Planar and UV written channel optical waveguides prepared with siloxane–poly(oxyethylene)–zirconia organic–inorganic hybrids. Structure and optical properties

Design of new nanomaterials for their use in catalysis and photochemistry

“…2). This phenomenon is widely known for over 50 years 21 but only in recent years with the control of different synthetic approaches at the nanoscale level, they become interesting for new technologies such as photonics 22 , photocatalysis 23,24 , photovoltaics 25 , sensors 26 , biotechnology 27 , etc. The most studied UC systems are inorganic matrices doped with lanthanide ions (e.g.…”

“…26,27 Several synthetic pathways have been reported to obtain these compounds 27 In this thesis chapter a fast and environmentally friendly microwave-assisted synthesis of ZrO 2 and WO x -ZrO 2 nanoparticles is presented. The crystal phase of zirconia and the distribution of W species will be tuned through an accurate control of the synthetic conditions.…”

“…Er 3+ , Tm 3+ , Yb 3+ ). Among them, hexagonal phase of NaYF 4 is the most studied because is by far the most efficient up-converter due to a wide energy bandgap (~8eV) and its low phonon energy (~360 cm -1 ) 27 , as compared to oxide nanocrystals 28 . Even so, it presents several disadvantages such as limited thermal and chemical stability, complex synthetic pathways and the use of highly toxic and expensive fluoride reagents.…”

“…25,26 Dispersion interactions were evaluated using the D3 Grimme's method. 27 The (-111) facet of monoclinic zirconia and the (101) facet of tetragonal zirconia were represented by means of (2x2) …”

“…Thus, nanoparticles that expose preferentially (110) and (111) planes show high selectivity toward the carbamoylated product while NPs with preferentially (100) exposed facet show higher selectivity toward the methylated products. 27 Gold NPs 111 oriented has been synthesized on layered N-doped graphene. This catalyst has been tested on Ullmann-like homocoupling, C-N cross coupling and in the oxidative coupling of benzene to benzoic acid, showing six orders of magnitude enhancement compared to non-oriented gold NPs.…”