Synthesis and Photoluminescence Properties of Eu3+‐Doped Silica@Coordination Polymer Core–Shell Structures and Their Calcinated Silica@Gd2O3:Eu and Hollow Gd2O3:Eu Microsphere Products |
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Authors: | Hee Jung Lee Ju‐Un Park Sora Choi Juhee Son Moonhyun Oh |
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Affiliation: | Department of Chemistry, Yonsei University, 134 Shinchon‐dong, Seodaemun‐gu, Seoul 120‐749, Korea |
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Abstract: | The conjugation of Eu3+‐doped coordination polymers constructed from Gd3+ and isophthalic acid (H2IPA) with silica particles is investigated for the production of luminescent microspheres. A series of doping ratio‐controlled silica@coordination polymer core–shell spheres is easily synthesized by altering the amounts of metal nodes used in the reactions, where the ratios of Gd3+ and Eu3+ are 10:0 ( 1a ), 9:1 ( 1b ), 8:2 ( 1c ), 7:3 ( 1d ), 5:5 ( 1e ), and 0:10 ( 1f ). The formation of monodisperse uniform core–shell structures is achieved throughout the entirety of a series. Investigations of the photoluminescence property of the resulting series of silica@coordination polymer core–shell spheres reveal that 20% Eu3+‐doped product ( 1c ) has the strongest emission intensity. The subsequent calcination process on the silica@coordination polymer core–shell structures ( 1a ‐ f ) results in the formation of a series of doping ratio‐controlled silica@Gd2O3:Eu core–shell microspheres ( 2a ‐ f ) with uniform shell thickness. During the calcination step, the coordination polymers within silica@coordination polymer core–shells are transformed into metal oxides, resulting in silica@Gd2O3:Eu core–shell structures. The final etching process on the silica@Gd2O3:Eu core–shell microspheres ( 2a ‐ f ) produces a series of hollow Gd2O3:Eu microspheres ( 3a ‐ f ) as a result of the elimination of silica cores. The luminescence intensities of silica@Gd2O3:Eu core–shell ( 2a ‐ f ) and hollow Gd2O3:Eu microspheres ( 3a ‐ f ) also vary depending upon the doping ratio of Eu3+ ions. |
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Keywords: | coordination polymers photoluminescence hollow structures lanthanides Eu3+ dopants |
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