Center of Excellence on Catalysis and Catalytic Reaction Engineering, Department of Chemical Engineering, Faculty of Engineering, Chulalongkorn University, Bangkok, 10330, Thailand.
Chemical and Petroleum Engineering Department, UAE University, P.O. Box 15551, Al Ain, United Arab Emirates; Chemical Reaction Engineering Group (CREG), School of Chemical and Energy Engineering, Universiti Teknologi Malaysia, 81310, UTM, Johor Bahru, Johor, Malaysia.
Chemosphere. 2022 Feb;289:133170. doi: 10.1016/j.chemosphere.2021.133170. Epub 2021 Dec 4.
This study investigates the facile fabrication of interfacial defects assisted amorphous TiO nanotubes arrays (am-TNTA) for promoting gas-phase CO photoreduction to methane. The am-TNTA catalyst was fabricated via a one-step synthesis, without heat treatment, by anodization of Titanium in Ethylene glycol-based electrolyte in a shorter anodizing time. The samples presented a TiO nanostructured array with a nanotubular diameter of 100 ± 10 nm, a wall thickness of 26 ± 5 nm, and length of 3.7 ± 0.3 μm, resulting in a specific surface of 0.75 m g. The am-TNTA presented prolonged chemical stability, a high exposed surface area, and a large number of surface traps that can reduce the recombination of the charge carriers. The am-TNTA showed promising photoactivity when tested in the CO reduction reaction with water under UV irradiation with a methane production rate of 14.0 μmol g h for a pure TiO material without any modification procedure. This enhanced photocatalytic activity can be explained in terms of surface defects of the amorphous structure, mainly OH groups that can act as electron traps for increasing the electron lifetime. The CO interacts directly with those traps, forming carbonate species, which favors the catalytic conversion to methane. The am-TNTA also exhibited a high stability during six reaction cycles. The photocatalytic activity, the significantly reduced time for synthesis, and high stability for continuous CH production make this nanomaterial a potential candidate for a sustainable CO reduction process and can be employed for other energy applications.
本研究通过简便的界面缺陷辅助法制备了非晶态 TiO 纳米管阵列（am-TNTA），以促进气相 CO 光还原为甲烷。am-TNTA 催化剂是通过一步合成在较短的阳极氧化时间内在乙二醇基电解质中对钛进行阳极氧化制备的，无需热处理。样品呈现出具有 100 ± 10nm 纳米管直径、26 ± 5nm 壁厚和 3.7 ± 0.3μm 长度的 TiO 纳米结构阵列，比表面积为 0.75m g。am-TNTA 具有良好的化学稳定性、高暴露表面积和大量表面陷阱，可以减少电荷载流子的复合。am-TNTA 在紫外光照射下的 CO 还原反应中与水反应时表现出良好的光活性，甲烷产率为 14.0μmol g h，而未经任何修饰的纯 TiO 材料的甲烷产率为 14.0μmol g h，这表明其具有良好的光催化活性。这种增强的光催化活性可以用非晶态结构的表面缺陷来解释，主要是 OH 基团可以作为电子陷阱，增加电子寿命。CO 直接与这些陷阱相互作用，形成碳酸盐物种，有利于催化转化为甲烷。am-TNTA 在六个反应循环中也表现出高稳定性。这种纳米材料具有较高的光催化活性、显著缩短的合成时间和连续 CH 4 生产的高稳定性，使其成为一种潜在的可持续 CO 还原过程的候选材料，并可用于其他能源应用。
