A stable 6-coordinate Fe III compound K[Fe III (THEED)] (H 4 THEED = N,N,N′,N′ -tetrakis(2-hydroxyethyl)ethylenediamine) was used as the anodic active material for all‑iron alkaline redox flow battery (ARFB), which shows a redox potential of E 1/2 = −0.93 V ( vs. Ag/AgCl). When it was paired with K 4 [Fe(CN) 6 ] as the cathodic counterpart, it gives a cell voltage of ∼1.3 V. Fe(THEED) exhibits the enhanced resistance to metallic iron deposition as compared with the 5-coordinate Fe-triethanolamine complex Fe(TEOA), mainly attributed to its saturated 6-coordinate structure with a large stabilization constant that effectively inhibits various side reactions. The cell performance of ARFB can be significantly improved by using Fe(THEED) as the negative active material. The ARFB containing 0.5 M Fe(THEED) and Fe(CN) 6 electrolytes demonstrated a discharge capacity of 14.59 Ah L −1 at a current density of 80 mA cm −2 , with a coulombic efficiency (CE) of 99.8 %, and an energy efficiency (EE) of 79.9 %. The peak power density can reach 194 mW cm −2 at a current density of 240 mA cm −2 . The system can exhibit exceptional cycling stability with 99.9 % capacity retention over 100 cycles (∼36 h). The low cost of Fe-THEED and Fe(CN) 6 components increases the economic viability, as compared to conventional V-based and previously reported Fe-based systems.
As magnetic catalyst material, great studies have been made to improve the catalytic performance of Fe 3 O 4 nanoparticles by changing the structure, but little attention has been paid to the relationship between the surface properties (the electronegativity, electron transport capacity) and the catalytic performance of Fe 3 O 4 nanoparticles. Therefore, this work was devoted to the investigation of the relationship by loading Fe 3 O 4 nanoparticles on graphene oxide(GO) grafted with N,N,N',N'-Tetrakis (2-hydroxyethy)ethylenediamine (THEED), which was denoted as TG@Fe 3 O 4 . N atoms in THEED and GO have strong electronegativity and electron mobility respectively, which greatly change the surface properties of the Fe 3 O 4 composite. A large number of characterization methods have proved that the original structure of the produced Fe 3 O 4 nanoparticles has not been changed, and the Zeta potential and cyclic voltammetry curves confirmed that the surface properties of Fe 3 O 4 composite have been improved. In the Fenton degradation experiment of MB, TG@Fe 3 O 4 can make the degradation rate of MB reach 100% in 8 min, which verified that the strong electronegativity and electron transport capacity were beneficial to the improvement of the catalytic performance of Fe 3 O 4 composite.
危险品化学品经营许可证（带存储）