pH modulations of fluorescence LaVO4:Eu3+ materials with different morphologies and structures for rapidly and sensitively detecting Fe3+ ions.

With the assistance of EDTA, two fluorescence LaVO 4 :Eu 3+ materials have been synthesized via the one-step hydrothermal strategy under different pH conditions, i.e. monoclinic LaVO 4 :Eu 3+ microspheres (pH = 3) and tetragonal LaVO 4 :Eu 3+ microbundles (pH = 9). Based on series of time-dependent experiments, formation mechanisms of two products have been investigated in detail and proposed in this work. Optical characterizations conform that the luminescence property of LaVO 4 :Eu 3+ materials can be greatly affected by the structure of LaVO 4 matrixes. Meanwhile, it is found that the fluorescence property of both LaVO 4 :Eu 3+ products could be rapidly and sensitively quenched by Fe 3+ ions in water, and the quenching effect strongly depends on the concentration of Fe 3+ ions, not the crystal structure of LaVO 4 :Eu 3+ phosphors. Consequently, both the LaVO 4 :Eu 3+ products obtained in this work are considered as appropriate functional materials for sensitively and rapidly detecting the Fe 3+ ions in water. [ABSTRACT FROM AUTHOR]