The electrocatalytic nitrate reduction reaction (NO₃RR) represents a feasible approach for the removal of harmful contaminants and the synthesis of green ammonia (NH₃). However, a significant challenge associated with NO₃RR is its sluggish kinetics. In this study, we constructed an iridium-incorporated cobalt hydroxide electrode deposited on titanium meshes (Ir@Co(OH)₂/TM), which exhibits an impressive Faraday efficiency (FE) of 91.6 ± 2.2% at −0.2 V versus the reversible hydrogen electrode, as well as the highest NH₃ yield of 927.3 ± 19.6 μmol h⁻¹ cm⁻² at −0.5 V. Furthermore, Ir@Co(OH)₂/TM maintains exceptional activity in simulated wastewater, achieving a notable NH₃ yield of 901.0 ± 71.6 μmol h⁻¹ cm⁻² with an FE of 92.7 ± 6.3% at −0.5 V. The electrode also demonstrates satisfactory performance in both alkaline media with varying NO₃⁻/OH⁻ concentrations and neutral media, indicating its broad applicability. Additionally, the minor fluctuations in current densities, NH₃ yields, and FEs observed during the 12 hours stability test and the 20-cycle test confirm the outstanding stability and durability of Ir@Co(OH)₂/TM. Notably, Ir@Co(OH)₂/TM can also facilitate the electroreduction of nitrobenzene (Ph-NO₂) to aniline (Ph-NH₂), achieving a remarkable Ph-NO₂ conversion of 90.6% and a Ph-NH₂ selectivity of 71.6% at −0.5 V. This study presents a viable method for the efficient fabrication of bifunctional electrocatalysts aimed at enhancing the production of high-value chemicals from environmental contaminants.

中文翻译：

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掺入铱的氢氧化钴电沉积在钛网上，能够将硝酸盐和硝基苯电还原成氨和苯胺


电催化硝酸盐还原反应 （NO₃RR） 代表了去除有害污染物和合成绿氨 （NH₃） 的可行方法。然而，与 NO₃RR 相关的一个重大挑战是其动力学缓慢。在这项研究中，我们构建了一个沉积在钛网 （Ir@Co（OH）₂/TM） 上的铱掺氢钴电极，与可逆氢电极相比，它在 -0.2 V 时表现出令人印象深刻的 91.6 ± 2.2% 的法拉第效率 （FE），以及最高的 NH₃ 产率，为 927.3 ± 19.6 μmol ^{h-1 cm-2}在 -0.5 V 下。此外，Ir@Co（OH）₂/TM 在模拟废水中保持了出色的活性，在 -0.5 V 下实现了 901.0 ± 71.6 μmol ^{h-1 cm-2} 的显着 NH 产率和 92.7 ± 6.3% 的 FE。该电极在具有不同 NO₃⁻/OH⁻ 浓度的碱性介质和中性介质中也表现出令人满意的性能，表明其广泛的适用性。此外，在 12 小时稳定性测试和 20 次循环测试中观察到的电流密度、NH₃ 产率和 FE 的微小波动证实了 Ir@Co（OH）₂/TM 出色的稳定性和耐用性。值得注意的是，Ir@Co（OH）₂/TM 还可以促进硝基苯 （Ph-NO₂） 电还原为苯胺 （Ph-NH₂），实现 90 的显着 Ph-NO₂ 转化率。6%，在 −0.5 V 时 Ph-NH₂ 选择性为 71.6%。本研究提出了一种高效制备双功能电催化剂的可行方法，旨在提高从环境污染物中生产高价值化学品的能力。