Construction of Efficient Photocatalytic Hydrogen Evolution System using Red Blood Cell Ghosts as Scaffold

Abstract The development of efficient photocatalytic hydrogen (H ₂ ) evolution systems is attracting considerable interest owing to the usefulness of H ₂ as a renewable and clean energy source. Widely studied systems for light‐driven H ₂ evolution consist of multiple components, and assembling these components on a scaffold is essential to facilitate electron transfer between them, to enable high H ₂ yields. Here, red blood cell ghost (RBCG) is used as a scaffold to construct a three‐component system comprising [Ru(bpy) ₃ ] ²⁺ (photosensitizer), methyl viologen (MV ²⁺ , electron relay), ethylnediaminetetraacetic acid (EDTA, sacrificial electron donor), and platinum nanoparticles (Pt NPs, catalyst). Pt NP‐deposited RBCG ( Pt@RBCG ) and Pt NP‐ and Ru complex‐deposited RBCG ( Pt•Ru@RBCG ) are prepared. In particular, the Pt@RBCG system comprising Pt@RBCG , [Ru(bpy) ₃ ] ²⁺ , MV ²⁺ , and EDTA exhibits a higher H ₂ yield than the system without RBCG. The Pt NPs, which are highly dispersed on the RBCG cytoskeleton, contribute to the high catalytic activity of Pt@RBCG for H ₂ evolution. Furthermore, Stern–Volmer analysis and quantification of the methyl‐viologen radical cation (MV ^+• ) reveal that the RBCG environment does not affect the electron transfer process or MV ^+• formation in the Pt@RBCG system. This study demonstrates the versatility of RBCGs as a scaffold for controlling sophisticated reactions involving multiple components.