Sol-gel synthesis of CaYAlO4:Tb phosphors and their application in detecting nitroaromatic compounds

Nitroaromatic compounds are highly toxic, carcinogenic, explosive, and refractory, they do great harm to human health, national security and natural ecosystem, so detecting trace amount of nitroaromatic compounds with high accuracy is crucial to the effective emission control and pollutant treatment. Herein, we synthesized CaYAlO 4 :Tb phosphors by citric acid assisted Pechini sol–gel approach. The samples were characterized by X-ray diffraction (XRD) Fourier transformation infrared (FTIR) spectroscopy, scanning electronic microscopy (SEM), laser particle analyzer, and photoluminescence (PL). The structure and morphology characterizations indicate the samples well crystallize with a K 2 NiF 4 structured CaYAlO 4 at 1100 °C and the samples show irregular morphology with smooth surface and a grain size of about 300 nm. Under irradiation of ultraviolet, CaYAlO 4 :Tb shows the characteristic emission of Tb(III), dominated by the 5 D 4 - 7 F 5 emission at 548 nm. The emission of CaYAlO 4 :Tb can be selectively quenched by nitroaromatic compounds such as p -nitrophenol, 1,2-dinitrobeneze and 4-nitrotoluene. The quenching effect (I 0 /I) can be well fitted into a linear equation, which make CaYAlO 4 :Tb an excellent candidate to detect nitroaromatic compounds. The quenching mechanism is determined to be a dynamic quenching process.