Self‐Accelerating H<sub>2</sub> Evolution Activity by In Situ Transformation on Noble‐Metal‐Free Photocatalyst of Covalent Organic Framework and Cu<sub>2</sub>O Composite
Yu‐Han Liu, Xiaoyu Chu, Yanxia Jiang, Wei Han, Ya Wang, Luhua Shao, Guiling Zhang, Fengming Zhang
Abstract
Abstract It is expected that the activity of photocatalysts can remain the same or decrease as little as possible in photocatalysis reaction. Herein, for the first time, a self‐accelerating H 2 production activity in a noble‐metal‐free Cu 2 O/TpPa‐2‐COF photocatalyst is reported. It shows a beginning H 2 production rate of 4.41 mmol h −1 g −1 under visible light illuminance, while the activity kept increasing to 27.27 mmol h −1 g −1 after 25 h reaction, which is 6.2 times higher than the beginning activity and reaches a record high. It is confirmed that part of Cu 2 O in Cu 2 O/TpPa‐2‐COF in situ transformed to Cu 0 in photocatalytic reaction, which acting as cocatalyst promotes the separation of photogenerated charge carriers. Further density functional theory calculations demonstrate that the Schottky barrier height of Cu‐Cu 2 O (111) interface is much smaller than that of Pt‐Cu 2 O (111), supporting its more efficient effect than that with Pt as cocatalyst.