Hybrid sp<sup>3</sup>/sp<sup>2</sup> Two-Dimensional Nanodiamonds for Electrochemical Ozone Production
Xinying Yang, Wenwen Li, Shibin Wang, Huaijie Shi, Xiaosa Wang, Min Li, Lei Ding, Xing Zhong, Jianguo Wang
Abstract
Diamond electrodes have been receiving increased attention because of their favorable properties for wastewater treatment. However, the surface properties of the diamond anode have not been fully determined. Herein, an extensive study was conducted to explore hybrid two-dimension nanodiamonds (2D NDs) with variable sp 3 /sp 2 ratios as metal-free electrochemical ozone production (EOP) electrocatalysts. The 2D ND-1100 electrocatalyst with interface heterojunction of sp 3 /sp 2 exhibited outstanding EOP performance compared with the normal ND@G with sp 3 @sp 2 core–shell structure. Theoretical calculations further revealed that a high sp 3 /sp 2 ratio could effectively prohibit the O 2 */O 3 * intermediate dissociation. O 3 * with five-ring configurations exhibited lower adsorption energies than O 2 * under the high sp 3 /sp 2 ratio condition, indicating the high O 3 selectivity. The optimal sp 3 /sp 2 ratio was predicted to be 4:5 to 8:1 for O 3 selective formation. In addition, the 2D ND-1100 electrocatalyst demonstrated remarkable performance in electrodegrading organic pollutants, indicating its broad potential for efficient and advanced oxidation applications. This work provides an effective strategy for the removal of organic pollutants in wastewater based on high-performance hybrid two-dimension nanodiamonds with appropriate sp 3 /sp 2 rations.