I-Corps: One-dimensional Titania-based Electrodes

Drexel University, Philadelphia PA

Investigators

Abstract

The broader impact/commercial potential of this I-Corps project is the development of cheap and green oxygen production. Nanostructured (NS) titanium dioxides, TiO2, have been, and remain, of significant commercial and research interest due to their use in a wide range of fields including paints, catalysis, photocatalysis, and others. Amongst these, NS TiO2, commercially sold as P25, commands a small, but important market share. P25 is manufactured by gas-flame synthesis, a relatively slow and expensive method. This method has, however, long been considered the gold standard in many catalytic and photocatalytic reactions but its use has been limited by its high cost. Should society elect to run on electrochemically generated, or green, hydrogen (H2), the rate limiting step is not at the H2 electrode, but rather the oxygen evolution reaction (OER) electrode. Commercially, iridium dioxide (IrO2) is used for OER. Iridium is one of the rarest elements on the Earth's crust. Apart from its cost, the world would rapidly run into serious supply issues if green H2 is mass produced. As a result, the proposed technology for producing H2 using NS TiO2 may be a cheaper and greener alternative to such OER catalysts. This I-Corps project is based on the development of affordable, stable, and high efficiency electrodes for electrolysis. The method is a one pot, near ambient, hugely scalable, bottom-up approach that converts cheap, green, abundant water, insoluble non-toxic precursors such as TiC and TiB2 into one-dimensional, Carbon-containing, titania-based nanofilaments (1DT NFs). Amongst the commercially available photocatalytic titanias, Evonik Aeroxide TiO2 P25, synthesized via flame pyrolysis of TiCl4, is widely used because of its high photocatalytic activity in many reaction systems. In many ways P25 has been considered the gold standard for catalysis and photocatalytic applications. Its major drawback, however, is its cost. Flame pyrolysis is expensive and does not yield large quantities of material. This project is a method of synthesis of materials that are not only significantly cheaper to fabricate but perform better than P25 in several applications including dye degradation and H2 production. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.