Oxygen-containing surface functional groups, mesoporous structure and photothermal effect co-modulated highly-efficient H2O2 production and pollutant degradation

Abstract

Carbon-based nanomaterials are well-recognized catalysts for H2O2 production though remain insufficient for practical applications, and their photothermal effect is usually ignored. Herein, two typical carbon nanomaterials, mesoporous carbon hollow spheres (MCHS) and carbon hollow spheres (CHS), are selectively synthesized to explore the influence of oxygen-containing surface functional groups, mesoporous structure and photothermal effect on their electrocatalytic and application ability. It was found that the abundant oxygen-containing surface functional groups in MCHS can optimize the adsorption energy of *OOH while the mesoporous structure of MCHS provides plenty of electrochemical active sites, both of which significantly enhance H2O2 production selectivity of the MCHS (96.0% versus 87.0% for the CHS counterpart). Furthermore, the notable photothermal effect of the MCHS can promote the generation of more ·OH radicals and accelerate related reaction kinetics (3.5 times higher than those without NIR light irradiation) under the in-situ electro-Fenton degradation of methyl orange. As a result, remarkable degradation efficiency of 98.1% was achieved for the MCHS under the illumination of near infrared (NIR) light, outperforming those without NIR light irradiation (70.1% for MCHS and 54.7% for CHS). By integrating oxygen-containing surface functional groups, mesoporous structure and photothermal effect, this work achieves remarkable H2O2 production ability and pollutant degradation application simultaneously, providing a new avenue for the design of advanced electrocatalysts and may promote their energy related applications.