Photogalvanic cells based on lyotropic nanosystems: towards the use of liquid nanotechnology for personalised energy sources

Abstract

A lightweight, autonomous and practical, proof-of-concept electrical power source is developed within this work. It comprises a photoredox-active material embedded within the non-ionic surfactant subphase, with a second redox reagent present within the aqueous pseudophase of a lamellar (L_α) lyotropic liquid crystal framework, which is sandwiched between two electrodes, one of which acts in a sacrificial manner. This quasi-biphasic, entirely new-concept, electrochemical cell, based on electron transfer, rather than ion transfer, is shown to act as a photogalvanic device which, under violet light, is demonstrated to exhibit maximum light-to-electrical power conversion efficiency of ca. 2% (fill factor of 15%), with additional ability to act as an electrically-rechargeable electrochemical capacitor of voltage efficiency ∼85% and power efficiency ∼80%, and with estimated maximum energy density of ∼1 W h kg⁻¹ at a power density of ∼1 kW kg⁻¹.