Low-temperature strategy for vapor phase hydrothermal synthesis of C\N\S-doped TiO2 nanorod arrays with enhanced photoelectrochemical and photocatalytic activity

• Published in: Journal of industrial and engineering chemistry (Seoul, Korea) Vol. 98; pp. 130 - 139
• Main Authors: Yu, Hai, Zhang, Miao, Wang, Yanfen, Lv, Janguo, Liu, Yanmei, He, Gang, Sun, Zhaoqi
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 25.06.2021; 한국공업화학회
• Subjects: C/N/S-TiO2; Low-temperature strategy; One-step synthesis non-metal doping; Photoelectrochemical activity; Vapor phase hydrothermal method; 화학공학; Vapor phase hydrothermal method; Low-temperature strategy; C/N/S-TiO2; Photoelectrochemical activity; One-step synthesis non-metal doping
• ISSN: 1226-086X; 1876-794X
• DOI: 10.1016/j.jiec.2021.03.021

A material with high photocatalytic activity was synthesized using ternary C/N/S-doped TiO2 nanorod array (TiO2); this was done using a practical and straightforward vapor-phase hydrothermal (VPH) method at a low temperature. The favorable sunlight-driven photocatalytic activity is probably due to the synergistic effect of C/N/S-doping, which shifts the valence band maximum of TiO2 upward. It is noteworthy that VPH is a very effective strategy for fabricating semiconductors doped with multiple nonmetallic elements. [Display omitted] In this study, a material with high photocatalytic activity was synthesized using ternary C/N/S-doped TiO2 nanorod array (TiO2); this was done using a practical and straightforward vapor-phase hydrothermal (VPH) method at a low temperature. The effect of C/N/S content on TiO2 morphology, optical, photocatalytic and photoelectrochemical (PCE) properties of the material was investigated by varying the quality of thiourea. C/N/S-TiO2 reduced the bonding rate of electron-hole pairs and enhances visible light absorption, photocatalytic, and PCE properties. The C/N/S doping could significantly adjust the absorption cut-off wavelengths (407−602nm) and shorten the bandgap (3.04−2.18eV) of TiO2. Under simulated sunlight, 8-C/N/S-TiO2 had the highest photocatalytic efficiency of 97.6% for methylene blue (MB) in 150min with a rate constant of 0.0192min−1, which is approximately four times that of TiO2 (0.005min−1). The 8-C/N/S-TiO2 photoelectrode had the lowest transfer resistance for interfacial charges and highest transient photocurrent of 33.5μA/cm2, which is five times higher than that of TiO2 (6.6μA/cm2). The 8-C/N/S-TiO2 exhibits the most extensive PCE behavior as a photoelectrode, and has a current density of 38.2mA/cm2 at 2.5VRHE, which is about two times higher than TiO2 (19.1mA/cm2). The favorable sunlight-driven photocatalytic activity is probably due to the synergistic effect of C/N/S-doping, which shifts the valence band maximum of TiO2 upward. This provides new ideas for future solar cells that can use dye-sensitized TiO2 nanorod arrays as photoanodes. It is noteworthy that VPH is a very effective strategy for fabricating semiconductors doped with multiple nonmetallic elements.