Bismuth oxyhalide nanomaterials: layered structures meet photocatalysis

Abstract

In recent years, layered bismuth oxyhalide nanomaterials have received more and more interest as promising photocatalysts because their unique layered structures endow them with fascinating physicochemical properties; thus, they have great potential photocatalytic applications for environment remediation and energy harvesting. In this article, we explore the synthesis strategies and growth mechanisms of layered bismuth oxyhalide nanomaterials, and propose design principles of tailoring a layered configuration to control the nanoarchitectures for high efficient photocatalysis. Subsequently, we focus on their layered structure dependent properties, including pH-related crystal facet exposure and phase transformation, facet-dependent photoactivity and molecular oxygen activation pathways, so as to clarify the origin of the layered structure dependent photoreactivity. Furthermore, we summarize various strategies for modulating the composition and arrangement of layered structures to enhance the photoactivity of nanostructured bismuth oxyhalides via internal electric field tuning, dehalogenation effect, surface functionalization, doping, plasmon modification, and heterojunction construction, which may offer efficient guidance for the design and construction of high-performance bismuth oxyhalide-based photocatalysis systems. Finally, we highlight some crucial issues in engineering the layered-structure mediated properties of bismuth oxyhalide photocatalysts and provide tentative suggestions for future research on increasing their photocatalytic performance.

Modulation of Photocatalytic Properties by Strain in 2D BiOBr Nanosheets

“…[4][5][6][7][8][9] In BiOX, [Bi2O2] 2+ slabs are interleaved with double halogen atoms slabs by strong electrovalent bonds along the [001] direction, while two closely adjacent slabs of halogen atoms are connected by van de Waals interactions. 10,11 The dispersive VB and CB induced by sp hybridization give rise to high mobility of the photoinduced charge carriers.…”

Ag/Bi12O17Cl2 composite: A case study of visible-light-driven plasmonic photocatalyst

“…However, an excessive content of silver species acts as recombination centers for the photoinduced electron-hole pairs or cover active sites on surface to hinder the accessibility and incoming visible light, thus diminishing the photocatalytic degradation efficiency [18,19]. Thirdly, the LSPR effect of metallic Ag species excited by the absorption of visible light with specific frequency would promote the surface electron excitation and interfacial electron transfer, and thus be propitious to the enhanced photocatalytic efficiency [5,36]. Last but not the least, the suitable electronic property and morphology with enlarged specific surface areas may also contribute to the increased photocatalytic performance.…”

“…Bismuth oxychloride, a group of V-VI-VII ternary semiconductors, featured with a lamellar structure composed of [Cl-Bi-O-Bi-Cl] slices packed together with van der Waals force through chlorine atoms along the c-axis [4]. The laminated structure induces the generation of internal electric field that promotes the separation of photoproduced electron-hole pairs, thus favoring the improvement of photocatalytic performance [5]. However, the bare BiOCl is merely sensitive to UV light due to the large band gap and thus exhibits poor photocatalytic capability in visible-light region [6].…”

Synthesis, Characterization and Excellent Photocatalytic Performance of Iron-Carbon-Codoped Mesoporous Titania Nanocrystallines

“…On this background, semiconductor-based photocatalysis technique provides a "green" method for completely decomposing harmful contaminants especially some azo dyes and endocrine disrupting compounds [1,2]. Among the plentiful semiconductor materials, semiconductor TiO 2 has undoubtedly proven to be an excellent photocatalyst for the removal of aqueous pollutants.…”