Preparation of a novel nanocomposite NaLuF₄:Gd,Yb,Tm@SiO₂@Ag@TiO₂ with high photocatalytic activity driven by simulated solar light

Abstract

A novel nanocomposite photocatalyst NaLuF4:Gd,Yb,Tm@SiO2@Ag@TiO2 was developed for the first time. This composite material has a sandwich structure, including a NaLuF4:Gd,Yb,Tm upconversion nanocrystals (UCNCs) core, a media shell of amorphous SiO2 decorated with Ag nanoparticles, and an outer shell of anatase TiO2. The designed new structure takes advantage of the synergetic effect of UCNCs, Ag nanoparticles and TiO2. The UCNCs absorb near-infrared (NIR) light and transfer energy to TiO2, which extends the light responsive range of TiO2 to the NIR region. Ag nanoparticles not only enhance upconversion luminescence of the UCNCs but also enhance light harvesting and improve charge separation of TiO2. The results of photocatalytic applications show that the as-prepared catalyst has high photocatalytic activity. This study provides new insights into the fabrication of TiO2-based nanocomposite photocatalysts with high catalytic efficiency through effective integration of upconversion material, noble metal and TiO2 into a hetero-composite nanostructure.

Large enhanced photocatalytic activity of g-C3N4 by fabrication of a nanocomposite with introducing upconversion nanocrystal and Ag nanoparticles

“…1h ). The determined values of interplanar distances between adjacent lattice fringes are 0.50 and 0.224 nm, corresponding to (100) and (111) crystal planes of UCNPs and Ag nanoparticles, 27 respectively. The measured lattice space (0.50 nm) of UCNPs in UCNPs@SiO 2 @Ag, corresponding to the (100) hexagonal phase crystal plane of UCNPs, demonstrates that the hexagonal phase structure of UCNPs remains unchanged after forming UCNPs@SiO 2 @Ag nanoparticles.…”

“…39,60 Notably, the photocatalytic degradation activity of the as-prepared nanocomposite is also higher than the various UCNPs-modied photocatalysts reported previously (Table S1 in ESI †). 25,27,28 Considering that the amount of Ag loading may be an important factor in the photocatalysis, the dependence of the degradation efficiency of RhB on the amount of Ag loading (0-10 wt%) was studied further. As shown in Fig.…”

“…There have been reports, including ours, on the combination of UCNPs with some inorganic semiconductors such as TiO 2 and CeO 2 . 27,28 It has been proved that this strategy is effective for improving the photocatalytic activity of semiconductor photocatalysts. 25 However, there are few reports about the coupling of UCNPs with g-C 3 N 4 .…”

“…Furthermore, these inorganic semiconductors have inexible band structures, and they can hinder light absorption due to serious light scattering, but g-C 3 N 4 has a readily tunable energy band and highly transparent morphology. 27,28 Thus, a combination of g-C 3 N 4 with UCNPs is likely to make better use of the upconversion energy from NIR light and subsequently improve the photocatalytic performances of g-C 3 N 4 more efficiently.…”

Silver nanoparticles embedded hybrid organometallic complexes: Structural interactions, photo-induced energy transfer, plasmonic effect and optical thermometry

“…That results increment in fluorescence intensity directly associated with enhanced decay rates. [29][30][31] Wang et al fabricated truncated triangular silver nanoprisms and made a theoretical as well as experimental investigation about the influence of these nanoprisms on the fluorescence property of europium complex Eu(TTFA) 3 . 32 They found that the emission intensity of Eu 3+ in the complex is greatly enhanced through minimization of the nonradiative decay losses.…”