Liu Yuan, Wang Luyan, Xue Ni, Wang Pengxiang, Pei Meishan, Guo Wenjuan
School of chemistry and chemical Engineering, University of Jinan, Jinan 250022, China.
State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China.
Materials (Basel). 2020 Feb 11;13(4):824. doi: 10.3390/ma13040824.
An ultra-highly efficient Graphene Oxide/TiO/Bentonite (GO/TiO/Bent) sponge was synthesized using an in situ hydrothermal method. GO/TiO/Bent sponge with a GO mass concentration of 10% exhibited the highest treatment efficiency of methylene blue (MB), combining adsorption and photocatalytic degradation, and achieved a maximum removal efficiency of 100% within about 70 min. To further prove the ultra-high removal capacity of the sponge, the concentration of MB in water increased to ten times the original concentration. At so high a MB concentration, the removal rate was still as high as 80% in 90 min. The photocatalytic mechanism of GO/TiO/Bent sponge was discussed through XPS, PL and radicals quenching experiments. Here Bent can immobilize TiO and react with a photo-generated hole to increase the amount of hydroxyl radical; effectively enhancing the degradation of MB.GO sponge enlarges the sensitivity range of TiO to visible light by increasing the charge separation of TiO and reducing the recombination of photo-generated electron-hole pairs. Additionally, GO sponge with an interconnected porous structure provides an effective platform to immobilize TiO/bent and makes them be easily recovered. The as-prepared sponge develops a simple and cost-effective strategy to realize the ultra-highly efficient treatment of dyes in wastewater.
采用原位水热法合成了一种超高效的氧化石墨烯/二氧化钛/膨润土（GO/TiO/Bent）海绵。GO质量浓度为10%的GO/TiO/Bent海绵对亚甲基蓝（MB）表现出最高的处理效率，结合了吸附和光催化降解，在约70分钟内实现了100%的最大去除效率。为了进一步证明该海绵的超高去除能力，将水中MB的浓度提高到原来浓度的十倍。在如此高的MB浓度下，90分钟内去除率仍高达80%。通过XPS、PL和自由基猝灭实验探讨了GO/TiO/Bent海绵的光催化机理。在此，膨润土可以固定二氧化钛并与光生空穴反应以增加羟基自由基的量；有效增强MB的降解。氧化石墨烯海绵通过增加二氧化钛的电荷分离并减少光生电子-空穴对的复合，扩大了二氧化钛对可见光的敏感范围。此外，具有相互连接的多孔结构的氧化石墨烯海绵提供了一个有效的平台来固定二氧化钛/膨润土，并使它们易于回收。所制备的海绵开发了一种简单且具有成本效益的策略，以实现废水中染料的超高效处理。
