Crystallized Poly(Triazine Imide) Decorated with Dynamically Coordinated PdII Complex for Efficient Photocatalytic Overall Water Splitting.

Abstract

Exploring photocatalysts capable of overall water splitting without the need of sacrificial agents or external bias holds significant practical importance. Herein, crystallized poly(triazine imide) (cPTI) loaded with CoO_x as oxygen evolution photocatalyst is decorated with (FFV)₂PdCl₂ complex (FFV = Fluoflavin) for constructing a novel Z-scheme heterojunction. The dynamic coordination between the Pd^II ion and FFV ligands in (FFV)₂PdCl₂ results in unsaturated Pd^II active sites as the excellent hydrogen evolution photocatalyst. The resultant (FFV)₂PdCl₂/cPTI-CoO_x heterojunction delivers excellent overall water splitting activity with H₂/O₂ yields up to 201/101 μmol h^-1 under the illumination of Xe-lamp and an apparent quantum yield of 19.8% at 365 nm. Mechanistic studies reveal that the Z-scheme charge transfer mechanism in (FFV)₂PdCl₂/cPTI-CoO_x effectively promotes the photoinduced charge separation, while maintaining high redox capacity for overall water splitting. This work presents the first instance of integrating crystallized poly(triazine imide) with dynamically coordinated complex, paving a new way for manufacturing highly efficient overall water splitting system.