Building rapid charge transfer channel via engineering Ni coordinated flexible polymer for efficient solar hydrogen evolution

Building rapid charge transfer channel from photocatalysts to cocatalysts can greatly improve the photocatalytic performance, yet remains a grand challenge. In this work, a flexible polymer engineering strategy was utilized to fabricate a homogeneous conductive N-doped carbon (NC) layer between CdS photo-absorber and surface NiO cocatalyst. The detailed formation procedure of NC layers was unraveled by a series of in-situ and ex-situ temperature-dependent analysis. Such a bifunctional layer can serve as not only a rapid charge transfer channel for photo-induced charge carriers, but also modulate the adsorption of H on NiO cocatalyst for concertedly boosting solar hydrogen production performance (101.92 mmol h⁻¹ g⁻¹). The DFT calculation together with SI-XPS, PL, TRPL, EIS and photocurrent plots indicated that the generated built-in electric field with the direction from NiO nanoparticles to NC layers could accelerate the excited electrons transfer to active sites. Furthermore, the adsorption and desorption energy of hydrogen on NiO nanoparticles was also optimized by the NC layers, as verified by DFT calculation. This work provides new insights into interfacial engineering between catalysts and cocatalysts for highly efficient photocatalysis.