Photocatalytic Activity Enhancement of Anatase/Rutile‐Mixed Phase TiO2 Nanoparticles Annealed with Low‐Temperature O2 Plasma
Photocatalytic Activity Enhancement of Anatase/Rutile‐Mixed Phase TiO2 Nanoparticles Annealed with Low‐Temperature O2 Plasma
复制标题
低温 O2 等离子体退火增强锐钛矿/金红石混合相 TiO2 纳米粒子的光催化活性
DOI：
10.1002/pssa.202100536
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发表时间：
2021
期刊：
影响因子：
--
通讯作者：
Mukai Takashi
中科院分区：
文献类型：
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作者：
Kawakami Retsuo;Mimoto Yuki;Yanagiya Shin-ichiro;Shirai Akihiro;Niibe Masahito;Nakano Yoshitaka;Mukai Takashi
通过与环境空气中退火的纳米TiO 2进行比较，阐明了低温O2等离子体退火的金红石/金红石混合相纳米TiO 2的光分解和光杀菌活性。与未处理的样品相比，等离子体辅助退火的样品不仅在紫外光照射下，而且在可见光照射下的光催化活性都大大增强。空气退火样品的光催化活性在紫外光照射下没有增强，但在可见光照射下增强。由于等离子体辅助退火（PAA）而增强的光催化活性源于增加的光激发载流子浓度。从PAA诱导的特征因子讨论了这种增强。PAA促进了向半导体的相变，直接有助于延长光激发载流子的寿命。PAA引入更多氧空位，有助于捕获更多光生电子。PAA还引入了更多吸附在表面上的桥接/末端氧基团，增加了向上的能带弯曲、表面处的耗尽层宽度以及从金红石到金红石的电荷转移。这两种引入有助于促进光激发载流子的分离。此外，PAA还降低了TiO 2纳米粒子的聚集体尺寸，从而增加了光吸收。光激发载流子通过桥氧/端氧基团产生更多的活性氧物种也将增强光催化活性。
Photodecomposition and photobactericidal activities of anatase/rutile‐mixed phase TiO2nanoparticles annealed with low‐temperature O2plasma are clarified by comparing them with those annealed in ambient air. The photocatalytic activities of plasma‐assisted‐annealed sample greatly enhance as compared with the untreated sample, under not only UV irradiation but also visible‐light irradiation. The photocatalytic activities of air‐annealed samples do not enhance under UV irradiation but enhance under visible‐light irradiation. The enhanced photocatalytic activities due to the plasma‐assisted annealing (PAA) originate from the increased photoexcited carrier concentration. This enhancement is discussed from PAA‐induced characteristic factors. PAA facilitates the phase transformation to anatase, contributing directly to extending the photoexcited carrier lifetime. PAA introduces more oxygen vacancies, contributing to trapping more photogenerated electrons. PAA also introduces more bridging/terminal oxygen groups adsorbed on the surface, increasing the upward band‐bending, the depletion layer width at the surface, and the charge transfer from rutile to anatase. These two introductions contribute to facilitating the separation of photoexcited carriers. Furthermore, PAA reduces the aggregate size of TiO2nanoparticles formed on the surface, contributing to increasing optical absorptions. More reactive oxygen species produced from the bridging/terminal oxygen groups by the photoexcited carriers will also enhance the photocatalytic activities.