The synergistic role of carbon quantum dots for the improved photocatalytic performance of Bi₂MoO₆

Abstract

Novel carbon quantum dot (CQD) modified Bi2MoO6 photocatalysts were prepared via a facile hydrothermal process. The CQD modified Bi2MoO6 materials were characterized by multiple techniques. The CQDs with the average size of about 7 nm were distributed on the surface of Bi2MoO6 nanosheets. The photocatalytic activity of as-prepared CQD modified Bi2MoO6 materials was investigated sufficiently by the photodegradation of four different kinds of pollutants, such as ciprofloxacin (CIP), bisphenol A (BPA), tetracycline hydrochloride (TC), and methylene blue (MB). The improved photocatalytic activity was observed for CQD modified Bi2MoO6 samples compared with pure Bi2MoO6 under visible light irradiation. The CQD modified Bi2MoO6 photocatalysts with a CQD content of 2 wt% exhibited the optimum photocatalytic activity, which was found to increase by about 5 times than that of the pure Bi2MoO6 for the photodegradation of CIP. This improvement was attributed to the crucial role of CQDs, which acted as a photocenter for absorbing solar light, a charge separation center for suppressing charge recombination, and a catalytic center for pollutant photo-degradation. The main active species were determined to be ˙OH and O˙-(2) by the ESR technique and analyzed by calculations as well as XPS valence spectra, and a possible photocatalytic mechanism was also proposed.

In situ growing Bi2MoO6 on g-C3N4 nanosheets with enhanced photocatalytic hydrogen evolution and disinfection of bacteria under visible light irradiation

“…It can be seen that the characteristic FT-IR spectrum of CNNs is similar to CN, indicating that the g-C 3 N 4 chemical structure has not been destroyed after exfoliation. For the pure BM, the strong peak at 723 cm −1 and weak peak at 840 cm −1 can be corresponded to the asymmetric stretching mode of MoO 6 counting in vibrations of the equatorial and apical oxygen atoms, respectively [29,41]. Notably, all the obvious peaks of CNNs and BM appeared in the BM/CNNs composites.…”

The synthesis of a Bi2MoO6/Bi4V2O11heterojunction photocatalyst with enhanced visible-light-driven photocatalytic activity

“…4a) were assigned to Bi 4f 5/2 and Bi 4f 7/2 , respectively, which corresponded to Bi 3+ . 29 Then, in the Mo 3d XPS spectra (Fig. 4b) species in the BMV-55 composite photocatalyst.…”

Preparation of α-SnWO 4 hierarchical spheres by Bi 3+ -doping and their enhanced photocatalytic activity under visible light

“…Meanwhile, multi-metal oxide semiconductors are liable to exhibit more unique crystal structure and versatile properties than traditional binary oxides, and they are triggering intense research interest in the photocatalytic field [5][6][7]. For example, stannous tungstate (SnWO 4 ) with excellent intrinsic physicochemical property has a great promise in the utilization of solar energy [8][9][10][11][12][13].…”