J. Mater. Chem. A, 2022 DOI: 10.1039/D2TA00739H
Gengyu Tian, Rhodri Jervis, Joe Briscoe, Madga Titirici and Ana Jorge Sobrido*
Solar redox flow batteries constitute an emerging technology that provide a smart alternative for the capture and storage of discontinuous solar energy through the photo-generation of the discharged redox species employed in traditional redox flow batteries. Here, we show that a MoS2-decorated TiO2 (MoS2@TiO2) photoelectrode can successfully harvest light to be stored in a solar redox flow battery using vanadium ions as redox active species in both catholyte and anolyte, and without the use of any bias. MoS2@TiO2 photoelectrode achieved an average photocurrent density of ~0.4 mA cm-2 versus 0.08 mA cm-2 for bare TiO2, when tested for the oxidation of V4+ to V5+, attributed to a more efficient light harvesting and charge separation for the MoS2@TiO2 relative to TiO2. The designed solar redox flow cell exhibited an optimal overall solar-to-chemical conversion efficiency of ~4.78%, which outperforms previously reported solar redox flow batteries. This work demonstrates the potential of MoS2@TiO2 photoelectrode to efficiently convert solar energy in to chemical energy in a solar redox flow battery, and it also validates the great potential of this technology to increase reliability in renewable energies.