Biotemplate preparation of Bi2O3 nanosheet for enhanced photodegradation of methylene blue

Bi2O3 nanosheet was synthesised using China rose petal as a biotemplate for the photodegradation of methylene blue under xenon lamp irradiation. The samples were characterised by thermogravimetric analysis–differential scanning calorimetric analysis, Fourier-transform infrared spectroscopy, nitrogen adsorption, X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and ultraviolet–visible diffuse reflectance spectroscopy. The results revealed that the Bi2O3 nanosheet with pure monoclinic phase was successfully synthesised by replication of the petal template with a thickness of about 100 nm, and showed the absorption thresholds wavelength of 480 nm. Moreover, the Bi2O3 nanosheet exhibited 94.84% degradation efficiency of photodegradation of methylene blue in 180 min, which was much more active than that of the commercial α-Bi2O3 due to its high specific surface area of 45.7 m2 g−1 and wide band gap of 3.10 eV.