Carbon-Doped Bi2MoO6 Nanosheets Self-Assembled Microspheres for Photocatalytic Degradation of Organic Dyes

In this paper, carbon-doped Bi2MoO6 (C-Bi2MoO6) nanosheets self-assembled microspheres were prepared by solvothermal-calcination route to improve the photocatalytic activity of Bi2MoO6. The characterization results of XRD, FTIR, Raman, SEM, TEM, BET and XPS indicated that C replaced the O2- anion in Bi2MoO6 lattice, thinning the nanosheets, decreasing the size of microspheres, and increasing the specific surface area of Bi2MoO6. UV-Vis DRS, PL, EIS, transient photocurrent and LSV spectra demonstrated that the carbon doping reduced the band gap energy, raised the conduction band and enhanced the photogenerated electron-hole pairs separation efficiency of Bi2MoO6. Benefiting from these favorable changes, the C-Bi2MoO6 microspheres prepared at a molar ratio of C to Bi of 4 (4C-Bi2MoO6) exhibited the highest photocatalytic activity, and the photocatalytic degradation rate constant of rhodamine B by 4C-Bi2MoO6 microspheres was almost 2.26 times that by pristine Bi2MoO6 under simulated solar light. 4C-Bi2MoO6 microspheres (0.2 g/L) presented excellent photocatalytic performance toward RhB (20 mg/L) at pH value 1 and could remove 98.31% of RhB within 120 min. In addition, 4C-Bi2MoO6 microspheres also possessed a high photocatalytic activity toward methylene blue and tetracycline. 4C-Bi2MoO6 microspheres assembled from thin nanosheets can be used as effective photocatalysts to degrade toxic organic molecules from wastewater.