In this work, the porphyrin nanotubes were built by ionic self-assembly in acidic aqueous solution of two oppositely charged non-metal porphyrins, namely, the anionic meso-tetra (4-sulfonatophenyl) porphine dihydrochloride (TPPS 4) and cationic meso-tetra (4-pyridyl) porphine (T 4 MPyP). The electrostatic forces between these porphyrin blocks contribute to the formation of porphyrin aggregates in the form of nanosheets and nanotubes, enhance the structural stability of these nanostructures. The nanosheets thickness approximately varies in the range of 3-15 nm and the sheets diameter up to 1 micron. Using the TEM and SEM, it was revealed that the mechanism of nanotubes formation is based on the wrapping of nanosheets in multiwall cigar-like structures. The porphyrin nanotubes obtained are hollow structures with a length from 200 nm up to 1,000 nm and have a diameter in the range of 50-140 nm with 20-40 nm thick walls. TEM images confirm a hollow tubular structure of the aggregates.

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Nanostructured ZnO films were deposited on glass, quartz and Al on silicon mono-crystal Si (100) substrates by using the wire explosion technique. The growth process, structure and photoluminescence (PL) properties were studied by X-ray diffraction (XRD), UV -VIS spectroscopy, scanning electron (SEM) and atomic force microscopy (AFM) and photoluminescence measurements. X-ray diffraction measurements have shown that ZnO films are composed of (100), (002), (101) orientation crystallites. The post-deposition thermal treatment at 600 °C temperature in air has shown that the composite of Zn/ZnO film was fully oxidized to ZnO film. XRD spectra of the film deposited in oxygen atmosphere at room temperature presents high intensity dominating peak at 2θ = 36.32° corresponding to the (101) ZnO diffraction peak. The small fraction of the film (7%) correspond to (002) peak intensity at 2θ = 34.42°. This result indicates the good crystal quality of the film and hexagonal wurtzite-type structure deposited by zinc wire explosion. The SEM analysis shows that ZnO films presented different morphologies from fractal network to porous films depending on deposition conditions. AFM analysis revealed the grain size range from 50 to 500 nm. The deposited in air films have shown the weak PL peak at ~373 nm and a strong green luminescence band. The films deposited in oxygen atmosphere demonstrate increased UV band PL intensity and decreased intensity of green PL band. The obtained PL spectra are similar to powder ZnO and it correlates with the size of ZnO nanoparticles (10 -30 nm) measured by AFM. These results demonstrated that the wire explosion technique is a feasible method to produce high-quality ZnO nanocrystalline thin films and quantum dots.