Yu Fei, Wang Changhua, Li Yingying, Ma He, Wang Rui, Liu Yichun, Suzuki Norihiro, Terashima Chiaki, Ohtani Bunsho, Ochiai Tsuyoshi, Fujishima Akira, Zhang Xintong
Key Laboratory of UV-Emitting Materials and Technology of Chinese Ministry of Education Northeast Normal University Changchun 130024 China.
Photocatalysis International Research Center Research Institute for Science & Technology Tokyo University of Science 2641 Yamazaki Noda Chiba 278-8510 Japan.
Adv Sci (Weinh). 2020 Jun 11;7(16):2000204. doi: 10.1002/advs.202000204. eCollection 2020 Aug.
Colored wide-bandgap semiconductor oxides with abundant mid-gap states have long been regarded as promising visible light responsive photocatalysts. However, their catalytic activities are hampered by charge recombination at deep level defects, which constitutes the critical challenge to practical applications of these oxide photocatalysts. To address the challenge, a strategy is proposed here that includes creating shallow-level defects above the deep-level defects and thermal activating the migration of trapped electrons out of the deep-level defects via these shallow defects. A simple and scalable solution plasma processing (SPP) technique is developed to process the presynthesized yellow TiO with numerous oxygen vacancies (Ov), which incorporates hydrogen dopants into the TiO lattice and creates shallow-level defects above deep level of Ov, meanwhile retaining the original visible absorption of the colored TiO. At elevated temperature, the SPP-treated TiO exhibits a 300 times higher conversion rate for CO reduction under solar light irradiation and a 7.5 times higher removal rate of acetaldehyde under UV light irradiation, suggesting the effectiveness of the proposed strategy to enhance the photoactivity of colored wide-bandgap oxides for energy and environmental applications.
具有丰富带隙中间态的有色宽带隙半导体氧化物长期以来一直被视为有前景的可见光响应光催化剂。然而，它们的催化活性受到深能级缺陷处电荷复合的阻碍，这对这些氧化物光催化剂的实际应用构成了关键挑战。为应对这一挑战，本文提出了一种策略，包括在深能级缺陷上方创建浅能级缺陷，并通过这些浅缺陷热激活被困电子从深能级缺陷中迁移出来。开发了一种简单且可扩展的溶液等离子体处理（SPP）技术来处理预先合成的具有大量氧空位（Ov）的黄色TiO，该技术将氢掺杂剂引入TiO晶格，并在Ov的深能级上方创建浅能级缺陷，同时保留有色TiO原有的可见光吸收。在升高的温度下，经SPP处理的TiO在太阳光照射下对CO还原的转化率高出300倍，在紫外光照射下对乙醛的去除率高出7.5倍，这表明所提出的策略对于增强有色宽带隙氧化物在能源和环境应用中的光活性是有效的。
