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2D covalent organic frameworks (COFs) could have well‐defined arrangements of photo‐ and electro‐active units that serve as electron or hole transport channels for solar energy harvesting and conversion, but their insufficient charge transfer and rapid charge recombination impede the sunlight‐driven photocatalytic performance. We report a new donor–acceptor (D–A) system, PyTz‐COF that was constructed from the electron‐rich pyrene (Py) and electron‐deficient thiazolo[5,4‐d]thiazole (Tz). With its bicontinuous heterojunction, PyTz‐COF demonstrated exceptional optoelectronic properties, photocatalytic ability in superoxide anion radical‐mediated coupling of (arylmethyl)amines and photoelectrochemical activity in sunlight‐driven hydrogen evolution. Remarkably, PyTz‐COF exhibited a photocurrent up to 100 μA cm−2 at 0.2 V vs. RHE and could reach a hydrogen evolution rate of 2072.4 μmol g−1 h−1. This work is paving the way for reticular design of highly efficient and highly active D–A systems for solar energy harvesting and conversion. [ABSTRACT FROM AUTHOR]

2D covalent organic frameworks (COFs) could have well‐defined arrangements of photo‐ and electro‐active units that serve as electron or hole transport channels for solar energy harvesting and conversion, but their insufficient charge transfer and rapid charge recombination impede the sunlight‐driven photocatalytic performance. We report a new donor–acceptor (D–A) system, PyTz‐COF that was constructed from the electron‐rich pyrene (Py) and electron‐deficient thiazolo[5,4‐d]thiazole (Tz). With its bicontinuous heterojunction, PyTz‐COF demonstrated exceptional optoelectronic properties, photocatalytic ability in superoxide anion radical‐mediated coupling of (arylmethyl)amines and photoelectrochemical activity in sunlight‐driven hydrogen evolution. Remarkably, PyTz‐COF exhibited a photocurrent up to 100 μA cm−2 at 0.2 V vs. RHE and could reach a hydrogen evolution rate of 2072.4 μmol g−1 h−1. This work is paving the way for reticular design of highly efficient and highly active D–A systems for solar energy harvesting and conversion. [ABSTRACT FROM AUTHOR]

Titelbild: Thiazolo[5,4-d]thiazole-Based Donor-Acceptor Covalent Organic Framework for Sunlight-Driven Hydrogen Evolution (Angew. Keywords: charge transfer; covalent organic frameworks; donor-acceptor; hydrogen production; solar energy harvesting EN charge transfer covalent organic frameworks donor-acceptor hydrogen production solar energy harvesting 1685 1685 1 01/20/21 20210125 NES 210125 B Donor-Akzeptor-Konjugation b und coplanare - -Stapelung befördern die Ladungstrennung und den Elektronentransport in einem porösen kovalent-organischen Gerüst, wie Hui Yang, Yue-Biao Zhang, Ke Wen et al. in ihrem Forschungsartikel auf S. 1897 beschreiben. Charge transfer, covalent organic frameworks, donor-acceptor, hydrogen production, solar energy harvesting. [Extracted from the article]

The development of highly efficient and low-cost approaches for catalytic hydrogen production from renewable energy is of tremendous importance for a truly sustainable hydrogen-based energy carrier in future life. Herein, the probability of utilizing solar light to product hydrogen from biomass derivative, glucose, was systematically demonstrated by using the periodically ordered TiO 2 nanotube arrays (TNTAs) assembled of Palladium quantum dots (Pd QDs), i.e. Pd QDs@ TNTAs as photoanode. The results showed that remarkably increased photocurrent density was obtained in the glucose solution compared to the pure KOH electrolyte over as-prepared photoelectrode, which indicated that the glucose could be faster oxidized than water oxidation, and thus could promote the hydrogen production on Pt cathode. The yield of hydrogen production from glucose oxidation reached as high as 164.8 μmol cm −1 over Pd QDs@TNTAs photoanode and Pt cathode system (denoted as Pd QDs@TNTAs/Pt) under the solar light irradiation for 6 h, which was about 15 times higher than that from pure water splitting. The superior hydrogen production performance could be attributed to the less endergonic process of the glucose oxidation than water, as well as the efficient synergistic photoelectrocatalytic (PEC) glucose oxidation over Pd QDs@TNTAs photoanode which possesses excellent photoelectrochemical performance and structure characteristics. Moreover, a probable mechanism for the PEC hydrogen production from biomass derivatives oxidation was proposed and discussed. [ABSTRACT FROM AUTHOR]