In this work, superhydrophobic nickel cobalt hydroxide films were electrodeposited on silicon nanowires array (SiNWs). The superhydrophobicity was attributed to the morphology of NiO-Co(OH)2 which ...was deposited as urchin–like structures composed of many nanorods radially grown from the center. It was observed that the wettability decreases as these surfaces were irradiated with visible light. Indeed, the contact angle decreases from 158° to 7° after 1 h of visible light illumination. This behavior has allowed to improve the photocatalytic efficiency during the photodegradation process of rhodamine B (RhB). A full degradation was achieved after 1 h of visible light irradiation.
•A new NiO-Co(OH)2/SiNWs nanocomposite was synthesized.•A superhydrophobic urchin-like structure NiO-Co(OH)2 was grown on SiNWs.•Photo-induced wettability of NiO-Co(OH)2/SiNWs under visible light illumination.•Enhanced photodegradation of Rhodamine B under visible light.
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•The tartrazine photodegradation by modified and unmodified SiNWs was studied.•The modification of SiNWs was carried out by nanoparticles of Pt, Pd, Ag, Au and Cu.•The Cu-modified ...SiNWs give the highest photocatalytic activity.•The enhancement of the photocatalytic activity by the treatment of Cu-modified SiNWs with H2O2 is shown.
In this work we investigated the tartrazine photodegradation by modified and unmodified silicon nanowires (SiNWs). SiNWs were elaborated by one-step metal-assisted electroless chemical etching of silicon substrate in HF/AgNO3 aqueous solution. The modification of SiNWs was carried out by nanoparticles of platinum, palladium, silver, gold and copper in chemical solutions of PtO2, PdCl2, AgNO3, AuCl3 and CuSO4, respectively. The results show that Cu-modified silicon nanowires give the highest photocatalytic activity compared to the unmodified SiNWs and SiNWs modified with nanoparticles of Au, Pt, Pd and Ag.
In this work, superhydrophobic nickel cobalt hydroxide films were electrodeposited on silicon nanowires array (SiNWs). The superhydrophobicity was attributed to the morphology of NiO-Co(OH)2 which ...was deposited as urchin–like structures composed of many nanorods radially grown from the center. It was observed that the wettability decreases as these surfaces were irradiated with visible light. Indeed, the contact angle decreases from 158° to 7° after 1 h of visible light illumination. This behavior has allowed to improve the photocatalytic efficiency during the photodegradation process of rhodamine B (RhB). A full degradation was achieved after 1 h of visible light irradiation.
Nanocrystalline Fe
90
Ni
10
alloys were synthesized by mechanical alloying, starting from a powder mixture of elemental Fe and Ni. The phase evolution and magnetic properties were investigated, as a ...function of milling time, using the X-ray diffraction (XRD), the vibrating sample magnetometer (VSM), and the
57
Fe Mössbauer spectroscopy. From XRD results, we concluded the formation, after 13 h of milling, of a disordered phase
α
-Fe(Ni) (bcc). It has been shown that the increase of milling time decreases the crystallites size and increases the microstrains and the lattice parameter. When the crystallites size decreases, the coercive field,
H
c
, decreases first, then increases and finally reaches a constant value of about 26 Oe. During the periode of the alloy formation, the saturation magnetization,
M
s
, increases with decreasing crystallite size and reaches the highest value of 212 emu/g after 27 h of milling, then,
M
s
remains constant up to 48 h of milling. The adjustment of Mössbauer spectra revealed that the fraction of the (bcc)
α
-Fe(Ni) phase increased with milling time. After 13 h of milling, only the (bcc)
α
-Fe(Ni) phase is observed.
