Dual Cocatalysts Synergistically Promote Perylene Diimide Polymer Charge Transfer for Enhanced Photocatalytic Water Oxidation

Water oxidation is a critical reactionin artificialphotosynthesiswhich is limited by a high reaction energy barrier and often requiresmatching cocatalysts. Dual cocatalysts Co3O4 and Pt are combined with a perylene diimide (PDI) polymer, accomplishinga 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 reactionreaches 6.9% at 420 nm and remains 1.2% at 590 nm. The dual cocatalysts-constructedinterfacial electric fields provide an anisotropic driving force forphotogenerated holes to Co3O4 and electronsto Pt, synergistically improving the spatial charge separation efficiencyfor water oxidation. Co3O4 molecules serve asactive sites for the water oxidation reaction to improve the utilizationof photogenerated holes on the surface. This work provides a valuabledemonstration of the interaction process and mechanism of cocatalysts,guiding the selection of cocatalysts for high-efficiency solar energyconversion.