Chen Jian-An, Tsai Shu-Min, Hong Yi-You, Shih Pin-Jyun, Liu Day-Shan
Institute of Electro-Optical and Materials Science, National Formosa University, Huwei 63201, Taiwan.
Materials (Basel). 2025 Jun 24;18(13):2993. doi: 10.3390/ma18132993.
In this study, the surface photocatalytic activity of an anatase-titanium oxide (TiO) film was modified by a thin copper (Cu) layer with the subsequential oxidation annealing process. Through this simple annealing process, the photocatalytic activity of the TiO/Cu structure to decompose the methylene blue solution and inhibit the growth of . could be optimized. With the help of a study on the conductive type required for the oxidation of a single Cu layer, an nanocomposite heterojunction was realized, as this contact system anneals at temperatures of 350 °C and 450 °C. An extra electrical field at the contact interfaces that was be beneficial for separating the photo-generated electron-hole pairs (EHPs) under UV light irradiation was built. The built-in electrical field led to an increase in the structural photocatalytic activity. Moreover, as the -type cuprous oxide (-CuO) structure oxidized by the annealed Cu layer could provide a high conduction band that is offset when in contact with the TiO film, the photogenerated EHPs on the TiO surface could be separated more effectively. Accordingly, the 350 °C-annealed sample, abundant in the nanocomposite TiO/CuO heterojunction which could significantly retard the recombination of photo-generated carriers, corresponded to an increase of about 38% in the photocatalytic activity as compared with the single TiO film.
在本研究中，通过后续氧化退火工艺，用薄铜（Cu）层对锐钛矿型二氧化钛（TiO₂）薄膜的表面光催化活性进行了改性。通过这种简单的退火工艺，可以优化TiO₂/Cu结构对亚甲基蓝溶液的光催化分解活性以及抑制其生长的能力。借助对单层Cu氧化所需导电类型的研究，实现了一种纳米复合异质结，因为这种接触系统在350℃和450℃的温度下退火。在紫外光照射下，在接触界面处建立了一个有利于分离光生电子-空穴对（EHPs）的额外电场。该内建电场导致结构光催化活性增加。此外，由于经退火的Cu层氧化形成的p型氧化亚铜（p-Cu₂O）结构可以提供一个与TiO₂薄膜接触时发生偏移的高导带，TiO₂表面的光生EHPs可以更有效地分离。因此，在350℃退火的样品中富含纳米复合TiO₂/Cu₂O异质结，这可以显著延迟光生载流子的复合，与单一TiO₂薄膜相比，其光催化活性提高了约38%。
