1.

Nanostructured N-doped TiO2 marigold flowers for an efficient solar hydrogen production from H2S

Nitrogen­doped TiO2 nanostructures in the form of marigold flowers have been synthesized for the first time using a facile solvothermal method. The structural analysis has shown that such an N­-doped TiO2 system crystallizes in the anatase structure. The optical absorption spectra have clearly shown the shift in the absorption edge towards the visible­light range, which indicates successful nitrogen doping. Microscopy studies have shown the thin nanosheets (petals) of N:TiO2 with a thickness of 2–3 nm, assembled in the form of the marigold flower with a high surface area (224 m2/g). The N:TiO2 nanostructure with marigold flowers is an efficient photocatalyst for the decomposition of H2S and production of hydrogen under solar light. The maximum hydrogen evolution obtained is higher than other known N:TiO2

COBISS.SI-ID: 2917883

2.

Excitation spectra of transition-metal atoms on the Ag (100) surface controlled by hund's exchange

In our work we investigated the series of isolated Mn, Fe, Co, and Ni adatoms on the Ag (100) surface and explain their excitation spectra. To explain the measured valence band spectra, we performed first principles calculations and we used the theoretical results to understand how the Hund’s exchange controls the physics of 3d adatoms on the surfaces of Ag (100).

COBISS.SI-ID: 2741755

3.

Photoelectrochemical properties of cadmium chalcogenide-sensitized textured porous zinc oxide plate electrodes

We report the photoelectrochemical performance of textured porous ZnO and CdX­coated ZnO films (X = S, Se).To increase the light­harvesting efficiency, we sensitized these ZnO electrodes with CdS and CdSe quantum dots, using the SILAR method. Quantum efficiency values as high as 90% were achieved with the textured porous ZnO films. These results demonstrate that both CdS and CdSe­sensitized textured porous ZnO electrodes could be potentially useful materials in light­ harvesting applications.

COBISS.SI-ID: 2740219

4.

Surface functionalization of nanostructured Fe2O3 polymorphs

Nanostructured iron(III) oxide deposits are grown by chemical vapor deposition (CVD) at 400−500 °C on Si(100) substrates from Fe(hfa) 2TMEDA (hfa = 1,1,1,5,5,5hexafluoro2,4pentanedionate; TMEDA = N,N,N′,N′tetramethylethylenediamine), yielding the selective formation of αFe2O3 or the scarcely studied εFe2O3 polymorphs under suitably optimized preparative conditions. By using Ti(OPri)4 (OPri = isopropoxy) and water as atomic layer deposition (ALD) precursors, we subsequently functionalized the obtained materials at moderate temperatures ((300 °C) by an ultrathin titanomagnetite (Fe3−xTixO4) overlayer. An extensive multitechnique characterization, aimed at elucidating the system structure, morphology, composition and optical properties, evidenced that the photoactivated hydrophilic and photocatalytic behavior of the synthesized materials is dependent both on iron oxide phase composition and ALD surface modification. The proposed CVD/ALD hybrid synthetic approach candidates itself as a powerful tool for a variety of applications where semiconductor-based nanoarchitectures can benefit from the coupling with an ad hoc surface layer.

COBISS.SI-ID: 2875387

5.

Phase relations and optoelectronic characteristics in the NdVO4-BiVO4 system

The studies using x-ray absorption spectroscopy and fluorescence spectroscopy have shown that the monoclinic BiVO4 does not allow any doping on Bi site, therefore, no modification of the bandgap is possible. However, doping of NdVO4 with Bi has been successfully reduced the NdVO4 bandgap and contributed to an increase in optical absorption.

COBISS.SI-ID: 21319654