Constructing an efficient electron coupling path is essential for enhancing photocatalytic hydrogen evolution. Here, guided by theoretical design and experimental validation, a Graphdiyne/CoBOx (GDY/CB) ohmic junction catalyst was developed, enabling highly efficient and directional transfer of photogenerated carriers. Density functional theory (DFT) calculations reveal that interfacial bonding between GDY and CoBOx induces strong electronic coupling, suppresses electron backflow, and promotes charge delocalization. Microstructural analyses (SEM/TEM) confirm that the 2D layered GDY framework intimately contacts CoBOx nanosheets, forming a “high-speed channel” for electron migration. In situ XPS under illumination directly captures the photoinduced electron transfer from CoBOx to GDY, evidencing the establishment of a unidirectional transfer pathway. Photoelectrochemical tests, together with the above characterizations, indicate that interfacial coupling markedly enhances hydrogen evolution by reducing transport resistance and optimizing surface kinetics. The optimized GDY/CB-30% exhibits a hydrogen evolution rate of 9.91 mmol·g−1·h−1, 7.56 times higher than pristine GDY and superior to most non-noble-metal photocatalysts. This work highlights carbon-based ohmic junctions as a strategy to overcome bandgap limitations through engineered electron transport.

Rational construction of graphdiyne-based ohmic junctions to promote visible-light hydrogen evolution through interfacial charge transfer dynamics
    Abstract
    1 Introduction
    2 Experimental procedures
        2.1 Procedure for graphdiyne (GDY) synthesis
        2.2 Synthesis of CoBOx (CB)
        2.3 Synthesis of GDY/CB
        2.4 Characterization and computational evaluation
    3 Experimental results and interpretations
        3.1 DFT calculation forecast
        3.2 Catalyst structural and morphological analysis
        3.3 HER performance evaluation
        3.4 Carrier transfer kinetics analysis
        3.5 Theoretical calculation analysis
        3.6 Photocatalytic hydrogen evolution mechanism analysis
    4 Conclusions
    References

• YuYu Wang(Analysis and Testing Center of Ningxia Hui Autonomous Region, North Minzu University, Yinchuan 750021, P. R. China)
• Mingxia Zheng(School of Chemistry and Chemical Engineering, Ningxia Key Laboratory of Solar Chemical Conversion Technology, Key Laboratory for Chemical Engineering and Technology, State Ethnic Affairs Commission, North Minzu University, Yinchuan 750021, P. R. China)
• Jing Xu(School of Chemistry and Chemical Engineering, Ningxia Key Laboratory of Solar Chemical Conversion Technology, Key Laboratory for Chemical Engineering and Technology, State Ethnic Affairs Commission, North Minzu University, Yinchuan 750021, P. R. China) Corresponding author
• Zhiliang Jin(School of Chemistry and Chemical Engineering, Ningxia Key Laboratory of Solar Chemical Conversion Technology, Key Laboratory for Chemical Engineering and Technology, State Ethnic Affairs Commission, North Minzu University, Yinchuan 750021, P. R. China)