Photocatalytic effect of TiO2-coated CaLa2(MoO4)4 and CaLa2(MoO4)4:Er/Yb nano core–shells and upconversion photoluminescence properties of CaLa2(MoO4)4:Er/Yb phosphors

• Published in: Journal of industrial and engineering chemistry (Seoul, Korea) Vol. 32; pp. 225 - 232
• Main Authors: Oh, Won-Chun, Ye, Shu, Park, Jung Gyu, Kang, Suk Hyun, Lim, Chang Sung
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 25.12.2015; 한국공업화학회
• Subjects: Kinetics; Nano core–shells; Photocatalytic effect; TiO2-coated CaLa2(MoO4)4:Er/Yb; Upconversion photoluminescence; 화학공학; Photocatalytic effect; TiO2-coated CaLa2(MoO4)4:Er/Yb; Kinetics; Nano core–shells; Upconversion photoluminescence
• ISSN: 1226-086X; 1876-794X
• DOI: 10.1016/j.jiec.2015.08.018

•TiO2-coated CaLa2(MoO4)4:Er/Yb nano core–shells were made by two-step methods.•Nano core–shells showed a fine morphology with particle sizes of 10–20nm.•10wt% TiO2-coated CaLa2(MoO4)4:Er/Yb provided the best photocatalytic effect.•UC intensities exhibited a strong 525nm and a weak 550nm emission bands.•The CIE color coordinates showed a good match with yellowish green emissions. TiO2-coated CaLa2(MoO4)4 and CaLa2(MoO4)4:Er/Yb nano core–shells were successfully synthesized using two-step procedures of the microwave sol–gel and ultrasonic methods. Well-crystallized nano core–shells showed a fine and homogeneous morphology with particle sizes of 10–20nm. The degradation efficiency for TiO2-coated CaLa2(MoO4)4 and CaLa1.7(MoO4)4:Er0.1Yb0.2 under visible light resulted in the order as 10>15>5wt%. Under excitation at 980nm, the upconversion intensities of CaLa1.7(MoO4)4:Er0.1Yb0.2 and CaLa1.5(MoO4)4:Er0.05Yb0.45 particles exhibited a strong 525nm and a weak 550nm emission bands in the green region. The CIE diagram showed a good match with yellowish green emissions.