Checa M, Figueredo M, Aguinaco A, Beltrán F J
Departamento de Ingeniería Química y Química Física, Instituto Universitario de Investigación del Agua, Cambio Climático y Sostenibilidad, Universidad de Extremadura, 06006 Badajoz, Spain.
Departamento de Física de la Materia Condensada, Campus de Excelencia Internacional Global del mar, Universidad de Cádiz, 11510 Puerto Real (Cádiz), Spain.
J Hazard Mater. 2019 May 5;369:70-78. doi: 10.1016/j.jhazmat.2019.02.025. Epub 2019 Feb 10.
A graphene oxide-titania (GO/TiO) composite was synthesized via sol-gel method, and studied in aqueous Primidone mineralization with ozone and LED visible light. The photocatalyst was characterized by different techniques (XRD, TEM, SBET, TGA, UV-vis diffuse reflectance spectroscopy). The band gap value decrease from 3.14 eV for bare TiO samples to 2.5 eV in GO/TiO composites clearly shows the interaction of GO with TiO structure. Approximately 20 mg L of Primidone was removed in less than 20 min if ozone was applied, regardless of the presence or absence of light and catalyst. However, reactivity tests show a synergism effect between photocatalysis and ozonation for mineralization purposes. The combination of ozone and GO improved the activation of TiO under visible light. Process optimization led us to select a catalyst dosage of 0.25 g L, a light radiance of 359 W m and a GO loading in the catalyst around 0.75%. At these conditions, with photocatalytic ozonation, the presence of GO in the catalyst improved mineralization up to 82% in 2 h compared to 70% reached with bare TiO. Catalyst reusability shows no decrease of photocatalytic activity. Scavenger tests point to hydroxyl radicals as the main species responsible for Primidone removal.
通过溶胶 - 凝胶法合成了氧化石墨烯 - 二氧化钛（GO/TiO）复合材料，并研究了其在普米酮水溶液矿化过程中与臭氧和LED可见光的作用。采用不同技术（XRD、TEM、SBET、TGA、紫外 - 可见漫反射光谱）对光催化剂进行了表征。裸TiO样品的带隙值从3.14 eV降至GO/TiO复合材料中的2.5 eV，清楚地表明了GO与TiO结构之间的相互作用。如果施加臭氧，无论有无光照和催化剂，在不到20分钟内可去除约20 mg/L的普米酮。然而，反应性测试表明，光催化和臭氧化在矿化目的上具有协同效应。臭氧和GO的组合提高了TiO在可见光下的活性。工艺优化使我们选择了0.25 g/L的催化剂用量、359 W/m的光辐射强度以及催化剂中约0.75%的GO负载量。在这些条件下，通过光催化臭氧化，与裸TiO达到的70%相比，催化剂中GO的存在使矿化率在2小时内提高到82%。催化剂的可重复使用性表明光催化活性没有降低。清除剂测试表明羟基自由基是负责去除普米酮的主要物种。
