Stephanie L. Brock
Stephanie L. Brock
Research Interest/Area of Expertise
Synthesis, properties and applications of metal pnictide and chalcogenide extended solids and nanomaterials; sol-gel nanoparticle assembly; hybrid materials
Our research efforts are centered on the synthesis and characterization of novel inorganic solid state materials with unique and tunable properties, particularly low dimensional solids and nanomaterials. The research is highly interdisciplinary, with the aim to develop a fundamental understanding of how structure, particle size, and material physical properties are related in order to advance technologies such as information storage, sensing, energy conversion and catalysis. Projects presently underway include:
I. Transition Metal Pnictide Nanoparticles: Novel Materials for Magnetic and Catalytic Applications. Transition-metal pnictides (pnicogen = Group 15 element) exhibit a wide range of magnetic and electronic properties of fundamental and practical interest including superconductivity, ferromagnetism, and semiconductivity. However, the breath of composition space plus the high degree of covalency in these systems makes production of nanoparticles as single phase, low polydispersity samples a challenge. We have developed a range of strategies for the synthesis of transition metal pnictides as nanoparticles and nanostructures, enabling formation of binary and ternary phases such as MnAs, Ni2P and Mn2-xCoxP. We have been studying the size and dopant-dependent magnetic properties of MnAs to enable potential applications in magnetic refrigeration, whereas the work on Ni2P-based materials is allowing us to evaluate size, shape and composition effects on hydrodesulfurization activity (in collaboration with Prof. Mark Bussell, Western Washington University). Most recently, we have discovered that Mn-containing phosphide nanoparticles, such as MnCoP, are highly active electrocatalysts for water oxidation, opening up a new venue for study.
II. Sol-gel Strategies for Assembly of Metal Chalcogenide Nanoparticles into Functional Architectures. A major hurdle to the implementation of nanoparticles in solid state devices is a lack of methodologies that permit them to be assembled into functional architectures while retaining the unique, size-defined properties of the nanoparticle building block. We have shown that sol-gel strategies, long exploited for oxides, can also be used to assemble metal chalcogenide nanoparticles, including CdS, CdSe, PbS, and ZnS. The resultant gels resemble a cross-linked particulate polymeric network. This network can be dried supercritically to form low-density, highly porous aerogels. These materials combine the unique optical properties of the nanoparticle building blocks with the high surface area and electronically conducting framework of the aerogel. Currently, we are investigating the suitability of these materials for sensing, remediation and photovoltaic applications and exploiting this assembly methodology for phosphide nanoparticles.
Education – Degrees, Licenses, Certifications
- B.S., University of Washington, 1990
- Ph.D., University of California, Davis, 1995
- Postdoctoral Associate, University of Connecticut, 1995-1999
D. Li, H. Baydoun, C. N. Verani, S. L. Brock "Efficient Water Oxidation Using CoMnP Nanoparticles" Journal of the American Chemical Society, 2016, 138, 4006-4009.
A. Hitihami-Mudiyanselage, M. P. Arachchige, T. Seda, G. Lawes, S. L. Brock, "Synthesis and Characterization of Discrete FexNi2-xP Nanocrystals (0<x<2): Compositional Effects on Magnetic Properties" Chemistry of Materials, 2015, 27, 6592-6600.
Y. Zhang, R. Regmi, Y. Liu, G. Lawes, S. L. Brock "Phase-coexistence and Thermal Hysteresis in Samples Comprising Adventitiously Doped MnAs Nanocrystals: Programming of Aggregate Properties in Magnetostructural Nanomaterials" ACS Nano, 2014, 8, 6814-6821.
L. Korala, Z. Wang, Y. Liu, S. Maldonado, S. L. Brock "Uniform Thin Films of CdSe and CdSe(ZnS) Core(Shell) Quantum Dots by Sol-Gel Assembly: Enabling Photoelectrochemical Characterization and Electronic Applications" ACS Nano, 2013, 7, 1215-1223.
Q. Yao, S. L. Brock "Porous CdTe Nanocrystal Assemblies: Ligation Effects on the Gelation Process and the Properties of Resultant Aerogels" Inorganic Chemistry, 2011, 50, 9985-9992.
I. R. Pala, I. U. Arachchige, D. G. Georgiev, S. L. Brock "Reversible Gelation of II-VI Nanocrystals: The Nature of Interparticle Bonding and the Origin of Nanocrystal Photochemical Instability" Angewandte Chemie, 2010, 49, 3661-3665.
CHM 1230 General Chemistry 1 Laboratory, 1 credit hours W2016
CHM 5020 Intermediate Inorganic Chemistry II, 3 credit hours F2016