Abstract:
For the efficient degradation of organic pollutants with the goal of reducing the water environment pollution, we employed an alkaline hydrothermal treatment on primeval g-C3N4 to synthesize a hydroxyl-grafted g-C3N4 (CN-0.5) material, from which we engineered a novel Fenton-like catalyst, known as Cu-CN-0.5. The introduction of numerous hydroxyl functional groups allowed the CN-0.5 substrate to stably fix active copper oxide particles through surface complexation, resulting in a low Cu leaching rate during a Cu-CN-0.5 Fenton-like process. A sequence of characterization techniques and theoretical calculations uncovered that interfacial complexation induced charge redistribution on the Cu-CN-0.5 surface. Specifically, some of the π electrons in the tris-s-triazine units were transferred to the copper oxide particles along the newly formed chemical bonds (C(π)-O-Cu), forming a π-deficient area on the tris-s-triazine plane near the complexation site. In a typical Cu-CN-0.5 Fenton-like process, a stable π-π interaction was established due to the favorable positive-negative match of electrostatic potential between the aromatic pollutants and π-deficient areas, leading to a significant improvement in Cu-CN-0.5\'s adsorption capacity for aromatic pollutants. Furthermore, pollutants also delivered electrons to the Cu-CN-0.5 Fenton-like system via a \"through-space\" approach, which suppressed the futile oxidation of H2O2 in reducing the high-valent Cu2+ and significantly improved the generation efficiency of •OH with high oxidative capacity. As expected, Cu-CN-0.5 not only exhibited an efficient Fenton degradation for several typical aromatic organic pollutants, but also demonstrated both a low metal leaching rate (0.12 mg/L) and a H2O2 utilization rate exceeding 80%. The distinctive Fenton degradation mechanism substantiated the potential of the as-prepared material for effective wastewater treatment applications.
摘要:
以减少水环境污染为目标的有机污染物的高效降解,我们对原始g-C3N4进行碱性水热处理,合成了羟基接枝的g-C3N4(CN-0.5)材料,我们从中设计了一种新型的类似芬顿的催化剂,称为Cu-CN-0.5。许多羟基官能团的引入使CN-0.5基材通过表面络合稳定地固定活性氧化铜颗粒,在类似Cu-CN-0.5Fenton的过程中,导致Cu浸出率低。一系列表征技术和理论计算揭示了界面络合在Cu-CN-0.5表面上引起电荷重新分布。具体来说,三嗪单元中的一些π电子沿着新形成的化学键(C(π)-O-Cu)转移到氧化铜颗粒中,在络合位点附近的三三嗪平面上形成π缺陷区。在典型的Cu-CN-0.5类Fenton工艺中,由于芳香污染物和缺π区域之间的静电势有利的正负匹配,建立了稳定的π-π相互作用,导致Cu-CN-0.5对芳香污染物的吸附能力显著提高。此外,污染物还通过“通过空间”方法将电子输送到Cu-CN-0.5Fenton类系统,抑制了H2O2在还原高价Cu2+中的无用氧化,并显着提高了具有高氧化能力的·OH的生成效率。不出所料,Cu-CN-0.5不仅对几种典型的芳香族有机污染物表现出有效的Fenton降解,但也表现出低金属浸出率(0.12mg/L)和H2O2利用率超过80%。独特的Fenton降解机制证实了所制备材料用于有效废水处理应用的潜力。