Titanium dioxide (TiO₂₎ photoelectrodes that offer high light absorption and efficient charge separation hold great promise in photocatalysis. In this study, a simple and controllable method for fabricating hierarchical TiO_2−x photoelectrodes by coupling femtosecond laser processing and anodization is proposed. The fabricated photoelectrodes consist of microcones (approximately 150,000 per square centimetre) covered with large quantities of nanotubes. The hierarchical structures possess significant light-trapping effect, meanwhile, oxygen vacancies were simultaneously introduced through laser processing with anodization, which can be attributed to the fs-laser mediated lattice phase transformation (polycrystalline and amorphous layer) of titanium. With the synergistic effects of hierarchical structures and oxygen vacancies, the hierarchical TiO_2−x electrode exhibited a narrowed bandgap (1.95 eV) and remarkable light absorption. Especially under visible light, this photoelectrode demonstrated 15-fold photocurrent enhancement and double the usual photodegradation rate of methylene blue. This morphological control and defect introduction method may be extensively used in efficient solar utilisation.

提供高光吸收和有效电荷分离的二氧化钛（TiO _2）光电极在光催化中具有广阔的前景。在这项研究中，一种简单且可控制的制造分层TiO _{2- x的方法}飞秒激光处理与阳极氧化相结合提出了一种光电极。制成的光电极由覆盖大量纳米管的微锥（每平方厘米约150,000个）组成。分层结构具有显着的光俘获效果，同时，通过激光处理和阳极氧化同时引入了氧空位，这可以归因于钛的fs-激光介导的晶格相变（多晶和非晶层）。借助分层结构和氧空位的协同效应，分层TiO _{2- x}电极显示出较窄的带隙（1.95 eV）和显着的光吸收。尤其是在可见光下，这种光电极显示出15倍的光电流增强，是亚甲基蓝通常光降解速率的两倍。这种形态控制和缺陷引入方法可广泛用于有效的太阳能利用中。