TY - JOUR A1 - Pellegrino, F. A1 - Sordello, F. A1 - Mino, L. A1 - Prozzi, M. A1 - Mansfeld, Ulrich A1 - Hodoroaba, Vasile-Dan A1 - Minero, C. T1 - Polyethylene Glycol as Shape and Size Controller for the Hydrothermal Synthesis of SrTiO3 Cubes and Polyhedra JF - Nanomaterials N2 - Understanding the correlation between the morphological and functional properties of particulate materials is crucial across all fields of physical and natural sciences. This manuscript reports on the investigation of the effect of polyethylene glycol (PEG) employed as a capping Agent in the synthesis of SrTiO3 crystals. The crucial influence of PEG on both the shape and size of the strontium titanate particles is revealed, highlighting the effect on the photocurrents measured under UV–Vis irradiation. KW - Polyethylene glycol KW - Strontium titanate KW - Controlled morphology KW - Photoelectrochemistry KW - Electron microscopy KW - EDS PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-512892 DO - https://doi.org/10.3390/nano10091892 VL - 10 IS - 9 SP - 1892 PB - MDPI CY - Basel, CH AN - OPUS4-51289 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pellegrino, F. A1 - Sordello, F. A1 - Mino, L. A1 - Minero, C. A1 - Hodoroaba, Vasile-Dan A1 - Martra, G. A1 - Maurino, V. T1 - Formic acid photoreforming for hydrogen production on shape-controlled anatase TiO2 nanoparticles: Assessment of the role of fluorides, {101}/{001} surfaces ratio, and platinization JF - ACS Catalysis N2 - Hydrogen production via formate photoreforming on TiO2 is characterized by marked dependence on the ratio between {101} and {001} surfaces for anatase nanoparticles. We observed higher rates of hydrogen Evolution with the increase of the {101} facets presence, owing to their reductive nature. This helps the Pt photodeposition in the early stages of Irradiation and, then, the hydrogen ion reduction reaction. The selective photodeposition of 2 nm Pt nanoparticles on {101} facets was confirmed by transmission electron microscopy (TEM) micrographs. The results are confirmed also by experiments carried out without the use of Pt as cocatalyst and by photoelectrochemical measurements. The work also explains the marginal effect of the fluorination on the H2 evolution. KW - Titanium dioxide KW - Fluoride KW - Platinum KW - Nanoparticles KW - Controlled-shape KW - Hydrogen photoproduction KW - Surface PY - 2019 UR - https://pubs.acs.org/doi/10.1021/acscatal.9b01861 DO - https://doi.org/10.1021/acscatal.9b01861 SN - 2155-5435 VL - 9 IS - 8 SP - 6692 EP - 6697 PB - ACS Publications AN - OPUS4-48355 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mino, L. A1 - Pellegrino, F. A1 - Rades, Steffi A1 - Radnik, Jörg A1 - Hodoroaba, Vasile-Dan A1 - Spotto, G. A1 - Maurino, V. A1 - Martra, G. T1 - Beyond shape engineering of TiO2 nanoparticles: Post-synthesis treatment dependence of surface hydration, hydroxylation, Lewis acidity and photocatalytic activity of TiO2 anatase nanoparticles with dominant {001} or {101} facets JF - ACS Applied Nano Materials N2 - TiO2 anatase nanoparticles are among the relevant players in the field of light-responsive semiconductor nanomaterials used to face environmental and energy issues. In particular, shape-engineered TiO2 anatase nanosheets with dominant {001} basal facets gained momentum because of the possibility to exploit different and/or improved functional behaviors with respect to usual bipyramidal TiO2 anatase nanoparticles, mainly exposing {101} facets. Nevertheless, such behavior depends in a significant extent on the physicochemical features of surfaces exposed by nanosheets. They can vary in dependence on the presence or removal degree of capping agents, namely, fluorides, used for shape-engineering, and experimental investigations in this respect are still a few. Here we report on the evolution of interfacial/ surface features of TiO2 anatase nanosheets with dominant {001} facets from pristine nanoparticles fluorinated both in the bulk and at their surface to nanoparticles with F− free surfaces by treatment in a basic solution and to totally F− free nanoparticles by calcination at 873 K. The nanoparticles fluorine content and its subsequent evolution is determined by complementary techniques (ion chromatography, TOF-SIMS, XPS, AES, SEM-EDX), probing different depths. In parallel, the evolution of the electronic properties and the Ti valence state is monitored by UV−vis spectroscopy and XPS. The calcination treatment results in {001} facets poorly hydroxylated, hydrated, and hydrophilic, which appear as surface features consequent to the expected (1 × 4) reconstruction. Moreover, IR spectroscopy of CO adsorbed as probe molecule indicates that the Lewis acidity of Ti4+ sites exposed on (1 × 4) reconstructed {001} facets of calcined TiO2 nanosheets is weaker than that of cationic centers on {101} facets of bipyramidal TiO2 anatase nanoparticles. The samples have also been tested in phenol photodegradation highlighting that differences in surface hydration, hydroxylation, and Lewis acidity between TiO2 nanoparticles with nanosheet (freed by F− by calcination at 873 K) and bipyramidal shape have a strong impact on the photocatalytic activity that is found to be quite limited for the nanoparticles mainly exposing (1 × 4) reconstructed {001} facets. KW - Nanoparticles KW - TiO2 KW - F- doping KW - Shape-controlled nanoparticles KW - Nanosheets PY - 2018 DO - https://doi.org/10.1021/acsanm.8b01477 SN - 2574-0970 VL - 1 IS - 9 SP - 5355 EP - 5365 PB - ACS Publications CY - Washington, DC, U.S.A. AN - OPUS4-46157 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -