Urine is a nitrogenous waste biomass but can be used as an appealing alternative substrate for H₂ recovery. However, urine electrolysis suffers from sluggish kinetics and requires alkaline condition. Herein, we report a novel system to decompose urine to H₂ and N₂ under neutral conditions mediated by Cl^• using oxygen-vacancy-rich Co₃O₄ nanowire (O_v-Co₃O₄) anodes and CuO nanowire cathodes. The Co²⁺/Co³⁺ cycle in Co₃O₄ activates Cl^– in urine to Cl^•, which rapidly and selectively converts urea into N₂. Thus, electron transfer is boosted for H₂ production, eliminating the kinetic limitations. The shuttle of Co²⁺ to Co³⁺ is the key step for Cl^• yield, which is accelerated due to the introduction of O_v. Electrochemical analysis shows that O_v induces positive charge on the Co center; therefore, Co²⁺ loses electrons more efficiently to form Co³⁺. H₂ production in this system reaches 716 μmol h^–1, which is 320% that of non-radical-mediated urine electrolysis. The utilization of O_v-Co₃O₄ further enhances H₂ generation, which is 490 and 210% those of noble Pt and RuO₂, respectively. Moreover, urine is effectively degraded in 90 min with the total nitrogen removal of 95.4%, and N₂ is the final product. This work provides new insights for efficient and low-cost recovery of H₂ and urine remediation.

中文翻译：

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通过在 Co3O4 纳米线阳极中引入氧空位来快速将 Co2+ 转化为 Co3+，以在尿液处理中高效回收氢气以去除氮

尿液是一种含氮废物生物质，但可用作 H ₂回收的有吸引力的替代底物。然而，尿液电解具有缓慢的动力学并且需要碱性条件。^{在此，我们报告了一种在Cl •}介导的中性条件下使用富氧空位Co ₃ O ₄纳米线(O _v -Co ₃ O ₄ ) 阳极和CuO 纳米线阴极将尿液分解为H ₂和N _{2的新系统。Co 3} O ₄中的 Co ²⁺ /Co ³⁺循环将尿液中的Cl ^-活化为 Cl ^•，其快速和选择性地将尿素转化为 N ₂。_{因此，H 2}产生的电子转移得到促进，消除了动力学限制。^{Co 2+}到Co ³⁺的穿梭是Cl ^•收率的关键步骤，由于O _v的引入而加速。电化学分析表明，O _v在Co中心产生正电荷；因此，Co ²⁺更有效地失去电子以形成Co ³⁺。该系统中的H _{2产量达到 716 μmol h} ^-1，是非自由基介导的尿液电解的 320%。O _v的利用-Co ₃ O ₄进一步提高了H ₂的产生，分别是贵金属Pt和RuO ₂的490％和210％ 。此外，尿液在90 min内被有效降解，总氮去除率为95.4%，最终产物为N _{2 。}这项工作为高效和低成本的 H ₂回收和尿液修复提供了新的见解。