Light-driven charge accumulation of a molecular Cu(I) complex for storage of photoredox equivalents. ChemRxiv. Preprint.The diurnal day/night cycle is presently of great interest for harvesting solar energy aimed at rendering suitable energy storage schemes. To this end we present a noble-metal free system based on a Cu(I) 4H-imidazolate complex, that is efficiently photoreduced in the presence of a sacrificial donor. The two-electron reduced species obtained can be stored in the dark for more than 14 hours. In a dark reaction, the photoredox equivalents can subsequently be transferred to the electron acceptors methyl viologen or oxygen, while the starting Cu(I) complex is almost completely regained. Repetition of this process revealed a charging capacity of 72% after four cycles. The implications of light-driven charge accumulation and prolonged storage times for solar battery and photoredox catalysis are discussed File list (2) download file view on ChemRxiv SupportInfo.pdf (2.15 MiB) download file view on ChemRxiv Manuscript.pdf (914.38 KiB) Supplementary InformationLight-driven charge accumulation of a molecular Cu(I) complex for storage of photoredox equivalents

The diurnal day/night cycle is presently of great interest for harvesting solar energy aimed at rendering suitable energy storage schemes. To this end we present a noble-metal free system based on a Cu(I) 4H-imidazolate complex, that is efficiently photoreduced in the presence of a sacrificial donor. The two-electron reduced species obtained can be stored in the dark for more than 14 hours. In a dark reaction, the photoredox equivalents can subsequently be transferred to the electron acceptors methyl viologen or oxygen, while the starting Cu(I) complex is almost completely regained. Repetition of this process revealed a charging capacity of 72% after four cycles. The implications of light-driven charge accumulation and prolonged storage times for solar battery and photoredox catalysis are discussed

The diurnal day/night cycle is presently of great interest for harvesting solar energy aimed at rendering suitable energy storage schemes. To this end we present a noble-metal free system based on a Cu(I) 4H-imidazolate complex, that is efficiently photoreduced in the presence of a sacrificial donor. The two-electron reduced species obtained can be stored in the dark for more than 14 hours. In a dark reaction, the photoredox equivalents can subsequently be transferred to the electron acceptors methyl viologen or oxygen, while the starting Cu(I) complex is almost completely regained. Repetition of this process revealed a charging capacity of 72% after four cycles. The implications of light-driven charge accumulation and prolonged storage times for solar battery and photoredox catalysis are discussed

The diurnal day/night cycle presently is a great challenge for the harvest of solar energy rendering suitable energy storage schemes inevitable. In the described experiments a Cu(I) 4H-imidazolate complex is efficiently photoreduced in the presence of a sacrificial donor. The obtained two-electron reduced species is stored for more than 14 hours in the dark. In a dark reaction, the stored photoredox equivalents can be transferred to an electron acceptor while the starting Cu(I) complex is almost completely regained. Repetition of the photoreduction/reoxidation revealed a photoreduction efficiency of 72% after four cycles.