PEDOT-Carbon Nanotube Counter Electrodes and Bipyridine Cobalt (II/III) Mediators as Universally Compatible Components in Bio-Sensitized Solar Cells Using Photosystem I and Bacteriorhodopsin

Abstract

In nature, solar energy is captured by different types of light harvesting protein–pigment complexes. Two of these photoactivatable proteins are bacteriorhodopsin (bR), which utilizes a retinal moiety to function as a proton pump, and photosystem I (PSI), which uses a chlorophyll antenna to catalyze unidirectional electron transfer. Both PSI and bR are well characterized biochemically and have been integrated into solar photovoltaic (PV) devices built from sustainable materials. Both PSI and bR are some of the best performing photosensitizers in the bio-sensitized PV field, yet relatively little attention has been devoted to the development of more sustainable, biocompatible alternative counter electrodes and electrolytes for bio-sensitized solar cells. Careful selection of the electrolyte and counter electrode components is critical to designing bio-sensitized solar cells with more sustainable materials and improved device performance. This work explores the use of poly (3,4-ethylenedioxythiophene) (PEDOT) modified with multi-walled carbon nanotubes (PEDOT/CNT) as counter electrodes and aqueous-soluble bipyridine cobaltII/III complexes as direct redox mediators for both PSI and bR devices. We report a unique counter electrode and redox mediator system that can perform remarkably well for both bio-photosensitizers that have independently evolved over millions of years. The compatibility of disparate proteins with common mediators and counter electrodes may further the improvement of bio-sensitized PV design in a way that is more universally biocompatible for device outputs and longevity.

Evaluating the Effect of Iron(III) in the Preparation of a Conductive Porous Composite Using a Biomass Waste-Based Starch Template

“…Conductive porous materials possess a unique combination of properties and have become a global hot topic in the fields of catalysis, drug delivery, electronic devices, extracellular matrices, and tissue regeneration [11,[19][20][21][22][23][24][25]. Biopolymer-based conducting porous materials have been previously obtained through the chemical oxidation of 3,4-ethylenedioxythiophene (EDOT) using iron(III) ions [14,19,21,26].…”

Biomolecular and Biohybrid Systems for Solar Energy Conversion

“…Indeed, commonly used strategies to improve the interfacial electron transfer in biohybrid electroactive systems rely on the use of large amounts of toxic redox mediators, as well as expensive conductive substrates based on noble and rare elements. To address these design limitations, the groups of B. D. Bruce and C. Villarreal have collaborated to develop a new class of optimized biohybrid dye-sensitized solar cells (BSSCs) [2]. By using the innovative universal counterelectrode based on poly (3,4-ethylenedioxythiophene) (PEDOT) modified with multi-walled carbon nanotubes (PEDOT/CNT), and aqueous bipyridine cobalt II/III complexes as direct redox mediators, they improved the power conversion efficiency in two types of BSSCs with two different bio-photosensitizers, PSI and bacteriorhodopsin.…”