大潛力，為高性能光催化劑和先進電化學設備鋪平了道路。;Junctions between two-dimensional (2D) materials form a new class of nanostructures that enable abrupt transitions in electronic structure, providing unique opportunities for advanced electrochemical applications. These sharp interfaces create localized electronic states and strong electric fields, enhancing their functional capabilities.
This thesis explores two primary areas: the application of lateral graphene p-n junctions for electrodeposition and the enhancement of photocatalytic activity in molybdenum disulfide (MoS2) homojunctions.
In the first part, lateral graphene p-n junctions are employed to achieve high spatial resolution and dynamic controllability in electrochemical processes. A bottom-up junction formation technique enables sub-nanometer precision in nanoparticle deposition, facilitating the creation of complex hierarchical materials such as aligned one-dimensional fractals. These fractals serve as novel substrates for surface-enhanced Raman spectroscopy (SERS). Additionally, dynamic tunability is demonstrated by depositing one-dimensional nanostructures that connect arbitrary points with adjustable strength and orientation, supporting axon-like growth of interconnected neurons for advanced neuromorphic circuits.
In the second part, MoS2 is investigated for catalysis and sustainable energy conversion, despite the inertness of its basal plane. This study introduces a technique to enhance the catalytic activity of continuous MoS2 films by preferentially activating buried grain boundaries (GBs) through mild UV irradiation, significantly boosting GB activity to match the catalytic performance of MoS2 edges. This enhancement is confirmed through site-selective photodeposition and micro-electrochemical hydrogen evolution reaction measurements. Spectroscopic analysis and ab-initio simulations reveal that substitutional oxygen functionalization at the GBs drives this catalytic enhancement, increasing activity by an order of magnitude.
This thesis demonstrates the transformative potential of 2D material junctions in nanotechnology, energy storage, and sustainable energy solutions, paving the way for high- performance photocatalysts and advanced electrochemical devices.
