A dramatic enhancement of organics degradation and electricity generation has been achieved in a wastewater fuel cell (WFC) system via strengthening superoxide radical with radical chain reaction by using a novel 3D anthraquinone/polypyrrole modified graphite felt (AQS/PPy-GF) cathode. The AQS/PPy-GF was synthesized by one-pot electrochemical polymerization method and used to in-situ generate superoxide radical by reducing oxygen under self-imposed electric field. Results showed that methyl orange (MO) were effectively degraded in AQS/PPy-GF/Fe²⁺ system with a high apparent rate constant (0.0677 min⁻¹), which was 3.9 times that (0.0174 min⁻¹) in the Pt/Fe²⁺ system and even 9.4 times that (0.0072 min⁻¹) in the traditional WFC system (without Fe²⁺). Meanwhile, it showed a superior performance for electricity generation and the maximum power density output (1.130 mW cm⁻²) was nearly 3.3 times and 5.0 times higher, respectively, when compared with the Pt/Fe²⁺ system and traditional WFC. This dramatic advance was attributed to 3D AQS/PPy-GF cathode which produces more O₂⁻ via one-electron reduction process. The presence of O₂⁻ cannot only directly contribute to MO degradation, but also promotes the final complete mineralization by turning itself to OH. Additionally, O₂⁻ accelerates the Fe²⁺/Fe³⁺ couple cycling, thus avoiding continuous addition of any external ferrous ions. Inhibition and probe studies were conducted to ascertain the role of several radicals (OH and O₂⁻) on the MO degradation. Superoxide radicals were considered as the primary reactive oxidants, and the degradation mechanism of MO was proposed. The proposed WFC system provides a more economical and efficient way for energy recovery and wastewater treatment.

中文翻译：

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通过使用新型3D AQS / PPy-GF阴极增强超氧自由基来显着增强有机物的降解和发电

通过使用新型3D蒽醌/聚吡咯改性石墨毡（AQS / PPy-GF）阴极通过自由基链反应增强超氧自由基，可以在废水燃料电池（WFC）系统中实现有机物降解和发电的显着提高。AQS / PPy-GF是通过一锅电化学聚合法合成的，用于在自加电场下通过还原氧原位生成超氧自由基。结果表明，甲基橙（MO）在AQS / PPy-GF / Fe ²⁺系统中被有效降解，具有较高的表观速率常数（0.0677 min ^-1），是Pt /中的（0.0174 min ^-1）的3.9倍。Fe ²⁺系统甚至是其的9.4倍（0.0072 min ^-1）在传统的WFC系统中（不含Fe ²⁺）。同时，其表现出优异的发电性能，与Pt / Fe ²⁺系统和传统WFC相比，最大功率密度输出（1.130 mW cm ^-2）分别高出近3.3倍和5.0倍。这一显着进步归功于3D AQS / PPy-GF阴极，该阴极可产生更多ö ₂ ^-通过单电子还原过程。存在的Ø ₂ ^-不仅可以直接促进MO退化，而且还通过转动自己OH促进最终完全矿化。此外，ö ₂ ^-加速的Fe ²⁺ / Fe的³⁺的夫妇循环，从而避免了连续添加任何外部亚铁离子。进行了抑制和探针研究，以确定几种自由基的作用（OH和 Ø ₂ ^- ）的MO降解。超氧自由基被认为是主要的反应性氧化剂，并提出了MO的降解机理。拟议中的WFC系统为能源回收和废水处理提供了一种更加经济有效的方式。