College of Natural Resources and Environment, South China Agricultural University, Guangzhou, 510642, China; Department of Chemistry, University College London, 20 Gordon St, London, WC1H 0AJ, United Kingdom.
College of Natural Resources and Environment, South China Agricultural University, Guangzhou, 510642, China.
Chemosphere. 2019 Jul;227:505-513. doi: 10.1016/j.chemosphere.2019.04.086. Epub 2019 Apr 13.
The existence of Cr(VI) and antibiotics in the environment can form the joint contaminant which can be hazardous to the ecosystem. To deal with this, we have explored a plausible method to remove the Cr(VI) and tetracycline (TC) from water by visible light photocatalysis. In this study, a series of reduced graphene oxide@ZnAlTi layered double oxides (rGO@LDO) composites with different doping ratio of rGO were successfully synthesized, which were applied in photocatalytic reduction of Cr(VI) and oxidation of TC. Graphene acts as an electron donor and it can enhance the adsorption of Cr(VI) and TC on the surface of the composites. It's found that the obtained ZnAlTi-LDO composites doped with rGO have higher photo-responsiveness in the visible region. The best-performing rGO@LDO composite (i.e., CGL3) exhibited enhanced visible light-driven photocatalytic Cr(VI) reduction, which was about five times higher than those of ZnAlTi-LDO (without adding hole catcher). The rGO@LDO also showed a satisfactory performance for photocatalytic oxidation of TC with the total organic carbon removal of 80%. However, the doping of rGO did not significantly enhance the removal of TC. The experiment of pH effects demonstrated that acidic pH was favorable to photocatalytic reduction of Cr(VI), while neutral pH was favorable to photocatalytic oxidation of TC. The band structure of ZnAlTi-LDO was first identified, and the E and E of ZnAlTi-LDO are -2.32 and 0.72 V (vs. RHE). This research provides a feasible method to remove Cr(VI) and tetracycline from water by employing ZnAlTi-LDO doped with rGO as photocatalyst.
环境中存在的六价铬（Cr(VI)）和抗生素会形成联合污染物，对生态系统构成危害。为了解决这个问题，我们探索了一种可行的方法，利用可见光光催化从水中去除六价铬（Cr(VI)）和四环素（TC）。在这项研究中，成功合成了一系列具有不同还原氧化石墨烯（rGO）掺杂比的还原氧化石墨烯@ZnAlTi 层状双氧化物（rGO@LDO）复合材料，用于光催化还原 Cr(VI)和氧化 TC。石墨烯作为电子供体，可以增强 Cr(VI)和 TC 在复合材料表面的吸附。结果表明，掺杂 rGO 的 ZnAlTi-LDO 复合材料在可见光区具有更高的光响应性。表现最佳的 rGO@LDO 复合材料（即 CGL3）表现出增强的可见光驱动光催化 Cr(VI)还原活性，是未添加空穴捕获剂的 ZnAlTi-LDO 的五倍。rGO@LDO 对 TC 的光催化氧化也表现出令人满意的性能，总有机碳去除率达到 80%。然而，rGO 的掺杂并没有显著提高 TC 的去除率。pH 值影响实验表明，酸性 pH 值有利于 Cr(VI)的光催化还原，而中性 pH 值有利于 TC 的光催化氧化。首先确定了 ZnAlTi-LDO 的能带结构，ZnAlTi-LDO 的 E 和 E 分别为-2.32 和 0.72 V（相对于 RHE）。这项研究提供了一种可行的方法，通过使用掺杂 rGO 的 ZnAlTi-LDO 作为光催化剂，从水中去除 Cr(VI)和四环素。
