Presentation Information
[21a-A311-4]Exploring Photo-Piezocatalysis in Heterostructured Barium Titanate and Titanium Dioxide: Insights from Photo-Triggered Contact Potential Differences
〇(D)JiaMao Chang1, TingHan Lin1, YinHsuan Chang1, KaiChi Hsiao1, MingChung Wu1 (1.Chang Gung Univ.)
Keywords:
Piezocatalysis,Barium titanate,Kelvin probe force microscopy
Pollutants perpetually generated by various industries intensify the burden on the environment and progressively damage our living spaces. The combination of photocatalysis and piezocatalysis presents an intriguing technique for achieving pollutant degradation and potential in versatility and energy efficiency. In this study, we synthesized a nanosized photo-piezocatalyst by incorporating titanium dioxide (TiO2) with barium titanate (BaTiO3) using an in situ hydrothermal method. As the reaction temperature increased, BaTiO3 gradually grew onto the TiO2 nanoparticle, promoting a phase transition in the crystal structure. At a critical temperature of 120°C, both the primary crystalline structures of BaTiO3 and TiO2 coexisted, revealing a heterostructure evident in microstructure observation. When compared to pristine TiO2 and BaTiO3, the BaTiO3-TiO2 demonstrated superior degradation activity towards methyl orange dye under both illumination and ultrasonic vibration. This resulted in a reaction rate constant of 0.01326 min-1. To understand the enhancement mechanism of photo-assisted piezocatalysis, we used an innovative photo-induced in-situ Kelvin probe analyzer to measure the contact potential difference (CPD) of the material. Tests on the optimal BaTiO3-TiO2 photo-piezocatalyst revealed that the change in CPD of BaTiO3-TiO2 exhibits a delayed behavior under continuous UV LED illumination in both short-term and long-term illumination switch tests. We infer that the hysteresis of CPD could be caused by photo-induced charge driven by TiO2, which reduces the polarization of BaTiO3. This phenomenon likely contributes to interfacial charge migration under photo and ultrasonic vibration, possibly extending the charge life and maintaining a sufficient surface charge concentration for radical generation.