Ultrasound-assisted synthesis of europium doped BPO nanoparticles; a new approach for Zn (aq) detection.

In this work, europium ion was doped into boron phosphate nanoparticles (BPO) using an ultrasonic method followed by the calcination process. The nanoparticles were characterized by various techniques such as X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), photoluminescence spectroscopy, transmission electron microscopy (TEM), and Fourier-transform infrared spectroscopy (FT-IR), Raman spectroscopy, and scanning electron microscopy (SEM). Doping of europium ion into the BPO host crystal was proved by cell volume calculation from XRD patterns, the shift in Raman spectra, and photoluminescence properties. In addition, the europium doped boron phosphate (BPE) as a fluorescence sensor for the quantification of Zn cation was studied. The obtained results showed the enhancement and shift of the photoluminescence peak from 292 to 340 nm. The sensor's selectivity toward this ion was verified in the presence of a variety of common interfering cations. Surprisingly, BPE revealed excellent selectivity and sensitivity towards Zn in the presence of Pb, Na, Fe, Al, Ca, Mg, Cu, Co, Ni, Mn, Cd, Hg, Ba and Fe cations. The fluorescence response was linearly proportional to the Znconcentration. After the addition of trace amounts of Zn ions into the aqueous solution, a significant enhancement of fluorescence emission occurred with the detection limit of 0.3 μM.