Silica aerogel was prepared by a sol-gel method with combination of freeze drying.The aerogel was filled with TiCl4 in autoclave and used to fabricate a hierarchical structure of TiO_(2) nanofiber shell and SiO_(2) ae...Silica aerogel was prepared by a sol-gel method with combination of freeze drying.The aerogel was filled with TiCl4 in autoclave and used to fabricate a hierarchical structure of TiO_(2) nanofiber shell and SiO_(2) aerogel core(SiO_(2)@TiO_(2)).The TiO_(2) nanofibers with a diameter of 10-15 nm were highly crystalline and mainly grew along the(101)or(001)planes,favoring charge migration along the growth axis of the fibers.The photoluminescence(PL)emission spectra show that the TiO_(2) nanofibers exhibited much lower PL intensity than P25.The free standing TiO2 nanofibers loaded with CuO had a band gap of 3.04 eV.When CuO was hierarchically loaded on the nanofiber surface and into the aerogel core(SiO_(2)/CuO@TiO_(2)/CuO),the absorption edge significantly red shifted,and the band gap was further narrowed to 2.66 eV.Meanwhile,Fe^(3+)implanted TiO_(2) nanofibers on the aerogel surface(SiO_(2)@Fe-TiO_(2))were also fabricated in the same strategy.The CuO loaded nanofibers(SiO_(2)/CuO@Fe-TiO_(2)/CuO)had a band gap of 2.62 eV.The photocatalytic reduction of CO_(2) was performed under light irradiation by a 300 W Xe-lamp for 4 h.The methanol yield over the SiO_(2)/CuO@Fe-TiO_(2)/CuO reached~2,400 μmol·gcat^(-1) in the absence of sacrificial agent.展开更多
Light conversion agents Eul-xLx（TTA）3Phen (L denotes (La3+, Gd3+, Y3+)) complexes were prepared, and the influence of doping ions on fluorescence properties was investigated by elementary analysis, FTIR and fluoresc...Light conversion agents Eul-xLx（TTA）3Phen (L denotes (La3+, Gd3+, Y3+)) complexes were prepared, and the influence of doping ions on fluorescence properties was investigated by elementary analysis, FTIR and fluorescent spectra. The results show that FTIR spectra of Eul-xLx（TTA）3Phen complex system are identical with that of EuTTA3Phen, which indicates that the complexes (Eul-xLx（TTA）3Phen) are similar in structure to （Eu （TTA）3Phen.） For the above doping elements, co-fluorescence enhancement has the following order: Gd3+>Y3+>La3+, and the optimum mole fractions of doping elements are 0.4, 0.2 and 0.5 respectively for Gd3+, Y3+, La3+. Among all the complexes, Eu0.6Gd0.4（TTA）3Phen complex has the strongest fluorescent intensity. Applying Eu0.6Gd0.4（TTA）3Phen complex to plastic and printing inks, bright red fluorescence plastic and printing inks are obtained when the content of europium reaches 0.1%（mass fraction）.展开更多
基金The authors acknowledgement the financial supports from the Key R&D Planning Project of Hainan Province(No.ZDYF2020015)the Research Lab Construction of Hainan University(No.ZY2019HN09)the National Natural Science Foundation of China(No.51761010).
文摘Silica aerogel was prepared by a sol-gel method with combination of freeze drying.The aerogel was filled with TiCl4 in autoclave and used to fabricate a hierarchical structure of TiO_(2) nanofiber shell and SiO_(2) aerogel core(SiO_(2)@TiO_(2)).The TiO_(2) nanofibers with a diameter of 10-15 nm were highly crystalline and mainly grew along the(101)or(001)planes,favoring charge migration along the growth axis of the fibers.The photoluminescence(PL)emission spectra show that the TiO_(2) nanofibers exhibited much lower PL intensity than P25.The free standing TiO2 nanofibers loaded with CuO had a band gap of 3.04 eV.When CuO was hierarchically loaded on the nanofiber surface and into the aerogel core(SiO_(2)/CuO@TiO_(2)/CuO),the absorption edge significantly red shifted,and the band gap was further narrowed to 2.66 eV.Meanwhile,Fe^(3+)implanted TiO_(2) nanofibers on the aerogel surface(SiO_(2)@Fe-TiO_(2))were also fabricated in the same strategy.The CuO loaded nanofibers(SiO_(2)/CuO@Fe-TiO_(2)/CuO)had a band gap of 2.62 eV.The photocatalytic reduction of CO_(2) was performed under light irradiation by a 300 W Xe-lamp for 4 h.The methanol yield over the SiO_(2)/CuO@Fe-TiO_(2)/CuO reached~2,400 μmol·gcat^(-1) in the absence of sacrificial agent.
文摘Light conversion agents Eul-xLx（TTA）3Phen (L denotes (La3+, Gd3+, Y3+)) complexes were prepared, and the influence of doping ions on fluorescence properties was investigated by elementary analysis, FTIR and fluorescent spectra. The results show that FTIR spectra of Eul-xLx（TTA）3Phen complex system are identical with that of EuTTA3Phen, which indicates that the complexes (Eul-xLx（TTA）3Phen) are similar in structure to （Eu （TTA）3Phen.） For the above doping elements, co-fluorescence enhancement has the following order: Gd3+>Y3+>La3+, and the optimum mole fractions of doping elements are 0.4, 0.2 and 0.5 respectively for Gd3+, Y3+, La3+. Among all the complexes, Eu0.6Gd0.4（TTA）3Phen complex has the strongest fluorescent intensity. Applying Eu0.6Gd0.4（TTA）3Phen complex to plastic and printing inks, bright red fluorescence plastic and printing inks are obtained when the content of europium reaches 0.1%（mass fraction）.
