Preparation of low-density tantalum oxide aerogels with tunable morphology for photocatalysis

• Published in: Journal of solid state chemistry Vol. 337; p. 124825
• Main Authors: Wu, Zhiqing, Huang, Chuanqun, Yang, Ruizhuang, Zhong, Minglong, Luo, Xuan
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01.09.2024
• Subjects: Aerogels; Photocatalysis; Sol-gel methodology; Tantalum oxides; Thermal annealing; Aerogels; Sol-gel methodology; Thermal annealing; Photocatalysis; Tantalum oxides
• ISSN: 0022-4596; 1095-726X
• DOI: 10.1016/j.jssc.2024.124825

Aerogel has the advantages of ultra-low density, high porosity and large surface area, and has wide application prospects in thermal insulation, energy storage, biomedicine, acoustics and other fields. However, there are few reports on the preparation of high-purity and low-density Ta2O5 aerogels, which limits their wide applications. In this work, we report a facile preparation of low-density bulk Ta2O5 aerogels using a two-step epoxide-induced sol-gel process with tantalum ethoxide as precursor. The minimum apparent density of aerogel prepared by this method is 35 mg/cm3. Effects of thermal annealing on morphological characteristics, crystalline phase, thermal stability, as well as the chemical composition of the Ta2O5 aerogels were studied. The X-ray photoelectron spectroscopy (XPS) and electron paramagnetic resonance (EPR) results confirmed the existence of oxygen-defects in the Ta2O5 aerogels. The Ta2O5 aerogel annealing at 250 °C exhibit the most preferable photocatalytic performance of RhB degradation due to more oxygen-defects. Oxygen defects in Ta2O5 aerogel introduce defect levels in its band gap, so light absorption and charge separation capabilities will be greatly improved. This dopant-free, stable Ta2O5 aerogel catalyst may have applications in the field of photocatalysis. The minimum apparent density of aerogel prepared by this method is only 35 mg/cm3. Preliminary study on photocatalysis shows that the Ta2O5 aerogel annealed at 250 °C exhibit the most preferable photocatalytic degradation of RhB due to more oxygen-defects. [Display omitted] •An effective preparation method of low-density Ta2O5 aerogels is established.•The Ta2O5 aerogel annealed at 250 oC exhibits the best photocatalytic performance for RhB degradation.•The formation of oxygen defects effectively reduces the band gap of Ta2O5 aerogel.