High mineralization efficiency and low energy consumption are the core requirements for the application of electrochemical advanced oxidation processes (EAOPs) for organic pollutants degradation. Herein we reported innovative EAOPs using natural air diffusion electrode (NADE) to improve H₂O₂ production and enhanced utilization efficiency by combination with electro-Fenton and photoelectro-Fenton (EF-PEF) for the degradation of 2,4-dichlorophenoxyacetic acid. At 0.2 and 1.2 A, the H₂O₂ production on NADE possessed 158% and 188% of that on normal aeration electrode (AE) with the total energy consumption only 7.2% and 25.4% of that on AE, respectively. Such excellent H₂O₂ production performance on NADE was attributed to ultra-high oxygen mass transfer efficiency and the feature of not requiring aeration, which reduced energy consumption greatly. A new H₂O₂ utilization efficiency (HUE) evaluation index including decomposition ratio, conversion efficiency and total utilization efficiency of H₂O₂ were proposed, demonstrating that PEF had a higher HUE than EF but not cost-effective due to a higher energy consumption. EF-PEF was thus proposed to upgrade the traditional PEF, which reduced energy consumption while maintained high mineralization efficiency. The HUE in EF-PEF process was greatly improved and superior to most reported EAOPs in literatures, which explained the high mineralization efficiency (78%-87%) with an extremely low energy consumption (0.065-0.167 kWh (g TOC)^-1) even an order of magnitude lower than that in the literatures. This work enlightened the importance of two strategies of improving both H₂O₂ production and utilization efficiency to maintain high mineralization efficiency in H₂O₂ based EAOPs.

高矿化效率和低能耗是应用电化学高级氧化工艺（EAOP）降解有机污染物的核心要求。在本文中，我们报道了创新的EAOP，它使用自然空气扩散电极（NADE）与Fenton和PhotoFenton （EF-PEF）结合使用来降解2,4-二氯苯氧基乙酸，从而提高H ₂ O _2的产生并提高利用效率。在0.2和1.2 A时，NADE上H ₂ O _2的产量分别是普通曝气电极（AE）的158％和188％，总能耗分别仅为AE的7.2％和25.4％。如此出色的H ₂ O ₂NADE的生产性能归因于超高的氧气传质效率和不需要充气的特点，从而大大降低了能耗。一种新的H ₂ O ₂利用率评估指标，包括分解率，转化效率和H ₂ O ₂总利用率提出了这些建议，表明PEF的HUE比EF高，但由于能耗较高而没有成本效益。因此，提出了EF-PEF，以对传统的PEF进行升级，从而在保持高矿化效率的同时降低了能耗。EF-PEF工艺中的HUE大大提高并优于文献中大多数报道的EAOP，这解释了高矿化效率（78％-87％）和极低的能耗（0.065-0.167 kWh（g TOC）^-1）甚至比文献中的数量级低一个数量级。这项工作启发了两种同时提高H ₂ O ₂生产和利用效率以保持H ₂ O _2中高矿化效率的策略的重要性。 基于EAOP。