Hydrothermal preparation of Nb-doped NaTaO3 with enhanced photocatalytic activity for removal of organic dye

• Published in: Chinese journal of chemical engineering Vol. 46; no. 6; pp. 142 - 149
• Main Authors: Zhou, Hao, Yin, Qi
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.06.2022; State Key Laboratory of Clean Energy Utilization,Zhejiang University,Hangzhou 310027,China
• Subjects: Methylene blue; NaTaO3; Photocatalytic degradation; NaTaO3; Photocatalytic degradation; Methylene blue
• ISSN: 1004-9541; 2210-321X
• DOI: 10.1016/j.cjche.2021.05.037

[Display omitted] The construction of efficient photocatalysts has received much attention in wastewater treatment. In this study, Nb-doped NaTaO3 was prepared with different doping ratio by a facile hydrothermal method. The prepared catalysts were analyzed by X-ray diffraction, scanning electron microscopy, Brunauer-Emmett-Teller (BET) theory, ultraviolet–visible diffuse reflectance spectroscopy. Then the synthesized catalysts were employed to degrade a model pollutant, methylene blue (MB), under a 250 W mercury lamp. The characterization tests confirm that Nb was successfully doped into the crystal structure of NaTaO3 and the modified NaNbxTa1−xO3 (x is the doping ratio; x = 0.25, 0.5, 0.75) samples were formed, which were in regular cubic shapes just like pure NaTaO3. The synthesized NaNbxTa1−xO3 (x = 0.25, 0.5, 0.75) had improved specific surface area and narrowed band gaps compared with pure NaTaO3. In photocatalytic degradation experiments, NaNb0.75Ta0.25O3 presented the best photocatalytic activity ascribed to the narrow band gap and the high surface area, degradating 95.7% of MB after 180 min of reaction, which was even twice the ability of pure NaTaO3. Besides, the effects of possible inorganic anions and cations in wastewater on photocatalytic degradation were investigated. Electron spin resonance (ESR) tests and capture experiments were also conducted and a possible photocatalytic mechanism was proposed. This work provides a direction for constructing superior NaTaO3-based photocatalysts to be widely utilized in environmental protection.