Gd2O2SO4:Eu3+ spherical phosphor was successfully synthesized through a simple hydrothermal synthesis routine from commercially available Gd-2(SO4)(3)center dot 8H(2)O. Eu-2(SO4)3 center dot 8H(2)O and urea as the starting materials. The as-synthesized products were characterized by XRD, SEM, FT-IR, DTA-TG-DTG and photoluminescence (PL) spectra. It is found that the phase and morphologies of the precursors are strongly dependent on m value, namely, the molar ratio of urea to Gd-2(SO4)(3). The optimal m value is 2. DTA-TG-DTG, FT-IR and XRD analyses show that the optimal precursor is composed of amorphous Gd-2(OH)(2)CO3SO4 center dot H2O phase and can be converted into pure Gd2O2SO4 phase at a temperature higher than 800 degrees C for 2 h in air. SEM observation shows that the pure Gd2O2SO4 phosphor particles are spherical in shape and well dispersed, with a particle size range of about 1-3 mu m. PL spectra reveal that the strongest emission peak for Gd2O2SO4:Eu3+ spherical phosphor is located at 620 nm under 270 nm light excitation, which corresponds to the D-5(0) -> F-7(2) transition of Eu3+ ions. The quenching concentration of Eu3+ ions is 15 mol% and the concentration quenching mechanism is the exchange interaction for the D-5(0) -> F-7(2) transition of Eu3+ ions. (C) 2013 Elsevier B.V. All rights reserved.