Structurally Engineered Two-Dimensional Layered Bismuth Oxyiodide Surfaces as a “Dip Photocatalyst” for a Photocatalytic Reaction

• Published in: Crystal growth & design Vol. 20; no. 8; pp. 4909 - 4918
• Main Authors: Prasad, Muvva D, Krishna, M. Ghanashyam, Batabyal, Sudip K
• Format: Journal Article
• Language: English
• Published: American Chemical Society 05.08.2020
• ISSN: 1528-7483; 1528-7505
• DOI: 10.1021/acs.cgd.9b01141

A simple protocol for the synthesis of two-dimensional (2D) layered bismuth oxyiodide (BiOI), at room temperature without any stabilizer, with well-defined exposed {001} facets and tunable morphologies (bowl shapes, square-sheet shape, and star shapes) was developed. The surface topographical analysis reveals layer-by-layer (LBL) stacking of ultrathin sheets of BiOI with a thickness of 1.8 nm. Transmission electron microscopy and selected area electron diffraction analysis established the exposed plane as {001}. A free-standing “dip photocatalyst” was fabricated by spin coating of bismuth oxyiodide (BiOI) and poly­(vinyl alcohol) (PVA) aqueous solution on a polystyrene (PS) sacrificial substrate. Free-standing composite film of BiOI–PVA with a thickness of several micrometers was achieved by dissolving the polystyrene films in toluene. The photocatalytic activity of the BiOI–PVA “dip photocatalyst” was examined by the degradation of rhodamine B under a low power visible light source. Significantly, this approach to the formation of the “dip photocatalyst” is convenient to evaluate its fate through multiple reuses.