Enhanced photocatalytic benzyl alcohol oxidation over BiTiO ultrathin nanosheets.

Ultrathin BiTiO nanosheets (NS) with the thickness about 3.9 nm were successfully synthesized by a hydrothermal method and were used as a photocatalyst for the oxidation of benzyl alcohol (BA) to benzaldehyde (BAD). The photocatalytic performance of NS is about 8 times higher than that of bulk BiTiO. In-situ FTIR of pyridine adsorption and NH-TPD reveal that NS has more surface Lewis acid sites (Ti) for the adsorption and activation of BA. The photogenerated electrons (e) and holes (h) of NS can be fully used to produce the superoxide radicals and carbon-centered radicals, respectively. The monolayer nanosheet structure of NS not only greatly promotes the separation of photogenerated carriers, but also achieves the efficient activation of BA molecules via the CO⋯Ti coordination. This work successfully reveals the surface/interface interactions between the surface active sites of a photocatalyst and the reactive molecules via using ultrathin nanosheet as a molecular platform.