The ability to convert excess ammonia in water into harmless N₂ is highly desirable for environmental remediation. We present a chlorine-oxygen radical (ClO)-mediated photoelectrochemical filtration system for highly efficient and complete ammonia removal from water. The customized photochemical device comprised a Ag-functionalized TiO₂nanotube array mesh photoanode and a Pd-Cu co-modified nickel foam (Pd-Cu/NF) cathode. Under illumination, holes generated at the anode catalyzed the conversion of H₂O and Cl⁻ to HOand Cl, respectively. In turn, these radicals then reacted further, yielding ClO, which selectively decomposed ammonia. The cathode enabled further reduction of anodic byproducts such as NO₃⁻ to N₂. The complete oxidation of all dissolved ammonia was achieved within 15 min reaction under neutral conditions, where N₂ was the dominant product. The impact of key parameters was assessed, which enabled the discovery of optimal reaction conditions and the proposal of the underlying working mechanism. The flow-through configuration demonstrated a 5-fold increase of ammonia oxidation rate compared to the conventional batch reactor. The role of ClO in the oxidation of ammonia was verified with electron paramagnetic resonance and scavenger studies. This study provided greater mechanistic insights into photoelectrochemical filtration technology and demonstrated the potential of future nanotechnology for removing ammonia.

将环境中的过量氨转化为无害N _2的能力是非常需要的。我们提出了一种由氯-氧自由基（ClO）介导的光电化学过滤系统，用于高效，完全地去除水中的氨。定制的光化学装置包括一个Ag功能化的TiO ₂纳米管阵列网状光阳极和一个Pd-Cu共改性的镍泡沫（Pd-Cu / NF）阴极。在照明下，在阳极处产生的空穴催化H的转换₂ O和氯^-对HO和Cl分别。然后，这些自由基进一步反应，生成ClO，选择性分解氨。阴极阳极启用副产物如NO的进一步减少₃ ^-为N ₂。在中性条件下（其中N ₂是主要产物），在15分钟的反应时间内，所有溶解的氨都被完全氧化。评估了关键参数的影响，这使得能够发现最佳反应条件并提出了潜在的工作机制。与常规间歇式反应器相比，流通式结构证明氨氧化速率提高了5倍。ClO的作用通过电子顺磁共振和清除剂研究验证了氨氧化中的氨。这项研究为光电化学过滤技术提供了更多的机械见解，并展示了未来纳米技术去除氨的潜力。