Biomaterial Database

Adsorption and desorption mechanisms on graphene oxide nanosheets: Kinetics and tuning. 2021

Xiaodan Qu, and Qiong Hu, and Zhongqian Song, and Zhonghui Sun, and Baohua Zhang, and Jialing Zhong, and Xuyou Cao, and Yuanjin Liu, and Bolin Zhao, and Zhenbang Liu, and Yujie Shen, and Yu Bao, and Zhenxin Wang, and Yuwei Zhang, and Li Niu

Center for Advanced Analytical Science, c/o School of Chemistry and Chemical Engineering, Guangzhou University, Guangzhou 510006, China.

A knowledge of the adsorption and desorption behavior of sorbates on surface adsorptive site (SAS) is the key to optimizing the chemical reactivity of catalysts. However, direct identification of the chemical reactivity of SASs is still a challenge due to the limitations of characterization techniques. Here, we present a new pathway to determine the kinetics of adsorption/desorption on SASs of graphene oxide (GO) based on total internal reflectance fluorescence microscopy. The switching on and off of the fluorescent signal of SAS lit by carbon dots (CDs) was used to trace the adsorption process and desorption process. We find that sodium pyrophosphate (PPi) could increase the adsorption equilibrium of CDs thermodynamically and promote the substrate-assisted desorption pathway kinetically. At the single turnover level, it was disclosed that the species that can promote desorption may also be an adsorption promoter. Such discovery provides significant guidance for improving the chemical reactivity of the heterogeneous catalyst.