Dual Cocatalysts Synergistically Promote Perylene Diimide Polymer Charge Transfer for Enhanced Photocatalytic Water Oxidation
Wenlu Li, Zhen Wei, Yuqiang Sheng, Jingyi Xu, Yuehong Ren, Jianfang Jing, Jun Yang, Junshan Li, Yongfa Zhu
Abstract
Water oxidation is a critical reaction in artificial photosynthesis which is limited by a high reaction energy barrier and often requires matching cocatalysts. Dual cocatalysts Co 3 O 4 and Pt are combined with a perylene diimide (PDI) polymer, accomplishing a photocatalytic O 2 production rate of 24.4 mmol g –1 h –1 under visible light irradiation, which is a 5.4-fold enhancement compared with PDI alone. Moreover, the apparent quantum yield of the O 2 evolution reaction reaches 6.9% at 420 nm and remains 1.2% at 590 nm. The dual cocatalysts-constructed interfacial electric fields provide an anisotropic driving force for photogenerated holes to Co 3 O 4 and electrons to Pt, synergistically improving the spatial charge separation efficiency for water oxidation. Co 3 O 4 molecules serve as active sites for the water oxidation reaction to improve the utilization of photogenerated holes on the surface. This work provides a valuable demonstration of the interaction process and mechanism of cocatalysts, guiding the selection of cocatalysts for high-efficiency solar energy conversion.