New Fe-doped two-dimensional BiVO4 nanosheets for direct methane conversion to methyl oxygenates

Photocatalytic methane conversion is a sustainable approach to transform methane under mild conditions into its value-added derivatives for the petrochemical industry. However, obtaining high productivity and selectivity of desired products still remains a great challenge. In this work, high-efficiency Fe-doped two-dimensional BiVO4 nanosheets have been synthesized and evaluated for photocatalytic methane conversion with H2O, O-2 or H2O2 as the oxidizer. The Fe-doped and undoped samples were obtained by hydrothermal synthesis using 3-dodecylbenzenesulfonate (SDBS) as the morphology-directing agent, and examined by XRD, SEM, EDS, TEM, XPS, UV-DRS and BET characterization techniques. The replacement of some Bi3+ with Fe3+ was a successful approach to enhance the photoexcitation process and the adsorption properties of BiVO4, resulting in an improvement in the yield of methyl oxygenates. Complete selectivity of methyl oxygenates (CH3OH and CH3OOH) was achieved, and the yield reached 217.6 mu mol g(cat)(-1) h(-1) in 2 h under visible light irradiation under mild conditions over 1.0 wt% Fe-doped BiVO4 nanosheets in the presence of H2O2, outperforming most reported studies on this reaction. This work provides new insight into the choice of a suitable oxidizer for methane conversion in the BiVO4 photocatalyst system by projecting H2O2 as the relevant oxidant.