Enhanced solar light-driven photocatalytic activity of BiOBr–ZnO heterojunctions with effective separation and transfer properties of photo-generated chargers

Abstract

The high-efficiency separation of photo-generated charges resulted in a catalyst with excellent photocatalytic activity.

Preparation, characterization and photocatalytic properties of BiOBr/ZnO composites

“…The n value is determined by the type of the transition in a semiconductor: direct band-gap semiconductor ( n = 1) or indirect band-gap semiconductor ( n = 4). As previously reported, ZnO is specified as n-type direct band-gap semiconductor and BiOBr is specified as p-type indirect band-gap semiconductor [22,23] , so for BiOBr and ZnO, the values of n are 1 and 4, respectively. The band gap energies ( E g ) of BiOBr/ZnO composites samples can be calculated from a plot of ( αh ν) 2 versus photon energy h ν, as shown in Fig.…”

“…The band gap energy values ( E g , eV) for as-synthesized samples were calculated using the function: ( αh ν) 2 = A ( h ν -E g ) n , where A , α and h ν represent constant, absorption coefficient and photon energy, respectively [22] . The n value is determined by the type of the transition in a semiconductor: direct band-gap semiconductor ( n = 1) or indirect band-gap semiconductor ( n = 4).…”

The Applications of Morphology Controlled ZnO in Catalysis

“…The photocatalytic performance increased three times compared with that of wurtzite hexagonal ZnO which was ascribed to the driving force of the inner electric field, efficiently promoting the separation and transfer of photogenerated electron-hole pairs. Similarly, Yi et al obtained novel heterojunctions of p-type BiOBr and n-type ZnO by loading amounts of BiOBr nanoflakes onto the surface of ZnO nanoflowers [219]. The decolorization rate of BiOBr-ZnO heterojunctions was found to be 3.7 and 4.7 times higher than that of pure BiOBr and ZnO, respectively.…”

Efficient charge separation of Ag2CO3/ZnO composites prepared by a facile precipitation approach and its dependence on loading content of Ag2CO3

“…To further improve the separation of photo-induced charge carriers, tremendous attempts have been executed including doping, controlling morphology, surface modifying and so on. Among all the methods developed, construction of composites is proved to be an effective method to facilitate the separation of photo-induced carriers and photocatalytic activity of ZnO [6][7][8].…”