Controllable in situ synthesis of BiOBr_xI_1−x solid solution on reduced graphene oxide with enhanced visible light photocatalytic performance

Abstract

Novel composite photocatalysts, BiOBr x I 1Àx -rGO, were facilely prepared by in situ controllable deposition of BiOBr x I 1Àx solid solutions onto the surface of graphene oxide which was then reduced at mild conditions. The high-resolution transmission electron microscopy results revealed an intimate interface between BiOBr x I 1Àx and rGO in the composites. The UV-vis diffuse reflectance spectra showed that BiOBr x I 1Àx -rGO composites had intense optical absorption in the visible light region. These excellent structural and spectral properties endowed BiOBr x I 1Àx -rGO composites with enhanced photocatalytic performance.Significantly, the BiOBr 0.6 I 0.4 -rGO sample exhibited the best photocatalytic activity for the photodegradation of methyl orange under visible light irradiation (l > 420 nm). The enhanced photocatalytic activity could be attributed to more effective charge separation and transportation, and increased light absorption. The radical trapping experiments confirmed that holes and superoxide radical species were the two main reactive species in the photocatalysis process. Moreover, this material exhibited great stability and durability, which retained more than 80% degradation after several cycles. À ) with strongly oxidizing property. It has been reported that graphene (or reduced graphene oxides, rGO) based composite photocatalysts, such as graphene/BiOBr, 43 graphene/ BiOI, 44 graphene/BiOBr 0.8 I 0.2 45 and graphene/BiOCl, 46 exhibited

Unique band structure enhanced visible light photocatalytic activity of phosphorus-doped BiOI hierarchical microspheres

“…where a represents absorption coefficient, h represents Planck constant, n represents light frequency, A represents a constant, and E g represents band gap. 45 By extrapolating to the X axis (Fig. 11b), the band gap energies of BiOI and P-BiOI both were calculated to be 1.77 eV, which implies that phosphorus doping does not affect the value of the band gap.…”

“…The degradation of organic dyes may involve one or more of the active groups such as cOH, h + and cO 2 À . 18,45,52 To investigate the function of these active groups, different scavengers are added to the photocatalytic reaction system, respectively. The ethylenediaminetetraacetic acid disodium (EDTA-2Na) is used as the scavenger for h + , and the benzoquinone (BQ) is used as the scavenger for cO 2 À and the iso-propyl alcohol (IPA) is used as the scavenger for cOH (Fig.…”

Graphene Oxide/BiOCl Nanocomposite Films as Efficient Visible Light Photocatalysts

“…Recently, graphene exhibits wide applications in photocatalysis including photocatalytic water-splitting to produce hydrogen and photo-degradation for organic pollutants because of its outstanding mobility of charge carriers and much higher theoretical specific surface area (Xiang et al, 2012a , b ; Cao et al, 2014 ; Feng J. et al, 2017 ). Many studies have been focused on fabricating GO/semiconductor composites to achieve enhanced visible light photocatalytic activities (Yang et al, 2015 ). For example, Xu et al reported an efficient graphene hybridized with ZnO photocatalyst for the improved UV light photocatalytic activity (Xu et al, 2011 ).…”

Tuned Band Structure of I‐BiOBr/g‐C3N4 Heterostructure for Enhanced Photocatalytic Performance

“…Compared with pristine BiOBr, the peak position of I‐BiOBr slightly shifts to a lower angle, which preliminarily indicates that iodine ion has been successfully doped into BiOBr (Figure 1a,b). [ 29,30 ] All diffraction peaks of g‐C 3 N 4 and I‐BiOBr can be found in the as‐prepared I‐Bi/C 3 N 4 catalyst. More interestingly, the peak intensity of g‐C 3 N 4 becomes stronger when increasing the proportion content of carbon nitride from I‐Bi/C 3 N 4 ‐1 to I‐Bi/C 3 N 4 ‐4 catalyst (Figure 1a).…”