Han Bing, Yu Siqi, Zhao Dian, Lou Yunchao, Gao Jiayang, Liu Zhe, Wang Zhiyu, Qian Guodong
State Key Laboratory of Silicon Materials, Department of Materials Science and Engineering, Zhejiang University Hangzhou 310027 China
Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, College of Chemistry and Life Sciences, Zhejiang Normal University Jinhua 321004 China.
RSC Adv. 2020 Oct 22;10(64):38798-38804. doi: 10.1039/d0ra06107g. eCollection 2020 Oct 21.
Intermediate-band semiconductors perform functions similar to natural photosynthesis by combining two photons to achieve a higher electron excitation. In this study, a strategy was developed to prepare a high oxygen-doped CeF (CeF-O) nanomaterial that exhibits photocatalytic activity under visible/NIR light for the first time. The homogeneous doping oxygen atoms were verified to efficiently modify the band structure of CeF. DFT calculation predicted the formation of an intermediate band within CeF upon homogeneous doping of O at interstitial sites. The interaction between F and O atoms generates an intermediate band, which divides the total bandgap of CeF-O into two sub-bandgaps at about 1.7 eV and 2.9 eV, enabling CeF-O photocatalysis under visible light and NIR light. Reflectance spectra evidenced that the same bandgaps exist. The photocatalytic activities of CeF-O were tested by wavelength-controlled light. The rate constants of TC-HCl photodegrading under visible/NIR light are 12.85 × 10 min and 1.28 × 10 min, respectively. The two-step electron transfer was also obviously confirmed in visible-light photocatalysis. In conclusion, the high oxygen doping builds a more applicable band structure of CeF-O for photocatalytic performance, charge transfer and special light response for visible/NIR light.
中间带半导体通过结合两个光子以实现更高的电子激发来执行类似于自然光合作用的功能。在本研究中，开发了一种策略来制备首次在可见光/近红外光下表现出光催化活性的高氧掺杂CeF（CeF-O）纳米材料。已证实均匀掺杂的氧原子有效地改变了CeF的能带结构。密度泛函理论计算预测，在间隙位置均匀掺杂O后，CeF内部会形成一个中间带。F和O原子之间的相互作用产生一个中间带，该中间带将CeF-O的总带隙分为两个约为1.7 eV和2.9 eV的子带隙，从而使CeF-O能够在可见光和近红外光下进行光催化。反射光谱证明存在相同的带隙。通过波长控制光测试了CeF-O的光催化活性。在可见光/近红外光下TC-HCl光降解的速率常数分别为12.85×10⁻³ min⁻¹和1.28×10⁻³ min⁻¹。在可见光光催化中也明显证实了两步电子转移。总之，高氧掺杂为CeF-O构建了更适用于光催化性能、电荷转移以及对可见光/近红外光的特殊光响应的能带结构。
