Antenna Effect in Highly Luminescent Eu³⁺ Anchored in Hexagonal Mesoporous Silica

Abstract

A route for coordination of Eu3+ by dibenzoylmethane (DBM) covalently bonded inside hexagonal mesoporous silica was established here to produce the highly luminescent nanomaterial SiDBM−Eu(DBM)2. Thermogravimetry, luminescence, X-ray diffraction, N2 adsorption, FTIR, FTRaman, 29Si NMR, and 13C NMR in solid-state techniques were used to characterize SiDBM−Eu(DBM)2. The 29Si NMR spectrum proved that the DBM was covalently bonded to a silica framework. Thermogravimetric and titration data showed the 6.4 × 10-2 mmol of Eu3+ per gram of silica, and each Eu3+ is coordinated by three DBMs in SiDBM−Eu(DBM)2. SEM images confirmed that this material is formed by nanoaggregates with 200 nm diameter. N2 adsorption isotherms showed the SiDBM−Eu(DBM)2 complex with 800 m2 g-1 and 6.4 nm of porous diameter, characterizing mesoporosity of this nanomaterial. SiDBM−Eu(DBM)2 showed an efficient DBM to Eu3+ intramolecular energy process, namely, antenna effect, which favored a highly luminescent behavior in this modified hexagonal mesoporous silica.

Hexagonal mesoporous silica modified with copper phthalocyanine as a photocatalyst for pesticide 2,4-dichlorophenoxiacetic acid degradation

“…The template was removed from the catalyst pores by hot solvent extraction [19,20], forming an hexagonally ordered mesoporous catalyst named SiCuF 16 Pc, as shown in Scheme 1.…”

“…The organic phthalocyanine pendent group content was determined with confidence by TGA through use of residual data as reported previously [20][21][22]. The TGA curve of HMS (Fig.…”

Structural and Luminescence Properties of Silica-Based Hybrids Containing New Silylated-Diketonato Europium(III) Complex

“…Moreover, monolayer of europium complex is ascertained when monoethoxysilyldipyridine ligand is chosen as anchoring group. 25 Diketone ligands such as dibenzoylmethane 17 (DBM), acac, 17,26 or 2-thenoyltrifluoroacetone 26 (TTA) have been used respectively by Serra and Yan to synthesize polymeric molecular-based lanthanides hybrids. In the last case, the hybrid polymer reported contains disilylated TTA molecule (TTA-Si 2 , Scheme 2) obtained by reaction of 2 equiv of IPTES with 1 equiv of TTA.…”

Photocatalytic decouloration of malachite green dye by application of TiO2 nanotubes

“…This irreversibility is a consequence of capillary condensation in mesopores. Indeed, this isotherm shows that the TiO 2 nanotubes are predominantly formed by micropores with mesoporous sites forming an agglomerate structure [36][37][38]. The surface area values of catalysts were calculated by the application of BET equation in N 2 isotherms, which gave 8.0 and 76.0 m 2 g −1 for TiO 2 anatase and TiO 2 nanotubes, respectively.…”