Here, single-atom Cu dispersed on N-doped graphene (Cu-SA/NGO) with relatively high Cu loading of 5.8 wt% was prepared for boosting the degradation of contaminants. This is the highest value yet reported for dispersion of single metal atoms on graphene. Atomically dispersed CuN₄ moieties were confirmed by high-angle annular dark field-scanning transmission electron microscopy and X-ray absorption fine structure spectroscopy. The prepared Cu-SA/NGO shows remarkable activity and stability in the degradation of various organic contaminants at neutral pH. This excellent performance is mainly ascribed to the large number of active sites obtained from high single-atom-Cu loading. Density functional theory calculations confirmed that CuN₄ moieties serve as the active sites, with low energy barriers for hydroxyl radical (˙OH) generation. These supported single-atom catalysts (SACs) catalyze the heterogeneous Fenton reaction via proton-mediated H₂O₂-homolytic pathway. This work offers a new method for fabricating various SACs with high loading levels for catalytic oxidation reactions.

中文翻译：

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N掺杂石墨烯上装饰的高负载单Cu原子在中性pH下增强Fenton样催化

在此，制备了分散在N掺杂石墨烯（Cu-SA / NGO）上的单原子Cu，其具有5.8 wt％的较高Cu负载，以促进污染物的降解。这是单金属原子在石墨烯上分散的最高值。通过高角度环形暗场扫描透射电子显微镜和X射线吸收精细结构光谱确认了原子分散的CuN ₄部分。制备的Cu-SA / NGO在中性pH下对各种有机污染物的降解表现出显着的活性和稳定性。这种优异的性能主要归因于从高单原子铜负载获得的大量活性位点。密度泛函理论计算证实了CuN ₄部分作为活性位点，对羟基自由基（radicalOH）的生成具有低能垒。这些负载的单原子催化剂（SACs）通过质子介导的H ₂ O _2均溶途径催化非均相Fenton反应。这项工作提供了一种新的方法来制备高负载水平的各种SAC，以进行催化氧化反应。