Integrative Graduate
Education and
Research Traineeship

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Effect of Network Geometry on Electron Movment in a Titania Photoanode

Electron microscope and electrochemical characterization of inverse opal titania electrode

Projects:

Multiscale Phenomena in Soft Materials

Institution:

City University of New York City College

Primary Strategic Goal:

Discovery: Foster research that will advance the frontiers of knowledge, emphasizing areas of greatest opportunity and potential benefit and establishing the Nation as a global leader in fundamental transformational science and engineering.

Secondary Strategic Goal:

Learning: Build the Nation's research capability through critical investments in advanced instrumentation, facilities, cyber infrastructure, and experimental tools.

Achievement/Results

Background: Choosing the best colloidal assembly method (dip coating, sedimentation, or electrophoresis) the self-assembly of colloidal particles of various sizes into ordered, opal structures is facilitated (Figure A). Infiltration of the opal structures with a titania pre-cursor and sintering at 450ºC yields inverse opal structures where the position of void and solid areas is inverted (Figure B).

Results: 10 um thick films of titania inverse opal structures on conductive glass substrates have been produced. Electrodes with pore sizes ranging from 0.5 – 5 um have been produced (Figure C & D). Inverse opals titania electrodes display electrode-like behavior. The effect of pore size and film thickness on charge density is revealed (Figure E).

Address Goals

Impact: Goal 1: The utilization of an ordered electrode structure leads to an improved overall efficiency of the dye-sensitized solar cell. In addition, the pore size control allows flexibility in the dye choice. The study provides a way to understand the effect on network geometry on electron movement in the electrodes. As a result, the efficiency of dye-sensitized solar cells might be increased from the currently reported ~10 % leading to a better applicability of dye-synthesized solar cells in alternative energy capture securing the Nations position in this area.

Goal 2: The student carrying out this study is female. As such, her research activity presence a role model to other female students both at the undergraduate and masters’ level. As such the activities help to generate a world-class, broadly inclusive science and engineering workforce and expand the scientific literacy of all citizens.