National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Key Laboratory of Beijing for Water Quality Science and Water Environment Recovery Engineering, Beijing, 100124, China.
National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Key Laboratory of Beijing for Water Quality Science and Water Environment Recovery Engineering, Beijing, 100124, China.
Environ Res. 2024 Dec 1;262(Pt 2):119912. doi: 10.1016/j.envres.2024.119912. Epub 2024 Sep 2.
Covalent organic framework (COF) catalytic photocatalysts mediating Fenton-like reactions have been applied to the treatment of organic dyes in printing and dyeing wastewater. However, the photocatalytic performance of original COF is often unsatisfactory. This study investigated the impact of porosity modification strategies on the performance of COF photocatalysts in mediating the removal of organic dyes via Fenton-like reaction. Porosity modification was achieved by increasing the concentration of acetic acid (HAc) catalyst during COF preparation. The modified TAPB-DMTA COF (12M COF) exhibited excellent adsorption and photocatalytic properties. The Fenton-like reaction mediated by 12M COF photocatalysis removed nearly 96% of malachite green (MG) within 20 min, with a rate constant of 0.091 min, which was 2.9 and 6.5 times higher than that of g-CN and original COF under the same reaction conditions, respectively. Additionally, the modulation mechanism of porosity modification on COF photocatalysis was explored. The conduction band (CB) of COF was reduced from -0.14 eV to -0.38 eV after porosity modification, facilitating the generation of longer-lived O in the reaction system, which was conducive to efficient MG removal. Anti-interference experiments showed that the photocatalytic Fenton-like reaction system based on 12 M COF was less affected by common anions, cations and dissolved organics, while maintaining a high MG removal rate in tap water, mid-water, secondary clarifier effluent and river water. In summary, porosity modification was an effective strategy to improve the catalytic performance of original COFs. This study presented an efficient metal-free photocatalyst modification strategy for the Fenton-like reaction while avoiding the production of toxic by-products during dye degradation.
共价有机骨架（COF）催化光催化剂介导类 Fenton 反应已被应用于处理印染废水中的有机染料。然而，原始 COF 的光催化性能往往不尽人意。本研究探讨了孔隙率修饰策略对 COF 光催化剂在介导类 Fenton 反应去除有机染料性能的影响。通过在 COF 制备过程中增加乙酸（HAc）催化剂的浓度来实现孔隙率修饰。修饰后的 TAPB-DMTA COF（12M COF）表现出优异的吸附和光催化性能。通过 12M COF 光催化介导的类 Fenton 反应，孔雀石绿（MG）在 20 分钟内几乎被完全去除（去除率达到 96%），其速率常数为 0.091 min，在相同的反应条件下，比 g-CN 和原始 COF 的分别高 2.9 倍和 6.5 倍。此外，还探讨了孔隙率修饰对 COF 光催化的调制机制。COF 的导带（CB）在孔隙率修饰后从-0.14 eV 降低到-0.38 eV，从而有利于在反应体系中生成更长寿命的 O，这有利于高效去除 MG。抗干扰实验表明，基于 12M COF 的光催化类 Fenton 反应体系受常见阴离子、阳离子和溶解有机物的影响较小，同时在自来水、中水、二沉池出水和河水中保持较高的 MG 去除率。综上所述，孔隙率修饰是提高原始 COF 催化性能的有效策略。本研究提出了一种有效的无金属光催化剂修饰策略，用于类 Fenton 反应，同时避免了在染料降解过程中产生有毒副产物。
