Visible-Light Photocatalytic Removal of NO in Air over BiOX (X = Cl, Br, I) Single-Crystal Nanoplates Prepared at Room Temperature

Well-crystallized layered two-dimensional bismuth oxyhalide (BiOX; X = Cl, Br, I) single-crystal nanoplates were synthesized via a facile and low-cost method at room temperature. The as-synthesized samples were analyzed by various characterization techniques. The photocatalytic activity of the samples was evaluated by the removal of NO at the indoor air level under visible-light irradiation. The band gap and thermal stability of bismuth oxyhalides decreased with increased X atomic numbers. The as-synthesized BiOBr nanoplates exhibited highest photocatalytic activity due to the favorable factors of ultrathin nanoplates, layered structures, relatively high surface area, and suitable band structure, exceeding that of BiOCl and BiOI. The present work could provide new insight into the low-temperature preparation and appropriate selection of visible-light photocatalysts for environmental application.