Double Br sources fabrication and photocatalytic property of p‐n junction BiOBr/ZnO composites for phenol removal

Abstract

P-n junction BiOBr/ZnO composites were prepared by a facile solvothermal process with double Br sources of CTAB and KBr. The samples were characterized by XRD, XPS, SEM, TEM, HRTEM, DRS, BET and PL. The BiOBr/ZnO composites exhibited much higher photocatalytic activity than single BiOBr and ZnO for the degradation of phenol under simulated sunlight irradiation. The enhanced photocatalytic activity of BiOBr/ZnO composites could be mainly ascribed to the high-efficiency separation of photogenerated electron-hole pairs through BiOBr/ZnO p-n junction. The reaction mechanism for the removal of phenol was also discussed. Hole and ·OH were the main reactive species. Moreover, the influence of disparate ratios of double Br sources to BiOBr/ZnO composites was also investigated. The results indicated that the BiOBr/ZnO composites prepared by double Br sources showed better photocatalytic activities than the sample prepared by single Br source.

Enhancing the Photocatalytic Performance of BiOClxI1−x by Introducing Surface Disorders and Bi Nanoparticles as Cocatalyst

“…Such outstanding effi ciency of the BiOX-15 nanosheets is also remarkably higher than the values of recently reported Bi-based photocatalysts (Table S1, Supporting Information), such as Bi 4 Ti 3 O 12 /BiOI, [ 13 ] BiOI/ZnSn(OH) 6 , [ 15 ] BiOI/BiPO 4 , [ 32 ] BiOI/Bi 2 O 3 , [ 33 ] and BiOBr/ZnO. [ 34 ] To further illustrate the photo catalytic reaction, pseudo-fi rst-order kinetics were fi tted from the degradation process, where the value of the rate constant value k was equal to the corresponding slope of the fi tting line as displayed in Figure 2 b. The rate constant value for BiOX-15 sample is 0.0263 min −1 , which is much higher than those of BiOX-18 (0.0206 min −1 ), BiOX-9 (0.0118 min −1 ), BiOX (0.0053 min −1 ), Bi (0.0064 min −1 ), and P25 (0.0006 min −1 ) samples, also showing the superior photocatalytic activity of the BiOX-15 sample.…”

Enhanced Photocatalytic Activity of BiOBr/ZnO Heterojunction Semiconductors Prepared by Facile Hydrothermal Method

“…It has been reported that the CB , VB of p-type BiOBr and n-type ZnO were 0.8 eV, 0.85 eV and 3.5 eV, 3.9 eV, respectively, which has been depicted in Figure 11 [11]. The type of band alignments at the semiconductor interface is attributed to type II staggered alignment [9].…”

“…The facile hydrothermal method was applied in the synthesis of BiOBr-ZnO composites. Compared with the only reported solvothermal method using CTAB as the solvent in [10], the operating procedures for the hydrothermal method were much easier and more environmentally friendly and showed a higher yield and purity [11]. To our knowledge, this is the first time in which the hydrothermal method was used to fabricate the BiOBr-ZnO heterojunction.…”

A Facile Approach for the Synthesis of Zn2SnO4/BiOBr Hybrid Nanocomposites with Improved Visible-Light Photocatalytic Performance

“…Coupling semiconductor photocatalysts with matched band energy levels has been proven to be an effective strategy for facilitating efficient photogenerated charge separation [ 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 ]. Owing to its desirable band gap (2.7 eV) and peculiar layered structure constituted by interlacing [Bi 2 O 2 ] slabs with double bromine slabs, BiOBr is emerging as a relatively efficient and stable visible-light-activated photocatalyst.…”