Visible-light-driven benzyl alcohol oxidation over Pt/Mn-Bi4Ti3O12 nanosheets: Structure-function relationship of multicomponent photocatalysts

Herein, a series of Pt nanoparticles modificatory Mn doped Bi4Ti3O12 ultrathin nanosheets (Pt/MnNS) are constructed as a surface functionalized photocatalyst for the visible-light-driven selective benzyl alcohol (BA) oxidation. Especially, Pt/5MnNS shows the best performance with a benzaldehyde (BD) yield rate of 1180 μmol·g−1·h−1 and a selectivity of 99.9 %. More importantly, experimental results reveal that Mn doping not only extends the optical absorption range of the photocatalyst to the visible region, but also induces the formation of more surface Ti4+δ atoms. Those Ti4+δ atoms as stronger Lewis acid centers achieve more conspicuous adsorption and activation of BA via the CO⋯Ti coordination. It makes the deprotonation of BA by photogenerated holes be easier. Meanwhile, Pt nanoparticles significantly promote the separation and transfer of the photogenerated carriers for supporting the formation of superoxide and carbon-centered radicals. Thus, the photocatalytic BA oxidation efficiency is markedly improved by surface multicomponent synergistic effect.