Abstract To achieve rapid separation of electron-hole pairs and improve photocatalytic degradation activity, the Fe-g-C3N4 reduced graphene hydrogel (rGH/Fe-g-C3N4) with a 3D network structure was fabricated via the hydrothermal method. Using visible light irradiation, H2O2 was added to form a photocatalysis-Fenton synergy system. The results showed that the synergistic degradation rate constant of 10% rGH/Fe-g-C3N4 was 52% higher than that of the multiphase Fenton reaction and 1.5 times higher than that of the Fe-g-C3N4. In the seventh cycle, the catalytic efficiency was still as high as 86.9%. Based on the optimized conditions from phenol degradation, the system was further applied to coking wastewater treatment, and the degradation efficiency of TOC and COD in 60 min reached 66.3% and 68.1%, respectively. Such high and stable degradation performance was ascribed to the synergy effect of photocatalysis and Fenton. Because of the photogenerated electrons not only can promote the Fe3+/Fe2+ cycle, accelerate the decomposition of H2O2, but also can quickly transfer to graphene and directly decompose H2O2 to form ·OH. Thus, a large amount of ·OH were generated through the two different channels, which greatly improve the degradation efficiency. Furthermore, rGH/Fe-g-C3N4 can be regenerated using filters without the need for additional complicated processing. This work provides an effective strategy for the deep treatment of industrial wastewater.

中文翻译：

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Fe-g-C3N4石墨烯水凝胶3D结构光催化-芬顿协同高效去除苯酚和焦化废水

摘要 为了实现电子-空穴对的快速分离并提高光催化降解活性，采用水热法制备了具有3D网络结构的Fe-g-C3N4还原石墨烯水凝胶（rGH/Fe-g-C3N4）。利用可见光照射，加入H2O2形成光催化-Fenton协同体系。结果表明，10% rGH/Fe-g-C3N4的协同降解速率常数比多相Fenton反应提高52%，比Fe-g-C3N4提高1.5倍。在第七个循环中，催化效率仍然高达86.9%。在优化苯酚降解条件的基础上，将该系统进一步应用于焦化废水处理，60 min内TOC和COD的降解率分别达到66.3%和68.1%。如此高且稳定的降解性能归功于光催化和芬顿的协同作用。由于光生电子不仅可以促进Fe3+/Fe2+循环，加速H2O2的分解，而且可以快速转移到石墨烯上，直接将H2O2分解形成·OH。因此，通过两个不同的通道产生了大量的·OH，大大提高了降解效率。此外，rGH/Fe-g-C3N4 可以使用过滤器再生，无需额外的复杂处理。这项工作为工业废水的深​​度处理提供了一种有效的策略。还能快速转移到石墨烯上，直接分解H2O2生成·OH。因此，通过两个不同的通道产生了大量的·OH，大大提高了降解效率。此外，rGH/Fe-g-C3N4 可以使用过滤器再生，无需额外的复杂处理。这项工作为工业废水的深​​度处理提供了一种有效的策略。还能快速转移到石墨烯上，直接分解H2O2生成·OH。因此，通过两个不同的通道产生了大量的·OH，大大提高了降解效率。此外，rGH/Fe-g-C3N4 可以使用过滤器再生，无需额外的复杂处理。这项工作为工业废水的深​​度处理提供了一种有效的策略。