Ji Myeongjun, Choa Yong-Ho, Lee Young-In
Department of Materials Science and Engineering, Seoul National University of Science and Technology, Seoul 01811, Republic of Korea.
Department of Materials Science and Chemical Engineering, Hanyang University, Ansan-si 15588, Republic of Korea.
Ultrason Sonochem. 2021 Jun;74:105557. doi: 10.1016/j.ultsonch.2021.105557. Epub 2021 Apr 15.
Black TiO has recently emerged as one of the most promising visible-light-driven photocatalysts, but current synthesis routes that require a reduction step are not compatible with cost-effective mass production and a relatively large particle such as microspheres. Herein, we demonstrate a simple, fast, cost-effective and scalable one-step process based on an ultrasonic spray pyrolysis for the synthesis of black TiO microspheres. The process utilizes an oxygen-deficient environment during the pyrolysis of titanium precursors to directly introduce oxygen vacancies into synthesized TiO products, and thus a reduction step is not required. Droplets of a titanium precursor solution were generated by ultrasound energy and dragged with continuous N flow into a furnace for the decomposition of the precursor and crystallization to TiO and through such a process spherical black TiO microspheres were obtained at 900 °C. The synthesized black TiO microsphere with trivalent titanium/oxygen vacancy clearly showed the variation of physicochemical properties compared with those of white TiO. In addition, the synthesized microspheres presented the superior photocatalytic activity for degradation of methylene blue under visible light irradiation. This work presents a new methodology for a simple one-step synthesis of black metal oxides microspheres with oxygen vacancies for visible-light-driven photocatalysts with a higher efficiency.
黑色二氧化钛最近已成为最有前途的可见光驱动光催化剂之一，但目前需要还原步骤的合成路线与具有成本效益的大规模生产以及相对较大的颗粒（如微球）不相容。在此，我们展示了一种基于超声喷雾热解的简单、快速、经济高效且可扩展的一步法，用于合成黑色二氧化钛微球。该过程在钛前驱体热解过程中利用缺氧环境，将氧空位直接引入合成的二氧化钛产物中，因此不需要还原步骤。通过超声能量产生钛前驱体溶液的液滴，并在连续氮气流的带动下进入炉中，使前驱体分解并结晶为二氧化钛，通过这样的过程在900℃下获得了球形黑色二氧化钛微球。与白色二氧化钛相比，合成的具有三价钛/氧空位的黑色二氧化钛微球明显表现出物理化学性质的变化。此外，合成的微球在可见光照射下对亚甲基蓝的降解表现出优异的光催化活性。这项工作提出了一种新的方法，用于简单一步合成具有氧空位的黑色金属氧化物微球，以制备具有更高效率的可见光驱动光催化剂。
