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A black aluminium film deposited by magnetron sputtering showed a high correlation of diffuse reflectivity with surface morphology and nitrogen content in plasma.

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The thermal stability of black aluminum (Black Al) films deposited on unheated fused silica substrates by pulsed DC magnetron sputtering is investigated. The deposited films have porous moth‐eye morphology and a relatively soft surface that can be easily damaged mechanically. Photothermally stimulated exoelectron emission (PTSE) spectra of the films have emission peaks at 180 and 300 °C, which can be associated with processes of aluminum recrystallization occurring at these temperatures. The total emitted charge of PTSE decreases according to a power law with each subsequent heating, indicating that the most pronounced structural changes on the film surface occur during its first annealing. The shape of the mechanically intact pores of the films does not change after heating. However, spiral‐shaped aluminum nanowires grow from scratches and abrasions on the film surface already after heating up to 200 °C due to the stress‐induced migration of aluminum atoms. When scratches are deliberately applied to the surface of an already annealed film, the nanowires do not grow when the film is reheated. The results of this study show that mechanically intact as‐deposited Black Al films are thermally stable up to temperatures of at least 400 °C.

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TiO2 nanosheets were modified by two different procedures (volume and surface modification) with 0.5 wt % of 57Fe toward Ti. In the case of volume modification, the 57Fe (in the form of 57Fe­(NO3)3·nH2O solution) was added at the beginning of preparation of TiO2 nanosheets while the surface modified sample was prepared from the aqueous suspension of undoped TiO2 nanosheets annealed at 800 °C and solution of 57Fe­(NO3)3·nH2O via impregnation method. The volume modified sample was later annealed at 650, 800, and 950 °C; no further annealing was done on the surface modified sample. Both types of prepared materials were characterized by electron microscopy, X-ray powder diffraction, surface and porosity measurements, thermal analysis, FTIR and Raman spectroscopies, and Mössbauer spectroscopy. Photocatalytic activity was characterized from the results of 4-chlorophenol (4-CP) decomposition. The surface modified sample exhibited highly effective photocatalytic decomposition of a model pollutant under UV irradiation. On the other hand, the volume modification proved to suppress photocatalytic activity under UV. The visible light activity of 4-CP decomposition was negligible for both volume and surface modified samples. Mössbauer spectroscopy measurements confirmed the presence of iron atoms in the TiO2 structure. The surroundings of the iron atoms exhibit a structure close to that of mixed oxides (Fe1–x Ti2–x O5 and Fe2–x Ti x O3) in solid solution.