Pérez-Molina Álvaro, Morales-Torres Sergio, Maldonado-Hódar Francisco J, Pastrana-Martínez Luisa M
Carbon Materials Research Group, Department of Inorganic Chemistry, Faculty of Sciences, University of Granada, Avda. Fuente Nueva, s/n ES18071 Granada, Spain.
Nanomaterials (Basel). 2020 Jun 3;10(6):1106. doi: 10.3390/nano10061106.
Functionalized graphene derivatives including graphene oxide (GO), reduced graphene oxide (rGO), and heteroatom (nitrogen/sulphur (N/S) or boron (B))-doped graphene were used to synthesize composites with TiO (T). The photocatalytic performance of composites was assessed for the degradation of Orange G dye (OG) under simulated solar light. All the prepared graphene derivatives-TiO composites showed better photocatalytic performance than bare TiO. A higher photocatalytic activity was found for the composites containing GO and N/S co-doped rGO ( = 109.2 × 10 and 48.4 × 10 min, for GO-T and rGONS-T, respectively). The influence of both initial solution pH and the reactive species involved in the OG degradation pathway were studied. The photocatalytic activity of the samples decreased with the increase of the initial pH (from 3.0 to 10.0) due to the occurrence of electrostatic repulsive forces between the photocatalysts surface and the molecules of OG, both negatively charged. The use of selective scavengers showed that although the photogenerated holes dominate the degradation mechanism, radicals and singlet oxygen also participate in the OG degradation pathway. In addition, reutilization experiments indicated that the samples were stable under the reaction conditions used.
包括氧化石墨烯（GO）、还原氧化石墨烯（rGO）以及杂原子（氮/硫（N/S）或硼（B））掺杂的石墨烯在内的功能化石墨烯衍生物被用于合成与TiO（T）的复合材料。在模拟太阳光下，评估了复合材料对橙黄G染料（OG）降解的光催化性能。所有制备的石墨烯衍生物-TiO复合材料均表现出比纯TiO更好的光催化性能。对于含有GO和N/S共掺杂rGO的复合材料（GO-T和rGONS-T的分别为109.2×10和48.4×10 min），发现具有更高的光催化活性。研究了初始溶液pH值以及OG降解途径中涉及的活性物种的影响。由于光催化剂表面与均带负电荷的OG分子之间产生静电排斥力，样品的光催化活性随初始pH值的升高（从3.0到10.0）而降低。使用选择性清除剂表明，虽然光生空穴主导降解机制，但自由基和单线态氧也参与OG的降解途径。此外，再利用实验表明样品在所使用的反应条件下是稳定的。
