Carbonaceous Material Modified MoO2 Nanospheres with Oxygen Vacancies for Enhanced Visible-Light Photocatalytic Oxidative Coupling of Benzylamine

Abstract

Surface oxygen vacancy (OV) plays a pivotal role in the activation of molecular oxygen and separation of electrons and holes in photocatalysis. Herein, carbonaceous materials-modified MoO2 nanospheres with abundant surface OVs (MoO2/C-OV) were successfully synthesized via glucose hydrothermal processes. In situ introduction of carbonaceous materials triggered a reconstruction of the MoO2 surface, which introduced abundant surface OVs on the MoO2/C composites. The surface oxygen vacancies on the obtained MoO2/C-OV were confirmed via electron spin resonance spectroscopy (ESR) and X-ray photoelectron spectroscopy (XPS). The surface OVs and carbonaceous materials boosted the activation of molecular oxygen to singlet oxygen (1O2) and superoxide anion radical (•O2−) in selectively photocatalytic oxidation of benzylamine to imine. The conversion of benzylamine was 10 times that of pristine MoO2 nanospheres with a high selectivity under visible light irradiation at 1 atm air pressure. These results open an avenue to modify Mo-based materials for visible light-driven photocatalysis.

Bulky olefin epoxidation under mild conditions over Mo-based oxide catalysts

“…S6D†) and in agreement with literature data. 60,70–73 The presence of Mo( iv ) sites in the Mo,M oxide nanomaterials was further supported by the fact that the very dark color of MoO 2 and MoO 2 -com was also verified for the Mo,M oxides, especially Mo(75D)M-0.3 and Mo(50D)M-24.…”