[RETRACTED MANUSCRIPT] Synthesis and characterizations of manganese oxide-modified titanium dioxide photocatalyst for degradation of palm oil mill effluent

Abstract

In this research the effect of the different amount of MnO loading on commecial TiO₂ (P25) were investigated using two methods of preparation which are co-precipitation and impregnation methods. P25-MnO prepared by impregnation method showed an impressive photocatalytic performance in the degradation of Palm Oil Mill Effluent (POME) which was monitored by UV-Vis spectroscopy, compared to P25-MnO prepared by co-precipitation method. The photocatalytic activity were found maximum for 3 wt.% MnO loading on P25. The XRD of P25-MnO composites showed the presence of anatase and rutile phasees while  Fourier transform infrared spectroscopy  spectra exihibed Ti-O-Ti bond streching mode of TiO₂ appeared  below 800 cm^-1. Diffuse reflectance ultraviolet-visible spectroscopy (DR-UV Vis) of the P25-MnO composit gave maximum absorption spectra at 273 nm while fluorescence spectroscopy shown the emmision band at 421 and 469 nm when excited at 221 nm. The morphology of the best sample, P25-MnO (3wt%) synthesised using impregnation method characterized using Field Emission Scanning Electron Microscope (FESEM) exhibited various size of irregular granulated particles in the nano range size between 40 to 55 nm while energy dispersive X-Ray (EDX) spectroscopy proved the presence of Ti, Mn and O. The highest photocatalytic degrdation activity recorded was 77% performed by P25-MnO (3wt%) catalyst synthesised using impregnation method. Study show that the method of preparation of the MnO loaded P25 has an effect into producing an active catalyst for degradation of POME.