Preparation and characterization of carbon nanomaterials prepared by thermal treatment of biomass DNA

在相同条件下，采用常规水热反应器和微波反应器进行了DNA碳纳米材料（碳量子点）的水热合成，比较了产物的荧光性能。结果发现，虽然两种反应产物的发射波长相似，但在微波反应器中制备的碳量子点的荧光是在常规HT加热反应中获得的碳量子点的1.5-2倍。接下来，通过在300-500 ℃下进行热解处理和在200 ℃下进行水解处理，从DNA或DNA衍生物制备生物炭和水炭。通过标准间歇吸附实验研究了所得半焦对典型环境污染物（重金属离子和药物）的吸附性能。DNA衍生的生物炭和水炭显示出低吸附容量（约100 mg/L）。1 mg/g及以下）对所有研究的吸附剂的影响。DNA材料在热处理过程中吸附容量的下降归因于含氮和其他官能团的分解，这些官能团作为与吸附分子结合的活性中心。因此，DNA衍生炭作为吸附剂的应用受到限制。此外，得出的结论是，DNA中磷酸部分的存在阻止了研究开始时提出的石墨碳结构的形成。

The hydrothermal synthesis of DNA carbon nanomaterials (carbon dots) using a conventional hydrothermal reactor and the microwave reactor under the same conditions were conducted to compare the fluorescent properties of products. It was found that while the emission wavelengths were similar for both types of reaction products, the carbon dots prepared in the microwave reactor had 1.5-2-fold higher fluorescence compared to those obtained in the conventional HT heating reaction.Next, biochars and hydrocars were prepared from DNA or DNA-derived materials by the pyrolytic treatment at 300-500 degrees and hydrolytic treatment at 200 degrees. The obtained chars were studied for their adsorption capacities towards typical environmental pollutants (heavy metal ions and pharmaceuticals) by standard batch adsorption experiments. DNA-derived biochars and hydrochars showed low adsorption capacities (ca. 1 mg/g and below) towards all studied adsorbents compared to the original DNA and DNA containing materials and standard adsorbents such as activated carbon. The decrease in the adsorption capacity during thermal treatment of DNA materials was ascribed to the decomposition of nitrogen-containing and other functional groups that served as active centers for binding with the adsorbing molecules. The application of DNA-derived chars as adsorbents was thus shown to be limited. Furthermore, it was concluded that the presence of the phosphate moieties in the DNA prevented the formation of the graphitic carbon structures suggested in the beginning of the study.