Mesoporous silica- and silicon-based materials ... - Helda - Helsinki.fi

4 Experimental
Detailed descriptions of the methods, suppliers of the materials and the equipment used in
this work can be found in the respective original publications (I-IV). Mesoporous siliconbased
materials (I, IV) were produced in the Laboratory of Industrial Physics, Department
of Physics and Astronomy, University of Turku, and ordered mesoporous silica materials
(II, III) in the Laboratory of Industrial Chemistry, Process Chemistry Centre, Åbo
Akademi.
4.1 Materials
4.1.1 Mesoporous particles (I-IV)
The PSi particles with various surface treatments were prepared from Si wafers (100), of
p+-type with resistivity values of 0.015–0.025 cm. The PSi was prepared by anodizing
the wafers in a HF (38%)ethanol (EtOH) mixture (HF:EtOH, 1:1). A current density of
50 mA/cm 2 was used to obtain a porosity of about 60% (I). Free-standing films were
obtained by abruptly increasing the current density and ball milling of the films produced
as-anodized PSi particles (I). The resulting powders were sieved with a 400 mesh sieve to
obtain particle size fraction