Molecular grafting is an effective technique for introducing sulfo groups into materials such as graphene oxide (GO). Existing studies on the grafting molecules with sulfo groups onto GO have been empirical, and the analytical elucidation of this process remains insufficient. In this study, we experimentally and numerically investigated the adsorption and reduction reactions between GO and two types of diaminobenzene sulfonic acids (DBSAs), namely 2,4- and 2,5-DBSAs, that possess an equal number of functional groups but different coordination numbers. Composite films of GO and DBSA were prepared from a GO/DBSA solution using centrifugation and filtration. Initially, X-ray diffractometry was employed to confirm the intercalation of DBSAs between GO layers in GO/DBSA composite films. Subsequently, X-ray photoelectron spectroscopy and Fourier-transform infrared spectroscopy were performed; the results indicated that the bonding in GO to the oxygen functional group was replaced by the bonding to the amino group of DBSA; moreover, 2,5-DBSA was more reactive towards GO than 2,4-DBSA. To further investigate the reactivity differences, density functional theory calculations were performed. The decrease in enthalpy after the reaction of 2,5-DBSA was found to be higher than that of 2,4-DBSA, suggesting higher reactivity for 2,5-DBSA.

分子接枝是将磺基引入氧化石墨烯（GO）等材料的有效技术。现有的关于将带有磺基的分子接枝到GO上的研究都是经验性的，并且对该过程的分析阐明仍然不够。在这项研究中，我们通过实验和数值研究了GO与两种二氨基苯磺酸（DBSA）（即2,4-和2,5-DBSA）之间的吸附和还原反应，这两种化合物具有相同数量的官能团但配位不同数字。通过离心和过滤从 GO/DBSA 溶液制备 GO 和 DBSA 复合膜。最初，采用 X 射线衍射法来确认 GO/DBSA 复合膜中 GO 层之间 DBSA 的插层。随后，进行了X射线光电子能谱和傅里叶变换红外光谱分析；结果表明，GO中与氧官能团的键合被与DBSA氨基的键合取代；此外，2,5-DBSA 对 GO 的反应性比 2,4-DBSA 更强。为了进一步研究反应性差异，进行了密度泛函理论计算。发现2,5-DBSA反应后的焓降低高于2,4-DBSA，表明2,5-DBSA具有更高的反应活性。