Molecular photoelectrochemical (PEC) devices are hampered by electron-hole recombination after photoinduced electron transfer (PET), causing losses in power conversion e ciency (PCE). Inspired by natural photosynthesis, we demonstrate the use of molecular machinery as a strategy to inhibit recombination, through organization of molecular components and unbinding of the nal electron acceptor after reduction. We show that preorganization of the macrocyclic 3-NDI-ring electron acceptor to the P STATION dye forming the P STATION :3-NDI-ring pseudorotaxane, enables a "ring launching" event, upon PET from P STATION to 3-NDI-ring releasing 3-NDI-ring •− . Implementing P STATION :3-NDI-ring into p-type dyesensitized solar cells (p-DSSCs) revealed a vefold increase in PCE compared to benchmark dye P1, unable to facilitate pseudorotaxane formation. This active repulsion of anionic 3-NDI-ring •− with concomitant reformation P STATION :3-NDI-ring circumvents recombination at semiconductor-dye interface, affording a twofold enhancement in hole lifetime. We envision this concept of supramolecular-directed charge-propagation will encourage further integration of molecular machinery into PEC devices.

This work reports ad ye-sensitized photoelectrochemical cell (DSPEC) that couples redox-mediated lightdriven oxidative organic transformations to reductive hydrogen (H 2)f ormation.T he DSPEC photoanodec onsists of am esoporousa nataseT iO 2 film on FTO (fluorine-doped tin oxide), sensitized with the thienopyrroledione-based dye AP11,w hileH 2 was formeda taFTO-Pt cathode. Irradiation of the dye-sensitizedp hotoanode transforms 2,2,6,6-tetramethylpiperidine 1-oxyl (TEMPO) to the oxidized TEMPO (TEMPO +), whicha cts as ac hemical oxidant for the conversion of benzyla lcohol. The TEMPO 0/ + couple,p reviously used as redoxm ediator in DSSC, mediates efficient electron transfer from the organic substrate to the photo-oxidized dye. AD SPEC photoreactorw as designed that allows in situ monitoring the reaction progress by infrared spectroscopy and gas chromatography.S ustained light-driven oxidation of benzyla lcoholt ob enzaldehydew ithin the DSPEC photoreactor,u sing of TEMPO as mediator,d emonstrated the efficiency of the device, with ap hotocurrent of 0.4 mA cm À2 ,a pproachingq uantitative Faradaic efficiency and exhibiting excellent device stability. Solar energy is an attractive CO 2-neutral energy source, providing % 4200 times the energy consumption estimated for 2035. [1, 2] Beyondw idely deployed silicon-based photovoltaic (PV) technology,d ye-sensitizeds olar cells (DSSCs) [3] present a low-cost alternative with improved performance in low/diffuse light conditions. DSSCs use molecular dyes, wide-bandg ap semiconductors and redox mediators to absorb light and separate charges affording efficienciest hat have surpassed 14 %. [4, 5] While the application of solar-to-electric energy conversion is increasing, long-term energy storageremains ac hallenge. Elec

The development of new redox couples provides a clear strategy to improve power conversion efficiency (PCE) in p-type dye-sensitized solar cells (p-DSSCs) through enabling improvements in open-circuit voltage (VOC).

Dye‐sensitized photoelectrochemical cells are promising devices in solar energy conversion. However, several limitations still have to be addressed, such as the major loss pathway through charge recombination at the dye‐semiconductor interface. Charge separating dyes constructed as push‐pull systems can increase the spatial separation of electron and hole, decreasing the recombination rate. Here, a family of dyes, consisting of polyphenylamine donors, fluorene bridges, and perylene monoimide acceptors, was investigated in silico using a combination of semi‐empirical nuclear dynamics and a quantum propagation of photoexcited electron and hole. To optimize the charge separation, several molecular design strategies were investigated, including modifying the donor molecule, increasing the π‐bridge length, and decoupling the molecular components through steric effects. The combination of a triphenylamine donor, using an extended 2‐fluorene π‐bridge, and decoupling the different components by steric hindrance from side groups resulted in a dye with significantly improved charge separation properties in comparison to the original supramolecular complex.

Molecular photoelectrochemical (PEC) devices are hampered by electron–hole recombination after photoinduced electron transfer (PET), causing losses in power conversion efficiency (PCE). Inspired by natural photosynthesis, we demonstrate the use of molecular machinery as a strategy to inhibit recombination, through organization of molecular components and unbinding of the final electron acceptor after reduction. We show that preorganization of the macrocyclic 3-NDI-ring electron acceptor to the PSTATION dye forming the PSTATION:3-NDI-ring pseudorotaxane, enables a “ring launching” event, upon PET from PSTATION to 3-NDI-ring releasing 3-NDI-ring•−. Implementing PSTATION:3-NDI-ring into p-type dye-sensitized solar cells (p-DSSCs) revealed a fivefold increase in PCE compared to benchmark dye P1, unable to facilitate pseudorotaxane formation. This active repulsion of anionic 3-NDI-ring•− with concomitant reformation PSTATION:3-NDI-ring circumvents recombination at semiconductor–dye interface, affording a twofold enhancement in hole lifetime. We envision this concept of supramolecular-directed charge-propagation will encourage further integration of molecular machinery into PEC devices.