Biosynthesis of lanthanum oxychloride nanoparticles as a photocatalyst

Lanthanide compound nanostructures such as oxides and hydroxides, lanthanum oxyfluoride, fluorides, and phosphates have received broad attention because of their outstanding magnetic, catalytical and optical properties arising from the 4f electron configuration of the lanthanides [1,2]. Among these materials lanthanum oxychloride (LaOCl) is of great interest because of their attractive properties and tremendous applications such as catalyst supports, luminescent materials, conversion of alkanes to alkyl chlorides, gas sensors and can be doped with rare-earth ions for special applications, such as bioimaging probes [3]. In addition, LaOCl is known for the high chemical stability, nontoxicity, the low maximum phonon cutoff energy, and ability to promote efficient phonon energy transfer (ET) to dopant ions, which are originated from the low phonon vibrational energy and high ionicity of the bond between rare earth and chlorine [4,5]. In this study, LaOCl nanoparticles of tetragonal structure were successfully synthesized by a facile sol-gel method using tragacanth gel. This method has many benefit such as nontoxic, economic viability, ease to scale up, less time consuming and environmental friendly method for the synthesis of LaOCl nanoparticles without using any organic chemicals. The sample was investigated by energy dispersive X-ray analysis (EDX), powder X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), Fourier transforms infrared spectroscopy (FTIR). In addition, the photocatalytic degradation activity of LaOCl nanoparticles were evaluated using reactive blue 21 dye as organic contaminant irradiated only with visible light from fluorescent lamp. Catalytic reactions were monitored by using UV–Vis spectrophotometer.