Room-temperature synthesis and photocatalytic properties of lepidocrocite by monowavelength visible light irradiation

Lepidocrocite was synthesized by aerial oxidation using an FeIIEDTA solution. The synthesis was performed under irradiation from different monowavelength light emitting diode (LED) lamps at room temperature. X-ray diffraction results showed the formation of differently crystallized lepidocrocite. The indirect bandgap values of the lepidocrocite samples were about 2.34, 2.36, and 2.31 eV for red, green, and blue light, respectively. The kinetics of the photo-decolorization of crystal violet (CV) was investigated in a system composed of lepidocrocite, H2O2, and visible light. H2O2 concentration, light irradiation, and catalyst concentration were also investigated. The rate of CV decolorization was found to fit pseudo-first-order kinetics. The results show that different as-prepared lepidocrocite have different adsorption and photocatalytic characteristics. A possible mechanism was also suggested for the dye degradation.

Lepidocrocite with different indirect bandgap values was synthesized by aerial oxidation FeIIEDTA solution under different monowavelength LED lamps irradiation at room temperature. Different photocatalytic activity was found in the decolorization of crystal violet dye.Figure optionsDownload high-quality image (259 K)Download as PowerPoint slideHighlights
► Lepidocrocite was room-temperature synthesized by monowavelength LED irradiation.
► Different wavelength irradiation led to different Eg value of lepidocrocite.
► γ-FeOOH obtained by blue LED irradiation has the highest Γmax and catalytic activity.
► A mechanism was suggested for the degradation of crystal violet dye.