Molecule Dipole and Steric Hindrance Engineering to Modulate Electronic Structure of PTCDA/PTA for Highly Efficient Photocatalytic Hydrogen Evolution and Antibiotics Degradation

Abstract

AbstractInsufficient charge separation and slow exciton transport severely limit the utilization of perylene‐plane‐based organic photocatalysts. Herein, a novel PTCDA/PTA (perylene‐3,4,9,10‐tetracarboxylic dianhydride/perylenetetracarboxylic acid) is successfully prepared for the first time by the in situ crystallization of PTA on the surface of PTCDA through π–π interaction. The PTCDA/PTA loading with 8%PTCDA showed the optimum photocatalytic performance. The photocatalytic H2 evolution rate reached 45.06 mmol g−1 h−1, which is 1.93‐fold and 4506.00‐fold higher than that of pure PTA and PTCDA. Meanwhile, it also exhibited excellent antibiotics photodegradation activities, in which both the removal efficiency of tetracycline hydrochloride (TC‐HCl) and ofloxacin (OFL) are more over 90% within 30 min. By modulating the structures of perylene plane, the steric hindrance and internal dipole moments can be precisely tuned. These lead to the change of stacking mode, promoting the degree of π–π stacking and formation of strong internal electric field, while improved the photocatalytic activity. Excited state density functional theory (DFT) calculations unveil the redistribution of electron‐hole pairs, which obeys a type II mechanism. The proposed photocatalytic mechanism is determined by liquid chromatography‐mass spectrometry (LC‐MS). Besides, the toxicities of the degradation products are also evaluated. The work provides useful strategy for the design of high‐performance and multifunctional photocatalysts toward water remediation and energy production.