Efficient Photocatalytic Degradation of Dyes over Hierarchical BiOBr/β‐Co(OH)2/PVP Multicomponent Photocatalyst under Visible‐Light Irradiation

Abstract

AbstractA novel visible‐light driven BiOBr/β‐Co(OH)2/PVP (PVP=polyvinylpyrrolidone) hierarchical multicomponent photocatalyst assembled in nanosheets was synthesized by a simple one‐pot solvothermal synthesis. The as‐prepared photocatalyst was characterized by field‐emitting scanning electron microscopy, transmission electron microscopy, N2 adsorption–desorption analysis, FTIR spectroscopy, energy‐dispersive X‐ray spectroscopy, X‐ray powder diffraction analysis, X‐ray photoelectron spectroscopy, UV/Vis diffuse reflectance spectra, and inductively coupled plasma atomic emission spectrometry. This research shows that the formation of the p–n heterojunction would be very conducive to effectively inhibit the recombination of the photoexcited electron–hole pairs and enhance the photoactivity significantly. Owing to its narrow band‐gap energy (≈2.49 eV) and fast interfacial charge migration, this novel photocatalyst can efficiently absorb visible light and shows an improved ability for utilizing light energy. Although both β‐Co(OH)2 and BiOBr alone exhibit little photoactivity for the degradation of dyes, the BiOBr/β‐Co(OH)2/PVP hierarchical multicomponent photocatalyst exhibits unexpected, surprisingly high photoactivity and stability in degrading dyes in aqueous solution at moderate Co/Bi molar ratio and moderate PVP addition. The catalyst′s photoactivity is approximately 9.7 times of that of β‐Co(OH)2 and 3.2 times of that of BiOBr. This unusual photoactivity mainly arises from the synergetic chemical coupling effects between BiOBr, β‐Co(OH)2, and PVP. The excellent photoactivity and photostability of this hierarchical multicomponent photocatalyst make it a promising photocatalyst under visible‐light response. Beyond that, this novel photocatalyst can be reused many times without significant loss of its activity.