The Journal of Physical Chemistry Letters最新文献

We investigate a continuous electrochemical pH-swing method to capture CO₂ from a gas phase. The electrochemical cell consists of a single cation-exchange membrane (CEM) and a recirculation of a mixture of salt and phenazine-based redox-active molecules. In the absorption compartment, this solution is saturated by CO₂ from a mixed gas phase at high pH. In the electrochemical cell, pH is reduced, and CO₂ is selectively released in a desorption step. We investigate the influence of redox molecule concentration on the charge storage capacity of the solution, as well as the impact of current density and solution recirculation rate on process performance. A theoretical framework, based on a minimal set of assumptions, is established. This framework describes the data very accurately and can be used for system design and optimization. We evaluate the trade-off between energy consumption and CO₂ capture rate and compare with published reports. We report a low energy consumption of 32 kJ/mol of CO₂ at a capture rate of 39 mmol/m²/min.

The organic semiconductor Y6 has been extensively used as an acceptor in organic photovoltaic devices, yielding high efficiencies. Its unique properties include a high refractive index, intrinsic exciton dissociation, and barrierless charge generation in bulk heterojunctions. However, the direct impact of the crystal packing morphology on the photophysics of Y6 has remained elusive, hindering further development of heterojunction and homojunction devices. Herein, we study the photogenerated species in multiple distinct Y6 crystal packing geometries via transient absorption spectroscopy and photovoltaic measurements of the corresponding single-component devices. Our results reveal that “co-facial” interactions drive the generation of charge-transfer states in neat films of Y6 and that exciton dissociation can be switched on and off by controlling these interactions. Additionally, we find that a combination of long-range order and more co-facial packing interactions accelerates the charge-transfer generation process and increases the exciton to charge-transfer conversion efficiency. These insights provide valuable structure–property relationships for optimizing device performance.

Exciton condensation, the Bose–Einstein-like condensation of quasibosonic particle-hole pairs, has been the subject of much theoretical and experimental interest and holds promise for ultraenergy-efficient technologies. Recent advances in bilayer systems, such as transition metal dichalcogenide heterostructures, have brought us closer to the experimental realization of exciton condensation without the need for high magnetic fields. In this perspective, we explore progress toward understanding and realizing exciton condensation, with a particular focus on the characteristic theoretical signature of exciton condensation: an eigenvalue greater than one in the particle-hole reduced density matrix, which signifies off-diagonal long-range order. This metric bridges the gap between theoretical predictions and experimental realizations by providing a unifying framework that connects exciton condensation to related phenomena, such as Bose–Einstein condensation and superconductivity. Furthermore, our molecular approach integrates exciton condensation with broader excitonic phenomena, including exciton-related entanglement and correlation, unlocking potential advancements in fields like quantum materials and energy transport. We discuss connections between recent experimental and theoretical work and highlight the discoveries that may arise from approaching exciton condensation from a molecular perspective.

We discuss the goals and the need for quantum information science (QIS) in chemistry. It is important to identify concretely how QIS matters to chemistry, and we articulate some of the most pressing and interesting research questions at the interface between chemistry and QIS, that is, “chemistry-centric” research questions relevant to QIS. We propose in what ways and in what new directions the field should innovate, in particular where a chemical perspective is essential. Examples of recent research in chemistry that inspire scrutiny from a QIS perspective are provided, and we conclude with a wish list of open research problems.