Shanghai Institute of Measurement and Testing Technology , 1500 Zhang Heng Road, Shanghai, 201203, China.
Langmuir. 2017 May 23;33(20):5015-5024. doi: 10.1021/acs.langmuir.7b00719. Epub 2017 May 8.
A 2D sandwich-like TiO-rGO composite was fabricated by the Pickering emulsion approach to improve the photocatalytic efficiency. Through an in situ growth of antase-TiO nanoparticles on the interface of O/W type GO Pickering emulsion, TiO nanoparticles were closely and densely packed on the surface of well-exfoliated rGO sheets; meanwhile, many mesoporous voids acting as the adsorption chamber and microreactor were produced. Evaluated by methylene blue (MB) degradation, its photocatalytic activity was prominent compared with the common TiO-based photocatalyst, with the rate constants 5 and 3.1 times higher under visible light and xenon lamp, respectively. When we applied it in the photocatalytic degradation of tetracycline hydrochloride (TCH, such as 10 ppm) under the visible light without adding any oxidants, the total removal efficiency was as high as 94% after 40 min. The mechanism of this good photocatalytic efficiency was illustrated by the scavenger trapping tests, which showed that this unique structure of TiO-rGO composite induced by the Pickering emulsion can significantly enhance the light absorption ability, accelerate the separation rate of electron-hole pairs, increase the adsorption capacity of organic pollutants, and hence improve the photocatalytic efficiency.
采用 Pickering 乳液法制备了二维三明治状 TiO-rGO 复合材料，以提高光催化效率。通过锐钛矿相 TiO2 纳米粒子在 O/W 型 GO Pickering 乳液界面上的原位生长，TiO2 纳米粒子紧密而密集地堆积在剥离良好的 rGO 片表面上；同时，产生了许多介孔空隙，作为吸附室和微反应器。通过亚甲基蓝 (MB) 降解评价，与常见的基于 TiO2 的光催化剂相比，其光催化活性更为突出，在可见光和氙灯下的速率常数分别提高了 5 倍和 3.1 倍。当我们在没有添加任何氧化剂的可见光下将其应用于盐酸四环素 (TCH，如 10ppm) 的光催化降解时，在 40 分钟后总去除效率高达 94%。通过清除剂捕获测试说明了这种良好的光催化效率的机制，表明这种由 Pickering 乳液诱导的 TiO-rGO 复合材料的独特结构可以显著增强光吸收能力，加速电子-空穴对的分离速率，增加有机污染物的吸附能力，从而提高光催化效率。
