Superhydrophobic Carbon Nanotube Electrode Produces a Near‐Symmetrical Alternating Current from Photosynthetic Protein‐Based Photoelectrochemical Cells

Abstract

The construction of protein‐based photoelectrochemical cells that produce a variety of alternating currents in response to discontinuous illumination is reported. The photovoltaic component is a protein complex from the purple photosynthetic bacterium Rhodobacter sphaeroides which catalyses photochemical charge separation with a high quantum yield. Photoelectrochemical cells formed from this protein, a mobile redox mediator and a counter electrode formed from cobalt disilicide, titanium nitride, platinum, or multi‐walled carbon nanotubes (MWCNT) generate a direct current during continuous illumination and an alternating current with different characteristics during discontinuous illumination. In particular, the use of superhydrophobic MWCNT as the back electrode results in a near symmetrical forward and reverse current upon light on and light off, respectively. The symmetry of the AC output of these cells is correlated with the wettability of the counter electrode. Potential applications of a hybrid biological/synthetic solar cell capable of generating an approximately symmetrical alternating current are discussed.

RETRACTED: Monolayers of pigment-protein complexes on a bare gold electrode: Orientation controlled deposition and comparison of electron transfer rate for two configurations

“…In recent years several attempts have been made to construct the functional devices based on biological entities extracted from photosynthetic systems (Kothe et al, 2014;Mershin et al, 2012;Mirvakili et al, 2014;Tan et al, 2012aTan et al, , 2012bTan et al, , 2013. Immobilized protein complexes on conducting surfaces retain their function of light absorption and energy transduction but the quantum efficiency of these devices is quite low.…”

Progress and perspectives in exploiting photosynthetic biomolecules for solar energy harnessing

“…25,26 This limitation thus gives rise to a new idea of making hybrid devices involving the biomolecular complexes effectively interfaced with manmade materials. 27 This research perspective has gathered much interest in the recent years and 20 there is a good progress in the number of research studies (Fig. 1) utilizing the photovoltaic abilities of natural photosynthetic systems for various device applications like solar cells, photodetectors, biosensors and solar fuel cells.…”

“…1) utilizing the photovoltaic abilities of natural photosynthetic systems for various device applications like solar cells, photodetectors, biosensors and solar fuel cells. 27 In this review, we shall discuss the recent developments and approaches in the in 25 vitro employment of photosynthetic biocomplexes with a focus on solar cell applications.…”

Directed assembly of defined oligomeric photosynthetic reaction centres through adaptation with programmable extra-membrane coiled-coil interfaces

“…1a, and see Fig. S1 in Supporting information) facilitates a highly-efficient photochemical charge separation that has been exploited for the construction of prototype solar cells [5], [6], [7], photoelectrochemical cells [8], [9], [10], [11], [12], [13], [14], [15], [16], [17], [18] and biosensors [19], [20]. Reaction centres from oxygenic phototrophs are of particular interest with regard to solar fuel synthesis through water splitting [21], [22] and the powering of catalysis by other redox proteins in non-native, hybrid systems [23], [24].…”

“…sphaeroides reaction centres incorporated into photoelectrochemical cells [5], [6], [7], [10], [18], [19]. Deposition of this protein on electrode surfaces in such systems is usually achieved by drop-casting or binding from solution, processes which give limited control over protein orientation at the electrode surface and even less control over packing of protein on the electrode surface.…”