Mesoporous Titania Powders: The Role of Precursors, Ligand Addition and Calcination Rate on Their Morphology, Crystalline Structure and Photocatalytic Activity.
We evaluate the influence of the use of different titania precursors, calcination rate, and ligand addition on the morphology, texture and phase content of synthesized mesoporous titania samples, parameters which, in turn, can play a key role in titania photocatalytic performances. The powders, obtained through the evaporation-induced self-assembly method, are characterized by means ofex situX-Ray Powder Diffraction (XRPD) measurements, N₂ physisorption isotherms and transmission electron microscopy. The precursors are selected basing on two different approaches: the acid-base pair, using TiCl₄ and Ti(OBu)₄, and a more classic route with Ti(OiPr)₄ and HCl. For both precursors, different specimens were prepared by resorting to different calcination rates and with and without the addition of acetylacetone, that creates coordinated species with lower hydrolysis rates, and with different calcination rates. Each sample was employed as photoanode and tested in the water splitting reaction by recording I-V curves and comparing the results with commercial P25 powders. The complex data framework suggests that a narrow pore size distribution, due to the use of acetylacetone, plays a major role in the photoactivity, leading to a current density value higher than that of P25.
Department of Chemistry and Pharmacy, University di Sassari and INSTM, Via Vienna 2, I-07100 Sassari, Italy. emasolo@uniss.it.
Elisabetta
E
Masolo
Department of Chemistry and Pharmacy, University di Sassari and INSTM, Via Vienna 2, I-07100 Sassari, Italy. manu-m-89@hotmail.it.
Manuela
M
Meloni
Department of Chemistry and Pharmacy, University di Sassari and INSTM, Via Vienna 2, I-07100 Sassari, Italy. sgarroni@uniss.it.
Sebastiano
S
Garroni
Department of Chemistry and Pharmacy, University di Sassari and INSTM, Via Vienna 2, I-07100 Sassari, Italy. mulas@uniss.it.
Gabriele
G
Mulas
Department of Chemistry and Pharmacy, University di Sassari and INSTM, Via Vienna 2, I-07100 Sassari, Italy. enzo@uniss.it.
Stefano
S
Enzo
Departament de Física, Universitat Autònoma de Barcelona, E-08193 Bellaterra, Spain. dolors.baro@uab.es.
Maria Dolors
MD
Baró
Servei de Microscòpia, Universitat Autònoma de Barcelona, E-08193 Bellaterra, Spain. Emma.Rossinyol@uab.cat.
Emma
E
Rossinyol
Helmholtz Centre Geesthacht, Institute for Materials Research, Max-Planck-Str. 1, 21502 Geesthacht, Germany. agnieszka.rzeszutek@hzg.de.
Agnieszka
A
Rzeszutek
Helmholtz Centre Geesthacht, Institute for Materials Research, Max-Planck-Str. 1, 21502 Geesthacht, Germany. iris.herrmann-geppert@hzg.de.|Helmut-Schmidt-University, Functional Materials, Holstenhofweg 85, 22043 Hamburg, Germany. iris.herrmann-geppert@hzg.de.
Iris
I
Herrmann-Geppert
Department of Chemistry and Pharmacy, University di Sassari and INSTM, Via Vienna 2, I-07100 Sassari, Italy. mpilo@uniss.it.
Maria
M
Pilo
EISA method; photocatalysis; powders; titania; water splitting