In-situ construction of 3D nanoflower-like BiOI/Bi2SiO5 heterojunctions with enhanced photocatalytic performance for removal of decontaminants originated from a step-scheme mechanism

Novel 3D nanoflower-like BiOI/Bi2SiO5 heterojunctions were constructed in-situ by a mild solvothermal method in the existence of ionic liquid 1-butyl-3-methylimidazolium iodine ([PrMIm]I). The BiOI/Bi2SiO5 heterojunctions display flower-like nanostructure assembled by thin nanosheets. The diameter of the nanoflower is 500–800 nm, supported by transmission electron microscope (TEM). [PrMIm]I serves as a reactant and a soft template. Among all the catalysts prepared, the 3% BiOI/Bi2SiO5 heterojunction photocatalyst holds the highest photocatalytic performance toward abatement of methyl orange (MO), phenol and Cr (VI) under sunlight irradiation. Furthermore, the composites have excellent stability, proved by the cycle experiment of phenol degradation. Experimental results reveal that enhanced photocatalytic property is attributable to the larger specific surface area, effective separation of photogenerated charge pairs, and the construction of step-scheme heterojunctions. In addition, the photoinduced charge separation of BiOI/Bi2SiO5 heterojunctions obeys a step-scheme mechanism. © 2020 Elsevier B.V.