Synthesis of Bi₄O₅Br₂from reorganization of BiOBr and its excellent visible light photocatalytic activity

Abstract

In this study, a novel visible-light-driven Bi4O5Br2 photocatalyst was successfully synthesized via the structure reorganization of BiOBr at room temperature using NH3·H2O as a structure-controlling agent. The obtained Bi4O5Br2 exhibited outstanding visible light activity and stability compared to BiOBr and P25 for the degradation of resorcinol. The physicochemical properties of Bi4O5Br2 were analyzed and calculated by modern characterization techniques and density functional theory (DFT). The results revealed that the excellent performance could be mainly attributed to the effect of O-richness on the electronic properties of Bi and Br atoms, unique morphology, high visible-light absorption capacity, and prominent oxidation ability of photo-induced holes. Radical trapping experiments demonstrated that h(+) and ˙OH radicals were the dominant active species. Moreover, a structure reorganization mechanism was proposed, revealing that ammonia and the water-steeping process both played important roles in the fabrication of Bi4O5Br2. We believe that this facile method could be extended to fabricate other three component Bi-O-Br nanostructure systems and help elucidate the relationship between BiOBr and BixOyBrz.

LignoPhot: Photoactive Hybrid lignin/Bi4O5Br2/BiOBr Composite for Complex Pollutants Removal

“…The presence of Bi4O5Br2 is manifested by the doublet at 158.4 eV (4f7/2) and 163.8 eV (4f5/2), whereas BiOBr shows the photoemission at 159.6 eV (4f7/2) and 164.9 eV (4f5/2). 34,35 On the other hand, the formation of Bi 5+ species was not observed as was the case with the previously developed hybrid cellulose-bismuth oxybromide membrane. 18 The fragment of hydrolysis lignin particle with the grown Bi4O5Br2/BiOBr phase is shown on SEM micrograph (Figure 2B) and EDX elements distribution maps (Figure S1).…”

Facile synthesis of Bi12O17Br2 and Bi4O5Br2 nanosheets: In situ DRIFTS investigation of photocatalytic NO oxidation conversion pathway

“…Hence, Bi12O17Br2 was apparently obtained through reorganization of Bi4O5Br2. The chemical formation mechanism of Bi4O5Br2 and Bi12O17Br2 crystals was as follows: (1)-(4) [19][20][21][22][23].…”

Intensive photocatalytic activity enhancement of Bi 5 O 7 I via coupling with band structure and content adjustable BiOBr x I 1− x

“…In recent years, various laminar bismuth oxyhalide substances have been found and gradually developed to be a huge species widely applied in photocatalysis field. Except for the most simple BiOX (X = Cl, Br, I) system [8][9][10][11][12], much more attention has been paid to the complicated Bi a O b X c (X = Cl, Br, I) system, such as Bi 3 O 4 X (X = Cl, Br) [13][14][15], Bi 12 O 17 X 2 (X = Cl, Br) [16][17][18][19], Bi 4 O 5 X 2 (X = Cl, Br, I) [20][21][22][23][24], Bi 24 O 31 Br 10 [25][26][27][28][29] and Bi 5 O 7 I [30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46][47]. Although many of them have broad visible light absorption range and possess good photocatalytic activity, however, the weak photocharges separation efficiency of pure Bi a O b X c (X = Cl, Br, I) is still obvious and must be overcome.…”