The Development of Biophotovoltaic Systems for Power Generation and Biological Analysis

Abstract

Biophotovoltaic systems (BPVs) resemble microbial fuel cells, but utilise oxygenic photosynthetic microorganisms associated with an anode to generate an extracellular electrical current, which is stimulated by illumination. Study and exploitation of BPVs have come a long way over the last few decades, having benefited from several generations of electrode development and improvements in wiring schemes. Power densities of up to 0.5 W m^-2 and the powering of small electrical devices such as a digital clock have been reported. Improvements in standardisation have meant that this biophotoelectrochemical phenomenon can be further exploited to address biological questions relating to the organisms. Here, we aim to provide both biologists and electrochemists with a review of the progress of BPV development with a focus on biological materials, electrode design and interfacial wiring considerations, and propose steps for driving the field forward.

Keywords: biophotoelectrochemistry; biophotovoltaics; electrode architecture; fuel cells; photosynthesis.

Figure 1

Schematic representation of a biophotovoltaic system (a), a power curve (b), results from chronoamperometry (c), and cyclic voltammetry measurements (d). The gold lines indicate values observed under illumination, and the grey lines indicate values observed in the dark. The cyclic voltammetry measurements correspond to a situation where illumination stimulates release of a redox species. See text for more details.

Figure 2

Schematic representation of the model cyanobacterium Synechocystis (a) and the eukaryotic microalga Chlamydomonas (b), showing the organisation of the photosynthetic thylakoid membranes and external membranes.

Figure 3

Schematic representation of two‐electrode (a) and three‐electrode (b) biophotovoltaic systems.

Figure 4

Schematic representation of different mechanisms of cell‐electrode wiring and electron transfer.