Abstract: Developing high-performance photoelectrodes is crucial for advancing solar energy conversion. This study aims to construct an efficient Schottky junction photoanode by integrating Ti3C2Tx MXene nanosheets with rutile TiO2 nanorod arrays (NRs) to synergistically enhance charge separation and light harvesting. The Ti3C2Tx/TiO2 composite was fabricated by spin-coating Ti3C2Tx nanosheets, known for their high conductivity and localized surface plasmon resonance (LSPR), onto hydrothermally grown TiO2 NRs. Material characterization techniques, including XRD, XPS, SEM, and TEM, confirmed the successful preparation of Ti3C2Tx and its uniform deposition on the TiO2. Photoelectrochemical (PEC) tests revealed that the optimized composite (MT-200) achieved a significant photocurrent density of 1.21 mA/cm2 under AM 1.5G illumination, which represents a 51.9% enhancement compared to pristine TiO2. This performance improvement is attributed to two primary factors. First, the intimate interface between Ti3C2Tx and TiO2 forms an effective Schottky junction, which significantly promotes the separation of photogenerated electron-hole pairs. Second, the intrinsic LSPR property of Ti3C2Tx endows the composite with plasmonic excitation capability. The associated photothermal effect locally elevates the temperature at the reaction interface, thereby further accelerating interfacial reaction kinetics and boosting charge carrier transport. This work demonstrates a promising strategy for enhanced PEC performance through the synergistic integration of Schottky junction and plasmonic effects in a Ti3C2Tx/TiO2 heterostructure.

Key words: Ti₃C₂T_x, Localized surface plasmon resonance; Schottky junction, Photoelectrochemical water splitting