Carbon dots (CDs) are versatile, easy to fabricate, chemically stable, and ecofriendly materials. This work presents the impact of different post-treatments, such as centrifugation and filtration, on the photoluminescence (PL) and particle-size distribution of electrochemically synthesized CDs. Because organic envelope surfactants have been reported to influence PL, bare CDs were compared with CDs modified with amphiphilic and nonamphiphilic surfactants. The CDs colloidal solution exhibited stabilization in the case of bare CDs and CDs modified by amphiphilic sodium dodecyl sulphate or the non-amphiphilic surfactant sodium citrate, as depicted by the zeta potential. The experimental results also revealed a minor influence of the organic envelope on the absorbance or PL spectrum, whereas filtration of the colloid solution had a significant impact, revealing an effect not previously observed. The change in the absorbance spectrum was attributed to sp3 hybridization due to increased disorder and surface states during the filtration process. Absorbance deconvolution also disclosed two energy substates not mentioned elsewhere. PL spectra of the filtered CD solutions revealed that the emission peaks shifted according to the incident wavelength, and the centrifuged CD synthesized with sodium citrate surfactant lacked PL due to the absence of sp3 states. This study emphasizes the importance of CD post-treatment in CD production rather than the use of surfactants.

中文翻译：

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探索用两亲性和非两亲性表面活性剂进行电化学制备的碳点后处理


碳点（CD）是一种用途广泛、易于制造、化学稳定且环保的材料。这项工作展示了不同的后处理（例如离心和过滤）对电化学合成 CD 的光致发光（PL）和粒径分布的影响。由于据报道有机包膜表面活性剂会影响 PL，因此将裸 CD 与用两亲性和非两亲性表面活性剂修饰的 CD 进行了比较。在裸 CD 和用两亲十二烷基硫酸钠或非两亲表面活性剂柠檬酸钠修饰的 CD 的情况下，CD 胶体溶液表现出稳定性，如 zeta 电位所示。实验结果还表明，有机包膜对吸光度或 PL 光谱的影响较小，而胶体溶液的过滤则具有显着影响，揭示了以前未观察到的影响。吸收光谱的变化归因于过滤过程中无序和表面状态增加导致的 sp3 杂交。吸光度解卷积还揭示了其他地方未提及的两种能量子状态。过滤后的 CD 溶液的 PL 光谱显示，发射峰根据入射波长而移动，并且用柠檬酸钠表面活性剂合成的离心 CD 由于不存在 sp3 态而缺乏 PL。这项研究强调了 CD 生产中 CD 后处理的重要性，而不是表面活性剂的使用。