Chemical treatments of toxic cyanide (CN^–) typically involve its conversion to cyanate (OCN^–), which is less toxic. An ideal treatment should be its conversion to N₂ and CO₂. This study proposed and demonstrated an engineered photoelectrochemical (PEC) system that converts CN^– to N₂. WO₃ has been often used as a visible light active photoanode in the PEC system, but it is stable only in the acidic condition. Since cyanide is generally treated under the alkaline condition, it is necessary to develop a PEC system that is stable in the alkaline condition. To overcome this drawback, the TaON overlayer was electrodeposited on a WO₃ film, which enhanced not only the stability of the WO₃ electrode in the neutral/alkaline condition but also the interfacial charge transfer efficiency. The WO₃/TaON electrode under visible light effectively generated reactive chlorine species (RCS) from Cl^– oxidation along with concurrent production of H₂O₂ via O₂ reduction on a graphite cathode. CN^– was oxidized to OCN^–, which subsequently reacted with RCS to produce NH₃ and further to N₂ as the final product. In particular, in situ generated H₂O₂ works synergically with RCS to enhance the CN^– oxidation and the total nitrogen (TN) removal efficiency. This study demonstrated a new method that transforms CN^– to N₂ and CO₂ as final products without using any toxic chemical reagents, which is environmentally friendly.

中文翻译：

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使用TaON覆层WO ₃薄膜和可见光的耐用电极将氰化物光转化为二氮

有毒的氰化物（CN的化学处理^- ）通常涉及其转化为氰酸酯（OCN ^- ），这是毒性较低。理想的处理方法是将其转化为N ₂和CO ₂。这项研究提出并证明了一种工程化的光电化学（PEC）系统，该系统将CN ^–转化为N ₂。WO ₃经常被用作PEC系统中的可见光活性光电阳极，但它仅在酸性条件下稳定。由于氰化物通常在碱性条件下进行处理，因此有必要开发在碱性条件下稳定的PEC体系。为了克服该缺点，将TaON覆盖层电沉积在WO _3上膜，不仅增强了WO ₃电极在中性/碱性条件下的稳定性，而且还增强了界面电荷转移效率。的WO ₃有效地产生可见光下/ TAON电极活性氯物质选自Cl（RCS）^-并发生产的H配合氧化₂ ö ₂经由Ò ₂上的石墨阴极还原。CN ^–被氧化为OCN ^–，随后与RCS反应生成NH ₃，最终生成N ₂。特别是原位生成的H ₂ O ₂与RCS协同工作，以增强CN ^–氧化和总氮（TN）去除效率。这项研究证明了一种新方法，该方法无需使用任何有毒化学试剂即可将CN ^–转化为N ₂和CO ₂作为最终产品，这对环境友好。