Constructing Oxygen Vacancies on Bi₂MoO₆ Nanosheets by Aqueous Ammonia Etching with Enhanced Photocatalytic NO Oxidation Performance

Abstract

Photocatalytic technology is deemed as an ideal strategy to deal with nitrogen oxides. Constructing oxygen vacancies (OVs) on semiconductors can greatly promote photogenerated charge separation efficiency, molecular activation, and photocatalytic activity. However, a novel method for OVs introduction under moderate conditions is still lacking. In the present work, a {001} facet exposed Bi 2 MoO 6 (BMO) nanosheet is treated in aqueous ammonia under mild conditions. In this procedure, OVs are successfully introduced into BMO via etching of the {MoO 4 } 2− layer by aqueous ammonia, and a OVs-rich BMO-OH catalyst is prepared. Photocatalytic performance tests convey that a NO removal ratio of 47% is obtained on the BMO-OH catalyst, which is about 2.2 times higher than that of pristine BMO material. The enhanced photoactivity is attributed to high reactant adsorption and ROS generation properties of BMO-OH caused by the introduced OVs. These findings provide new insights into OVs construction and photocatalytic technology.

Ce Doping Boosts the Photocatalytic Activity of Ultrathin Bi2MoO6 Nanosheets for Toluene Selective Oxidation

“…It indicates that Ce is doped into Bi 2 MoO 6 to replace Mo 6+ rather than Bi 3+ . According to the Raman spectra (Figure b), the characteristic peak of 365 cm –1 corresponds to the Mo–O–Mo bond in Bi 2 MoO 6 , while the peaks located at 796 and 844 cm –1 are designated to the Mo–O bond . The wave number corresponding to the Mo–O bond of 5-CBMOS has a slight blue shift relative to BMO.…”

“…According to the Raman spectra (Figure 2b), the characteristic peak of 365 cm −1 corresponds to the Mo−O−Mo bond in Bi 2 MoO 6 , while the peaks located at 796 and 844 cm −1 are designated to the Mo−O bond. 45 The wave number corresponding to the Mo−O bond of 5-CBMOS has a slight blue shift relative to BMO. The strength of two Mo−O bond peaks corresponds to the symmetric and asymmetric stretching vibrations of the MoO 6 octahedron, and the two stretching vibration modes are related to the motion of oxygen atoms perpendicular to each atomic layer.…”

2022 Pioneers in Energy Research: Jinhua Ye

“…Zhang and his co-workers reported a defect management strategy on SrNbO 2 N through Zn modification for promoted photocatalytic water oxidation . Wang’s group developed a novel method for the introduction of oxygen vacancies into Bi 2 MoO 6 nanosheets for the enhanced photoactivity in NO removal . Chen and Shi presented a new approach to enhance photocatalytic oxidation of tetracycline by introducing boron nitride quantum dots to BiOBr with a permanent magnet to improve the charge carrier transfer .…”

Modulation of the Internal Electric Field in Te-Doped Bi2MoO6 Nanosheets: Implication for the Photocatalytic Degradation of Rhodamine B and Photooxidation of Benzylamine

“…The hybridization between O 2p and Bi 6s states at the valence band leads to a narrowed band gap (ranging from 2.4 to 2.7 eV), enabling effective visible light absorption (Figure S1). , Additionally, the IEF within Bi 2 MoO 6 , resulting from the polarization caused by the positive and negative charges of the (Bi 2 O 2 ) 2+ and (MoO 4 ) 2– layers, respectively, facilitates the efficient separation of photogenerated charge carriers. , Extensive investigations with various forms of Bi 2 MoO 6 have been reported for many applications such as the degradation of organic molecules, water oxidation to produce O 2 gas, NO oxidation, CO 2 reduction, amines coupling reaction, Cr­(VI) reduction, and toluene and ethylbenzene oxidation. − However, the photocatalytic performance of Bi 2 MoO 6 is currently limited due to poor quantum efficiency, resulting from insufficient separation of photoexcited charge carriers and surface active sites …”