan, J. Tao, K. Kisslinger, J. J. Cen, Q. Y. Wu, A. Orlov, and M. Z. Liu*, The role of domain size and titanium dopant in nanocrystalline hematite thin films for water photolysis, Nanoscale 7, 18515-18523 (2015).
M. Z. Liu*, J. Tao, C.-Y. Nam, K. Kisslinger, L. H. Zhang, and D. Su, Surface-energy induced formation of single crystalline bismuth nanowires over vanadium thin film at room temperature, Nano Lett. 14, 5630–5635 (2014).
M. Z. Liu*, C.-Y. Nam, C. T. Black, J. Kamcev, and L. H. Zhang, Enhancing water splitting activity and chemical stability of zinc oxide nanowire photoanodes with ultrathin titania shells, J. Phys. Chem. C 117, 13396-13402 (2013).
F. Lu, Y. Tian, M. Z. Liu, D. Su, H. Zhang, A. Govorov, and O. Gang, Discrete nano-cubes as plasmonic reporters of molecular chirality, Nano Lett. 13, 3145-3151 (2013).
M. Z. Liu, N. d. L. Snapp, H. Park, Water photolysis with a cross-linked titanium dioxide nanowire anode, Chem. Sci. 2, 80 (2011).
M. Z. Liu, T.-W. Lee, S. K. Gray, P. Guyot-Sionnest, M. Pelton, Excitation of dark plasmons in metal nanoparticles by a localized emitter, Phys. Rev. Lett. 102, 107401 (2009).
M. Pelton, J. E. Sader, J. Burgin, M. Z. Liu, P. Guyot-Sionnest, and D. Gosztola, Damping of acoustic vibrations in gold nanoparticles, Nature Nanotech 4, 492 (2009).
M. Z. Liu, M. Pelton, and P. Guyot-Sionnest, Reduced damping of surface plasmons at low temperatures, Phys. Rev. B 79, 035418 (2009).
M. Z. Liu, P. Guyot-Sionnest, T.-W. Lee, and S. K. Gray, Optical properties of rodlike and bipyramidal gold nanoparticles from three-dimensional computations, Phys. Rev. B 76, 235428 (2007).
M. Pelton, M. Z. Liu, H. Y. Kim, G. Smith, P. Guyot-Sionnest, and N. F. Scherer, Optical trapping and alignment of single gold nanorods by using plasmon resonances, Opt. Lett. 13, 2075 (2006).
M. Z. Liu and P. Guyot-Sionnest, Mechanism of silver(I)-assisted growth of gold nanorods and bipyramids, J. Phys. Chem. B 109, 22192 (2005).