School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China.
School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China.
J Hazard Mater. 2020 May 5;389:122051. doi: 10.1016/j.jhazmat.2020.122051. Epub 2020 Jan 10.
Efficient activation of peroxydisulfate (PDS, SO) was achieved in this study by a hybrid of reduced graphene oxide (rGO) and layered double hydroxide (LDH). The peroxydisulfate was intercalated into the interlayers of LDH that was combined with rGO. This sample contributed to 92.4 % of phenol (PhOH) removal at 25 °C with a PDS loading amount of 0.4 mmol/g, which is better than its LDH-PDS counterpart. A high activation of PDS in rGO/LDH-PDS was also observed during the oxidation of 4-bromophenol (4-BrPhOH), 2,4-dibromophenol (2, 4-BrPhOH), 2,6-dibromophenol (2, 6-BrPhOH) and bisphenol A (BPA). As a redox reaction of PDS in LDH, this result determined that the composite of rGO/LDH caused more PDS to be activated than LDH. As the defective rGO sites activated the PDS on the surface or edges of LDH layers, the breaking of the OO bond in PDS generated SO radicals from intercalated peroxydisulfate. This result was supported by the radical scavenger experiment, electron paramagnetic resonance measurements, and the increased number of oxygen functional groups in the reacted rGO. Our work thus provided a novel strategy for PDS activation to use in environmental remediation.
本研究通过还原氧化石墨烯（rGO）和层状双氢氧化物（LDH）的混合物实现了过二硫酸盐（PDS，SO）的有效活化。过二硫酸盐被插入与 rGO 结合的 LDH 的层间。在 25°C 时，当 PDS 负载量为 0.4mmol/g 时，该样品可去除 92.4%的苯酚（PhOH），优于其 LDH-PDS 对应物。在氧化 4-溴苯酚（4-BrPhOH）、2,4-二溴苯酚（2,4-BrPhOH）、2,6-二溴苯酚（2,6-BrPhOH）和双酚 A（BPA）时，在 rGO/LDH-PDS 中也观察到 PDS 的高活化。作为 LDH 中 PDS 的氧化还原反应，这一结果表明 rGO/LDH 复合材料比 LDH 更能激活更多的 PDS。由于缺陷 rGO 位点在 LDH 层的表面或边缘上激活了 PDS，PDS 中的 OO 键断裂，从插入的过二硫酸盐中生成了 SO 自由基。自由基清除剂实验、电子顺磁共振测量和反应后的 rGO 中氧官能团数量的增加支持了这一结果。因此，我们的工作为过二硫酸盐在环境修复中的活化提供了一种新的策略。
