Defect-rich hierarchical sponge-like TiO₂ nanoparticles were successfully synthesized via the combined one-step hydrothermal method and chemical reduction approach. SEM and TEM images showed their porous structure densely packed with even smaller TiO₂ particles, while photocatalytic results manifested their superior photocatalytic performance and high stability. The RhB solution (10 ppm) could be absolutely degraded in 60 min, and the degradation rate was twice that of the sample without the treatment by NaBH₄. Besides, the TC solution (10 ppm) could be removed by 74.3% in 20 min. PEC measurements also displayed that the photoelectrode based on such defectrich TiO₂ nanoparticles had small resistance and improved charge transfer rate. The improved performance can be assigned to rich defects and phase junctions, which was supported by characterization results. The presence of rich defects and phase junctions could not only promote the separation of photogenerated charge carriers, but also accelerate the electron transfer, beneficial for both the photocatalytic and the PEC performance. It is expected that the obtained hierarchical sponge-like TiO₂ nanoparticles with rich defects have great potential for photocatalytic applications.

通过一步水热法和化学还原法相结合，成功地合成了多缺陷的分层海绵状TiO ₂纳米粒子。SEM和TEM图像显示其多孔结构致密地堆积着甚至更小的TiO ₂颗粒，而光催化结果表明它们具有优异的光催化性能和高稳定性。RhB溶液（10 ppm）可以在60分钟内完全降解，并且降解速率是未经NaBH ₄处理的样品的两倍。此外，TC溶液（10 ppm）可以在20分钟内去除74.3％。PEC测量还显示，基于这种缺陷丰富的TiO ₂的光电极纳米粒子具有较小的电阻并改善了电荷转移速率。可以将改进的性能分配给丰富的缺陷和相结，这得到了表征结果的支持。丰富的缺陷和相结的存在不仅可以促进光生载流子的分离，而且可以促进电子转移，有利于光催化和PEC性能。预期获得的具有丰富缺陷的分级海绵状TiO ₂纳米颗粒具有光催化应用的巨大潜力。