Enhancing Carrier Transport via σ‐Linkage Length Modulation in D‐σ‐A Semiconductors for Photocatalytic Oxidation

Abstract

Carrier transport is an equally decisive factor as carrier separation for elevating photocatalytic efficiency. However, limited by indefinite structures and low crystallinities, studies on enhancing carrier transport of organic photocatalysts are still in their infancy. Here, we develop an σ‐linkage length modulation strategy to enhance carrier transport in imidazole‐alkyl‐perylene diimide (IMZ‐alkyl‐PDI, corresponding to D‐σ‐A) photocatalysts by controlling π–π stacking distance. Ethyl‐linkage can shorten π–π stacking distance (3.19 Å) the most among IMZ‐alkyl‐PDIs (where alkyl=none, ethyl, and n‐propyl) via minimizing steric hindrance between D and A moieties, which leads to the fastest carrier transport rates. Thereby, IMZ‐ethyl‐PDI exhibits remarkable enhancement in phenol degradation with 32‐fold higher rates than IMZ‐PDI, as well as the oxygen evolution rate (271‐fold increased). In microchannel reactors, IMZ‐ethyl‐PDI also presents 81.5 % phenol removal with high‐flux surface hydraulic loading (44.73 L m−2 h−1). Our findings provide a promising molecular design guideline for high‐performance photocatalysts and elucidate crucial internal carrier transport mechanisms.

Closing the loops on Southern Ocean dynamics: From the circumpolar current to ice shelves and from bottom mixing to surface waves

“…Despite the warming atmosphere, the annual maximum Antarctic sea ice extent had a positive, albeit weak, trend of 13,800 km 2 yr −1 from the beginning of satellite records in 1979 until the mid 2010s (J. Liu et al, 2023). A record maximum of 20.11 million km 2 was reached in September 2014 (NISDC, 2023).…”

“…Due to the extreme lows in Antarctic sea ice cover in recent years, there is currently no statistically significant net long-term trend in Antarctic sea-ice extent (Fogt et al, 2022;J. Liu et al, 2023).…”

Integrating Uranyl-Affinity “Hooks” into Conjugated Polymers Achieving Giant Built-in Electric Field for Boosting Photocatalytic Uranium Extraction from Seawater

“…An important breakthrough in overcoming the above challenges is to regulate the built-in electric field (IEF) by controlling the dipole moment of repeating units in conjugated polymers, in which the IEF has been certified to be the critical kinetic factor to determine PCS efficiency. − For example, Zhu and co-workers increased the asymmetry of the oligomer structure by introducing carboxyl groups into polymer side chains, which significantly increased the molecular dipole, thus enhancing the IEF and realizing desirable photocatalytic activity . Furthermore, donor–acceptor/donor−π–acceptor (D-A/D-σ-A/D-π-A) structures with larger π-electron delocalization to increase the dipole moment can also enhance the built-in electric field and facilitate charge separation and transport, thus remarkably promoting photocatalytic performances. − …”