Engineering TiO2@polyaromatic carbon heterojunctions via biomass-derived precursors for efficient visible light photocatalytic H2 evolution

Photocatalytic hydrogen evolution represents a pivotal pathway for clean energy conversion. However, the development of high-performance photocatalysts is often constrained by unsustainable synthesis methods and, more fundamentally, by the limited ability to precisely control the interfacial structure for directed charge transport. Herein, we develop a green synthesis strategy to fabricate a polyaromatic carbon layer-encapsulated TiO 2 heterojunction bridged by interfacial Ti-O-C bonds. This is achieved through the controlled calcination of biomass-derived xylose, yielding carbonaceous layers with well-defined sp 2 -hybridized configurations. The optimized Pt-2X-T300 photocatalyst demonstrates a remarkable hydrogen evolution rate of 8570.9 μmol g −1  h −1 under visible light, which is approximately 1993 times higher than that of the Pt-T300 benchmark. The enhanced performance is attributed to efficient charge carrier separation driven by the interfacial Ti-O-C bond, which optimizes the band alignment between TiO 2 and sp 2 -carbon layers. Mechanistic studies verify that the atomic-level interface establishes a rapid electron transfer pathway, yielding an apparent quantum yield of ∼8.4 % at 420 nm. This work not only establishes a methodology for converting carbohydrates into tailored carbon nanostructures but also develops a novel Ti-O-C bridged TiO 2 @carbon heterojunction architecture, offering a novel approach for designing high-efficiency solar-driven hydrogen production systems.