Scholar: Eric Soto-Harrison
Major: Chemical Engineering / Material Science Emphasis & Applied Mathematics
Faculty Mentors: Dr. Victor Vazquez & Dr. Ravi Subramaniam
Research Topic: A study of the synthesis and photoactivity of tantalum oxides and their nitrogen derivatives: Improving performance of visible-spectrum solar fuel photocataylists with novel carbon modification techniques
Abstract: The practicality of a hydrogen-based energy economy has generated significant interest in a commercially viable process to split water. Research has recently focused on several materials which are capable of this using a wide range of solar spectrum radiation to generate hydrogen, and the challenges are now increasing stability and performance. This project aims to study the viability of increasing catalytic performance of tantalum oxide based photo-catalysts by creating a hetero-junction catalyst through the wrapping of nanoparticles with a reduced graphene oxide (RGO) layer. From these structures, numerous new and unstudied multi-junction structures are to be produced. It is thought RGO may be able to increase charge pair recombination time, facilitating efficient charge transportation owing to its exceptional conductive properties. Experimental results support improvement of photo current response using wet chemical synthesis methods and high development of highly crystalline microstructure. This study will focus on the ability of RGO modified tantalum nanoparticles to photo-catalyze redox reaction in solar radiation compared to control samples in a variety of tantalum based oxides and oxynitrides. Continuing preliminary studies on pure tantalum-oxide nano-particles, this study extends general techniques to improve photocatalytic performance in many of the systems being studied in the field today. In congruence with simulation results, presented methods demonstrate experimentally that many materials previously studied in the literature can have their catalytic performance improved many fold through introduction of a charge carrier such as graphene. In addition, we also seek to utilize corrected DFT methods (DFT+u) to model the effect of carbon and nitrogen doping on the photocatalyst, with the goal of finding some theoretical justification for the experimental trends in the electronic properties of newly studied materials. Synthesis methods for these hetero-junction catalysts and the performance effects of the modification are reported, and experimental methods to further improve performance are discussed.
New Scholar: 2017 cohort