Li Wenjuan, Liang Robert, Zhou Norman Y, Pan Zihe
College of Art, Taiyuan University of Technology, 209 University Avenue, Jinzhong, Shanxi 030600, China.
Department of Mechanical and Mechanics, Waterloo Institute for Nanotechnology, University of Waterloo, 200 University AVE West, Waterloo, ON, Canada N2L 3G1.
ACS Omega. 2020 Apr 22;5(17):10042-10051. doi: 10.1021/acsomega.0c00504. eCollection 2020 May 5.
In this work, C-doped TiO nanorods were synthesized through doping carbon black into hydrothermally synthesized solid-state TiO nanowires (NWs) via calcination. The effects of carbon content on the morphology, phase structure, crystal structure, and photocatalytic property under both UV and solar light by the degradation of methylene blue (MB) were explored. Besides, the photoelectrochemical property of C-TiO was systematically studied to illustrate the solar light degradation mechanism. After doping with C, TiO NWs were reduced into nanorods and the surface became rough with dispersed particles. Results showed that C has successfully entered the TiO lattice, resulting in the lattice distortion, reduction of band gap, and the formation of C-Ti-O, which expands TiO to solar light activation. Comparing with P25 and anatase TiO NWs, doping with carbon black showed much higher UV light and solar light photocatalytic activity. The photocatalytic activity was characterized via the degradation of MB, showing that was 0.0328 min under solar light, while 0.1634 min under UV irradiation. The main free radicals involved in methylene blue degradation are H and OH. Doping with carbon black led to the reduction of photocurrent in a long-term operation, while C-doping reduced the electron-hole recombination and enhanced the carrier migration.
在本工作中，通过将炭黑掺杂到水热合成的固态TiO纳米线（NWs）中并进行煅烧，合成了C掺杂的TiO纳米棒。通过亚甲基蓝（MB）的降解，研究了碳含量对紫外光和太阳光下的形貌、相结构、晶体结构及光催化性能的影响。此外，系统研究了C-TiO的光电化学性质以阐明太阳光降解机理。掺杂C后，TiO NWs还原为纳米棒，表面变得粗糙且有分散的颗粒。结果表明，C成功进入TiO晶格，导致晶格畸变、带隙减小以及C-Ti-O的形成，从而使TiO扩展到太阳光激活范围。与P25和锐钛矿型TiO NWs相比，掺杂炭黑表现出更高的紫外光和太阳光光催化活性。通过MB的降解对光催化活性进行表征，结果表明在太阳光下为0.0328 min，而在紫外光照射下为0.1634 min。参与亚甲基蓝降解的主要自由基是H和OH。掺杂炭黑导致长期运行中光电流降低，而C掺杂减少了电子-空穴复合并增强了载流子迁移。
