biostudies-literatureCui ZMinistry of Education of the People's Republic of ChinaNational Natural Science Foundation of China27121-27128https://www.ebi.ac.uk/biostudies/studies/S-EPMC8529652biostudies-literatureUnknown6(41)In this work, the photocatalytic performance enhancement of hydrothermally prepared TiO<sub>2</sub> was achieved by facile vacuum annealing treatment. Calcination of TiO<sub>2</sub> powder in air (CA-TiO<sub>2</sub>) maintained its white color, while gray powder was obtained when the annealing was performed under vacuum (CV-TiO<sub>2</sub>). Fourier transform infrared, total organic carbon, X-ray photoelectron spectroscopy, and electron paramagnetic resonance analyses proved that vacuum annealing transformed ethanol adsorbed on the surface of TiO<sub>2</sub> into carbon-related species accompanied by the formation of surface oxygen vacancies (Vo). The residual carbon-related species on the surface of CV-TiO<sub>2</sub> favored its adsorption of organic dyes. Compared with TiO<sub>2</sub> and CA-TiO<sub>2</sub>, CV-TiO<sub>2</sub> exhibited an improved charge carrier separation with surface Vo as trapping sites for electrons. Vacuum annealing-induced improvement of crystallinity, enhancement of adsorption capacity, and formation of surface Vo contributed to the excellent photocatalytic activity of CV-TiO<sub>2</sub>, which was superior to that of commercial TiO<sub>2</sub> (P25, Degussa). Obviously, vacuum annealing-triggered decomposition of ethanol played an important role in the modification of TiO<sub>2</sub>. In the presence of ethanol, vacuum annealing was also suitable for the introduction of Vo into P25. Therefore, the current work offers an easy approach for the modification of TiO<sub>2</sub> to enhance its photocatalytic performance by facile vacuum annealing in the presence of ethanol.ACS omegaFacile Vacuum Annealing-Induced Modification of TiO<sub>2</sub> with an Enhanced Photocatalytic Performance.PMC8529652lzujbky-2020-kb06lzujbky-2021-sp2912005086Zhao MPan DQue XCui ZGhazzal MNColbeau-Justin CWu WWang JXu YfalseFacile Vacuum Annealing-Induced Modification of TiO<sub>2</sub> with an Enhanced Photocatalytic Performance.In this work, the photocatalytic performance enhancement of hydrothermally prepared TiO<sub>2</sub> was achieved by facile vacuum annealing treatment. Calcination of TiO<sub>2</sub> powder in air (CA-TiO<sub>2</sub>) maintained its white color, while gray powder was obtained when the annealing was performed under vacuum (CV-TiO<sub>2</sub>). Fourier transform infrared, total organic carbon, X-ray photoelectron spectroscopy, and electron paramagnetic resonance analyses proved that vacuum annealing transformed ethanol adsorbed on the surface of TiO<sub>2</sub> into carbon-related species accompanied by the formation of surface oxygen vacancies (Vo). The residual carbon-related species on the surface of CV-TiO<sub>2</sub> favored its adsorption of organic dyes. Compared with TiO<sub>2</sub> and CA-TiO<sub>2</sub>, CV-TiO<sub>2</sub> exhibited an improved charge carrier separation with surface Vo as trapping sites for electrons. Vacuum annealing-induced improvement of crystallinity, enhancement of adsorption capacity, and formation of surface Vo contributed to the excellent photocatalytic activity of CV-TiO<sub>2</sub>, which was superior to that of commercial TiO<sub>2</sub> (P25, Degussa). Obviously, vacuum annealing-triggered decomposition of ethanol played an important role in the modification of TiO<sub>2</sub>. In the presence of ethanol, vacuum annealing was also suitable for the introduction of Vo into P25. Therefore, the current work offers an easy approach for the modification of TiO<sub>2</sub> to enhance its photocatalytic performance by facile vacuum annealing in the presence of ethanol.2021-01-01T00:00:00Z2021 Oct2025-04-25T22:06:00.415Z2025-04-06T08:56:31.935ZS-EPMC85296523469313210.1021/acsomega.1c03762