Recent advances in BiOX (X = Cl, Br and I) photocatalysts: synthesis, modification, facet effects and mechanisms

Abstract

Photocatalysis technology, using semiconductor nano-materials to decompose toxic pollutants under solar light irradiation, displays great prospects for environmental protection. This review gives an overview of the applications of BiOX (X = Cl, Br and I) photocatalysts for efficient photocatalytic degradation (PCD) removal of pollutants in water/air, such as volatile organic compounds (VOCs), organic molecule pollutants, polymer pollutants and biological substances. In addition, the hybridization, facet effects and photocatalytic mechanisms of BiOX are highlighted to offer guidelines for designing highly-active BiOX visible-light-driven (VLD) photocatalysts. Furthermore, the research trends and future prospects of BiOX photocatalysts are also briefly summarized. It may lead to feasible green and efficient photocatalytic reaction systems using BiOX as the photocatalyst. Nano impactIn the area of environmental remediation, photocatalytic technology using nano-photocatalysts is one of the most important parts. In the past ten years, BiOX (X = Cl, Br and I) 2D nanosheets and 3D hierarchical structures with 2D nanoflakes have offered potential for efficient photocatalytic degradation (PCD) removal of pollutants in air, water and biological contaminants. Based on the layer structure characterized as [Bi 2 O 2 ] slabs interleaved by double slabs of halogen atoms, BiOX 2D crystals show open crystalline structures and indirect optical transitions. So, they display very high photocatalytic activity for environmental remediation. On the other hand, the thickness and exposed facets of BiOX 2D crystals also affect their photocatalytic performance and mechanism.

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.…”

Adsorption and Photodegradation of Methylene Blue by Allophane and Nanocomposite Bismuth Oxyiodide-Allophane

“…The photodegradation mechanism that occurs through two stages i.e., methylene blue adsorption by allophane followed by decomposition by BiOI. The photocatalytic mechanism of BiOI to decomposed methylene blue under direct sunlight [13] takes place by following equations:…”

Degradation of Organic Dyes over Polymeric Photocatalyst C3N3S3

“…Due to be able to use solar energy to achieve energy conversion and pollutant degradation [4,5], developing semiconductor photocatalytic materials and photocatalytic technology is expected to be an effective way to solve environmental and energy problems [6][7][8][9]. So, semiconductor photocatalytic materials and photocatalytic technology to solve energy, pollution has important practical significance [10,11]. Now, represent by TiO 2 , the semiconductor photocatalytic oxidation technology has very broad application prospects in the manufacture of new energy and protective of environmental in the field of air and water purification [12].…”