A Mechanoresponsive Phase‐Changing Electrolyte Enables Fabrication of High‐Output Solid‐State Photobioelectrochemical Devices from Pigment‐Protein Multilayers

Abstract

Exploitation of natural photovoltaic reaction center pigment proteins in biohybrid architectures for solar energy harvesting is attractive due to their global abundance, environmental compatibility, and near-unity quantum efficiencies. However, it is challenging to achieve high photocurrents in a device setup due to limitations imposed by low light absorbance by protein monolayers and/or slow long-range diffusion of liquid-phase charge carriers. In an attempt to enhance the photocurrent density achievable by pigment proteins, here, an alternative solid-state device architecture enabled by a mechanoresponsive gel electrolyte that can be applied under nondenaturing conditions is demonstrated. The phase-changing electrolyte gel provides a pervading biocompatible interface for charge conduction through highly absorbing protein multilayers that are fabricated in a simple fashion. Assembled devices exhibit enhanced current stability and a maximal photoresponse of ≈860 µA cm , a fivefold improvement over the best previous comparable devices under standard illumination conditions. Photocurrent generation is enhanced by directional energy transfer through extended layers of light-harvesting complexes, mimicking the modular antenna/transducer architecture of natural photosystems, and by metastable radical pair formation when photovoltaic reaction centers are embedded throughout light-harvesting regions of the device.

Polychromatic solar energy conversion in pigment-protein chimeras that unite the two kingdoms of (bacterio)chlorophyll-based photosynthesis

“…1a). This can be evidenced in devices through the recording of action spectra of external quantum efficiency (EQE-the number of charges transferred per incident photon), which exhibit peaks and troughs that correspond to the absorbance spectra of the particular light-harvesting pigments that are coupled to charge separation in the device 12,[17][18][19][20][21] .…”

Biodegradable Protein-Based Photoelectrochemical Cells with Biopolymer Composite Electrodes That Enable Recovery of Valuable Metals

“…Solar energy conversion was achieved using the RC-LH1 pigment-protein complex from the photosynthetic bacterium Rhodobacter (Rba.) sphaeroides as the photovoltaic component [10][11][12][13][14] and a water-soluble analogue of natural ubiquinone-10 (Coenzyme-Q10) as a charge carrier (Fig. 1b).…”

A Barbeque-Analog Route to Carbonize Moldy Bread for Efficient Steam Generation

“…Solar energy is expected to have a profound impact on human future development as well as be the key to tackle the serious environmental and energy challenges the world faces today ( Creutzig et al., 2017 ). Besides the strong urge to develop more eco-friendly and cost-effective energy harvesting technologies ( Cheng et al., 2018 , Ravi et al., 2017 , Ravi et al., 2018 , Fan, 2017 , Carlé et al., 2017 , Singh et al., 2017 ), the pursuit of utilizing this abundant energy source in addressing some of the environmental and social issues like water crisis has also gained immense research interest in recent times ( Pile, 2017 , Gençer et al., 2017 ). Enormous efforts are made in desalination of seawater to mitigate the ill effects of water deficit emerging in various parts of the globe.…”