May 1, 2014
Growing pyrite crystals from molecular ink
Iron pyrite (FeS2 or Fool’s Gold) is an earth-abundant, non-toxic semiconductor that has seen enhanced research interest for use in energy conversion and storage. Pyrite is hailed as an energy-critical material due to its high absorption coefficient (>105 cm–1), a band gap of ~0.95 eV and high carrier mobility. Reporting in Nanotechnology, researchers at the University of Kansas (KU) in the United States have shown that they can directly convert colloidal iron sulfide molecular ink into pyrite crystals.
A multidisciplinary team, led by Shenqiang Ren, has succeeded in growing high-quality micron-sized pyrite crystals through a new hybrid method. The team found that a molecular ink of iron sulfide (FeS) nanowires can be employed to create films that can then be sulfurized.
Temperature and time dependence
Annealed films show vastly different phase and crystallinity dependent on temperature and time. These crystals allow for studies on the growth of pyrite crystals within the film by examining the temperature and time-dependent grain size. Temperature- and time-dependent growth models are obtained for this unique system.
Moreover, the team found that unique thermal measurements of pyrite crystal give an insight into the crystallinity and thermoconductivity; all of which will contribute to potential pyrite energy-critical applications, and promise to take its place as the "golden" material for future energy needs.
More information can be found in the journal Nanotechnology 25 205603.
About the author
This work was conducted in the Laboratory of Renewable and Emerging Nanomaterials at KU, led by Shenqiang Ren, Assistant Professor of Chemistry. With a background in materials chemistry and nanotechnology, his current research interests focus on the design, synthesis and assembly of emerging nanomaterials for green energy and multifunctional sensing applications. The lead author, Alec Kirkeminde, is a PhD candidate working on the pyrite material growth. All three others (Phil Gingrich, Huizhong Cui and Maogang Gong) are working on nanomaterial chemistry and energy conversion/storage applications. This work is supported by the US National Science Foundation.