Constructing BiOBr/g-C3N4/Bi2O2CO3 Z-scheme photocatalyst with enhanced photocatalytic activity

Abstract

Novel camellia-structured Z-scheme BiOBr/g-C 3 N 4 /Bi 2 O 2 CO 3 was simply prepared by a hydrothermal method and photodegraded Rhodamine B under visible light within 60 min with much higher degradation e ciency (98%) contrasted with pure BiOBr, g-C 3 N 4 and Bi 2 O 2 CO 3 . Radical trapping experiments exhibited the main reactive species (•O 2 -) during degradation process. The formation of Z-scheme heterojunction improved rate of charge separation, enhanced absorption of visible light and thus promoted the photocatalytic activity. The Z-scheme heterojunction is a promising material for the removal of dye in e uents.

Fabrication of 2D/2D BiOBr/g-C3N4 with efficient photocatalytic activity and clarification of its mechanism

“…Thus, if BiOBr/g-C 3 N 4 adopts the band-band transfer, O 2 À and OH could not be formed. On the other hand, the Z-scheme mechanism 21,35,37,41 and the S-scheme mechanism 42,43 have also been reported. However, the solid experimental evidence needs to be further verified deeply and comprehensively, especially combining theoretical calculations with in situ X-ray photoelectron spectrometry (in situ XPS).…”

“…For instance, BiOBr/g-C 3 N 4 heterostructure has been widely reported for pollutant degradation due to its good photocatalytic activity and stability. 17–43 However, the separation and transfer mechanism of photoexcited electrons and holes is a controversial issue. For example, some references 17,24,31 reported that the enhanced photocatalytic activity of BiOBr/g-C 3 N 4 is attributed to the band–band transfer mechanism (the photoexcited electrons on the CB of g-C 3 N 4 are transferred into the CB of BiOBr, and the photoexcited holes on the VB of BiOBr are transferred into the VB of g-C 3 N 4 ).…”

Synthesis of double Z-scheme CdS/Bi2O2CO3/BiOCl heterojunction photocatalysts for degradation of rhodamine B under visible light

“…7b, the band gaps of CdS, BSC, and BOC were 2.20, 3.30, and 3.36 eV, respectively. The VB and CB potentials of the semiconductor were determined by eqn (2) and (3): 48 E VB = X − Ee + 0.5Eg E CB = E VB − Egwhere Ee is the free energy under the hydrogen standard, E CB is the conduction band potential, X is the electronegativity of the material, and E VB is the valence band potential. The X values of CdS, BSC, and BOC were 5.05, 6.54, and 6.33 eV, respectively.…”

“…values of CdS, BSC, and BOC were 5.05, 6.54, and 6.33 eV, respectively. 31,[47][48][49] The E VB values of CdS, BSC, and BOC were calculated to be 1.65, 3.69, and 3.51 eV, and their E CB values were calculated to be −0.55, 0.39, and 0.15 eV, respectively. Reaction Chemistry & Engineering Paper…”

Revealing the charge transfer mechanism and assessing product toxicity in the 2D/1D Bi2O2CO3/Bi8(CrO4)O11 heterostructure system

“…15,28 Bi 2 O 2 CO 3 as a typical layered structure photocatalyst has been widely investigated in wastewater purification. [29][30][31] To enhance the activity, various semiconductors have been applied to couple with Bi 2 O 2 CO 3 , such as BiOCl, [32][33][34] Bi 2 O 3 , [35][36][37] C 3 N 4 , [38][39][40] etc. Sun et al discovered that the photoactivity for degrading typical pollutants (such as rhodamine B, phenol, and bisphenol A) under visible light was significantly improved by constructing a type II scheme Bi 2 O 2 CO 3 /Bi 2 O 4 heterojunction.…”