Functionalized Diatoms Poster Presentation

Bahls, L. (). Cyclotella gamma. In Diatoms of the United

States. Retrieved February 21, 2016, from

http://westerndiatoms.colorado.edu/taxa/species/cyclotella_

gamma.

Bahls, L. (). Synedra famelica. In Diatoms of the United

States. Retrieved February 21, 2016, from

http://westerndiatoms.colorado.edu/taxa/species/synedra_f

amelica.

Carr J, Hergenrader G and Troelstrup N (1986). A Simple,

Inexpensive Method for Cleaning Diatoms. Trans American

Microspocical Society 105(2): 152-157.

Jeffryes C, Campbell J, Li H, Jiao J, Rorrer G (2011). The

potential of diatom nanobiotechnology for applications in

solar cells, batteries, and electroluminescent devices.

Energy Environ Sci 4:3930-3941.

Spaulding S (2010). Didymosphenia geminata. In Diatoms of

the United States. Retrieved October 11, 2015, from

http://westerndiatoms.colorado.edu/taxa/species/didymosp

henia_geminata.

Modern day solar panels are inefficient.Although solar energy has garnered muchmedia attention, the solar panel actually has anefficiency of only about 11-15%. Scientists havebeen able to produce advanced solar panelsthat can reach about 25% efficiency, but,unfortunately, they are far too expensive toproduce commercially.

To increase solar cell efficiency, researchershave looked to the biology themed naturalprocess of photosynthesis as a guide (Jeffryes2011). This project aims to use principles fromboth plant thylakoids and nanomechanics toincrease efficiency. Mimicking the thylakoidinside plant chloroplast with titanium dioxidefunctionalized diatoms can potentially boostthe productivity of modern photovoltaicsystems.

Methods Conclusions

Functionalizing Diatoms with TiO2 for Solar Cell ApplicationsChris Dowdy, Sam Trappen, Dalton Reith, Dr. Chris Coughlin, Dr. Sesha Srinivasin & Dr. Melba Horton

Florida Polytechnic University, 4700 Research Way, Lakeland, FL 33805

Figure 4. SEM image of Cyclotella gamma. Scale bar

equals 10 μm (Bahls).

Literature Cited

Cleaning the Diatoms.Several species of diatoms were cleaned for this experiment,Cyclotella sp. (Figure 4), Synedra sp. (Figure 5) andDidymosphenia geminata (Figure 6). Samples of Cyclotella andSynedra were grown from purchased stock and Didymospheniawas obtained via the University of Colorado. The samples werecleaned via a bleaching process (Carr 1986) at variousconcentrations of sodium hypochlorite (4.125%, 2.75% and1.65%). Cleaned frustules from each concentration wereobserved under a compound microscope and scanning electronmicroscope (SEM) to determine which concentration cleanedthe diatoms with the least impact on the diatom structure.

Functionalizing the Diatoms.A solution to gel (sol-gel) chemical reaction method will beused to obtain titanium dioxide (TiO2) nanoparticles. Polymersof TiO2 will be seated onto the cleaned diatomic frustules. Thepurpose of the TiO2 is to interact with photons and harnesstheir energy creating an electric current across the frustuleacting as a substrate. The presence and quality of thesenanoparticles will be assessed by use of a SEM.

Introduction Results

Acknowledgements

Future Plans

Objective & Hypothesis

Improve the current state of the art for photovoltaic systems by adding titania

functionalized diatoms.

Development of Cleaning Process.Our cleaning process showed that a 1 to 4 concentration ofcommercial bleach to sample (1.65% bleach after mixing) waseffective at cleaning the organic material from diatom frustuleswhile avoiding destruction of the frustules by the base. Becauseof the lower concentration used, fewer rinses were needed thanthe previously published process (Carr 1986).

Florida Industrial and PhosphateResearch Institute (FIPR) Award.

This project was awarded First Place for the FIPR Award in theBiology Integrated Outlook Expo Poster Contest at FloridaPolytechnic University, Fall 2015.

Figure 6. SEM image of Didymosphenia geminata.

Scale bar equals 10 μm(Spaulding 2010).

A cheaper, safer and effective method for cleaningdiatoms was corroborated by this research. Thebleach method used at low concentrations is aseffective as the popular acid cleaning methods forfrustule cleaning. The resulting cleaned diatomsurfaces will act as a substrate for the placementof titania nanoparticles in the next step of thisexperiment.

TiO2 Attached to Diatoms.The diatoms will be functionalized for solar cell application bychemically affixing titania to the surface of the cleaned diatoms.These diatoms will be then be inserted into solar cells (perspecies) to determine which diatomic design is the mostefficient at energy production.

Sustainability Project.This project was funded by a grant from the Florida PolytechnicSustainability Committee for their annual ResearchCompetition. The winner will be announced on April 22, 2016(after the print date of this poster).

Caleb Riggs graciously helped design and 3D print a model for theproject.Florida Polytechnic University allowed access to labs andequipment for the project.

Certain designs of diatoms will provide greater energy efficiencies

inside solar cells.

Figure 3. Chris Dowdy viewing Didymosphenia geminata under a

microscope.

Figure 2. Dalton Reith cleaning diatoms for

functionalization.

Figure 1. Sam Trappencleaning diatoms for

functionalization.

"I'd put my money on the sun and solar energy. What a source of power! I hope we don't have to wait until oil and coal run out

before we tackle that."-Thomas A. Edison, 1931

Figure 5. SEM image of Synedra famelica. Scale bar

equals 10 μm (Bahls).