Qi Lei, Wang Mei, Xue Jianbin, Zhang Qiyuan, Chen Feng, Liu Qianqian, Li Wanfei, Li Xinheng
The State Key Laboratory for Oxo Synthesis and Selective Oxidation, Suzhou Research Institute of LICP, Lanzhou Institute of Chemical Physics (LICP), Chinese Academy of Sciences, Lanzhou, 730000, P. R. China.
University of Chinese Academy of Sciences, Beijing, 100049, P. R. China.
Chemistry. 2021 Oct 21;27(59):14638-14644. doi: 10.1002/chem.202102120. Epub 2021 Sep 20.
Photocatalytic Z or S scheme merits higher redox potentials and faster charge separation. However, heterostructure photocatalysts with band gaps of bulk materials often have a type I band structure leading to poor photocatalytic activity. In view of this, we report simultaneous tuning of band gaps of Cu O and TiO , where quantum dot Cu O nanoparticles were formed on doped TiO with Ti . The reduced size of Cu O made its conduction band more negative, whereas the introduction of Ti made the absorption edge red shift to the visible light region. The as-formed heterostructure enabled an S-Scheme mechanism with remarkable activity and stability for visible light photodegradation of 4-chlorophenol (4-CP). The as-obtained photocatalysts' activity demonstrated ca. 510-fold increase as compared to individual ones and a mechanical blend. The as-obtained photocatalysts maintained over 80 % for 5 cycles and 2 months exposure to O did not decrease the degradation rate. ESR characterization and scavenger experiments proved the S-Scheme mechanism.
光催化Z型或S型体系具有更高的氧化还原电位和更快的电荷分离速度。然而，具有体材料带隙的异质结构光催化剂通常具有I型能带结构，导致光催化活性较差。鉴于此，我们报道了对CuO和TiO带隙的同时调控，其中在Ti掺杂的TiO上形成了量子点CuO纳米颗粒。CuO尺寸的减小使其导带更负，而Ti的引入使吸收边红移至可见光区域。所形成的异质结构实现了S型机制，对4-氯苯酚（4-CP）的可见光光降解具有显著的活性和稳定性。所获得的光催化剂的活性与单独的光催化剂和机械混合物相比提高了约510倍。所获得的光催化剂在5个循环中保持超过80%的活性，暴露于O₂ 2个月也未降低降解速率。电子自旋共振（ESR）表征和清除剂实验证明了S型机制。
