Preparation and dual activation of beta-cyclodextrin derived hollow carbon spheres for highly efficient electro-Fenton

There are many reports related to the hollow carbon nanosphere with the applications in electrochemistry. However, it remains insufficient research in the field of electro-Fenton. In this study, we discovered that hollow carbon spheres can be obtained by the self-assembly of β-cyclodextrin in one step, without using any templates and toxic organic solvents. Meanwhile, activation methods were explored to create more pores and regulate the surface groups in the outer shell of the materials, which are key factors affecting the H 2 O 2 production capability. It is found that H 2 carbonization effectively converts a large number of sp 2 -C bonds on the surface of the materials to sp 3 -C, providing more active sites for reaction during the electrocatalytic process. The results show that the hollow carbon nanosphere after dual activations has the most H 2 O 2 production rate at 70 mg·L -1 ·h −1 , higher than those of carbon solid spheres and unmodified hollow carbon nanospheres. In the application of electro-Fenton, this material exhibits the degradation efficiency of 95.5 % for 50 mg·L -1 p -nitrophenol, fully meeting the needs of environmental remediation. The whole preparation and activation process is simple, environmentally friendly, easy to be scaled up and has broad application prospects. This paper enhanced the understanding of common hollow carbon spheres in the hot research field of electro-Fenton.