title: In-Situ-Reduced Synthesis of Ti³⁺ Self-Doped TiO₂/g-C₃N₄ Heterojunctions with High Photocatalytic Performance under LED Light Irradiation.
abstract: A simple one-step calcination route was used to prepare Ti(3+) self-doped TiO2/g-C3N4 heterojunctions by mixture of H2Ti3O7 and melamine. X-ray diffraction (XRD), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), electron spin resonance (ESR) spectroscopy, and UV-Vis diffuse reflectance spectroscopy (UV-vis DRS) technologies were used to characterize the structure, crystallinity, morphology, and chemical state of the as-prepared samples. The absorption of the prepared Ti(3+) self-doped TiO2/g-C3N4 heterojunctions shifted to a longer wavelength region in comparison with pristine TiO2 and g-C3N4. The photocatalytic activities of the heterojunctions were studied by degrading methylene blue under a 30 W visible-light-emitting diode irradiation source. The visible-light photocatalytic activities enhanced by the prepared Ti(3+) self-doped TiO2/g-C3N4 heterojunctions were observed and proved to be better than that of pure TiO2 and g-C3N4. The photocatalysis mechanism was investigated and discussed. The intensive separation efficiency of photogenerated electron-hole in the prepared heterojunction was confirmed by photoluminescence (PL) spectra. The removal rate constant reached 0.038 min(-1) for the 22.3 wt % Ti(3+) self-doped TiO2/g-C3N4 heterojunction, which was 26.76 and 7.6 times higher than that of pure TiO2 and g-C3N4, respectively. The established heterojunction between the interfaces of TiO2 nanoparticles and g-C3N4 nanosheets as well as introduced Ti(3+) led to the rapid electron transfer rate and improved photoinduced electron-hole pair's separation efficiency, resulting in the improved photocatalytic performance of the Ti(3+) self-doped TiO2/g-C3N4 heterojunctions.
authors: †College of Chemistry and Materials Science, Ludong University, Yantai 264025, China.
authors: Kai
authors: K
authors: Li
authors: †College of Chemistry and Materials Science, Ludong University, Yantai 264025, China.|‡State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China.
authors: Shanmin
authors: S
authors: Gao
authors: †College of Chemistry and Materials Science, Ludong University, Yantai 264025, China.
authors: Qingyao
authors: Q
authors: Wang
authors: †College of Chemistry and Materials Science, Ludong University, Yantai 264025, China.
authors: Hui
authors: H
authors: Xu
authors: ‡State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China.
authors: Zeyan
authors: Z
authors: Wang
authors: ‡State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China.
authors: Baibiao
authors: B
authors: Huang
authors: ‡State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China.
authors: Ying
authors: Y
authors: Dai
authors: §Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States.
authors: Jun
authors: J
authors: Lu
keywords: LED light source; Ti3+ self-doped; TiO2/g-C3N4 heterojunctions; visible-light photocatalytic