Gliding Arc Plasma Induced One‐Step Millisecond Synthesis of Highly Crystalline Mesoporous TiO₂ Homojunctions for Robust Photocatalytic H₂ Production

One of the major challenges in photocatalytic hydrogen production lies in the charge separation and transfer. Herein, a one-step millisecond synthesis of highly crystalline mesoporous TiO₂ homojunction nanostructures through the gliding arc plasma is developed toward efficient photocatalytic hydrogen production. The unique non-thermal plasma environment uniquely enables the concurrent attainment of high crystallinity, well-defined mesoporosity, and homojunction formation within millisecond. The synthesized TiO₂ predominantly comprises an anatase phase (≈80%), with the remainder being a rutile phase. By varying the gas flow rate, there is a noticeable transition in particle morphology from spherical to non-spherical, accompanied by a gradual reduction in particle size. The mechanism underlying the one-step synthesis of mesoporous TiO₂ homojunctions through gliding arc plasma has been elucidated using in situ emission spectroscopy and band-pass filter imaging. The optimized TiO₂ homojunctions exhibited exceptional photocatalytic hydrogen production rate, 4.32 mmol g^-1 h^-1 under simulated solar light irradiation, corresponding excellent stability, and reusability. This work not only demonstrates the potential of gliding arc plasma technology for advanced material synthesis but also opens new avenues for the scalable production of high-performance photocatalysts for sustainable hydrogen production.