Degradation of Methylene Blue and Rhodamine B Using a New Visible Light-Responsive Photocatalyst, KSb2PO8−x N y

Abstract

Potassium phosphatoantimonates, KSb2PO8 (KSbPO) and KSb2PO8−x N y (KSbPON), are prepared by solid-state method. Urea is employed as a source of nitrogen for N-doping. Structural, morphological and optical properties of both KSbPO and KSbPON are characterized by powder X-ray diffraction (PXRD), scanning electron microscopy, energy-dispersive spectroscopy, Fourier transform infrared spectroscopy and UV–visible diffuse reflectance spectroscopy. Both samples are found to crystallize in a monoclinic lattice with Cc space group. The d-lines of KSbPO and KSbPON are refined by least square fitting the PXRD data, using POWD software to obtain their unit cell parameters. The bandgap energy (E g) of both pristine and N-doped KSbPO is found from their Kubelka–Munk plot. The KSbPON/visible photocatalytic degradation of methylene blue and rhodamine B has been investigated in aqueous heterogeneous suspension. The generation of ·OH in the presence of KSbPON during the photoreaction is verified by a fluorescence technique using terephthalic acid (TA) as a probe.