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In this work, we report how manganese phthalocyanine (MnPc) films obtained using the ultrasonic spray–pyrolysis technique at 40 °C deposited on glass substrate subjected to thermal annealing at 100 °C and 120 °C. The MnPc films were characterized using UV/Vis spectroscopy, Raman spectroscopy, X-Ray Diffraction (XRD), and Scanning Electron Microscopy (SEM). The absorption spectra of the MnPc films were studied in a wavelength range from 200 to 850 nm, where the characteristic bands of a metallic phthalocyanine known as B and Q bands were observed in this range of the spectrum. The optical energy band (Eg) was calculated using the Tauc equation. It was found that, for these MnPc films, the Eg has the values of 4.41, 4.46, and 3.58 eV corresponded to when they were deposited, annealing at 100 °C and 120 °C, respectively. The Raman spectra of the films showed the characteristic vibrational modes of the MnPc films. In the X-Ray diffractograms of these films, the characteristic diffraction peaks of a metallic phthalocyanine are observed, presenting a monoclinic phase. The SEM images of these films were studied in a cross-section obtaining thicknesses of 2 μm for the deposited film and 1.2 μm and 0.3 μm for the annealed films at 100 °C and 120 °C. Additionally, in the SEM images of these films, average particle sizes ranging from 4 to 0.041 µm were obtained. The results agree with those reported in the literature for MnPc films deposited by performing other techniques.

Thin films of nanocomposite of zinc oxide&ndash, reduced graphene oxide (ZnO-rGO) deposited on soda-lime glass substrates were prepared using ultrasonic spray pyrolysis (USP) at 460 &deg, C. The preparation process does not use harsh acids and is environmentally friendly. The deposition period of 2, 3.5 and 5 min resulted in compact, uniform samples with thicknesses of 148, 250 and 365 nm, respectively. After performing structural, morphological, optical and electrical characterization of the prepared nanocomposite, an influence of the deposition time on the physical properties of the obtained films was determined. TEM analyses indicate that the ZnO-rGO nanocomposite presents ZnO nanoparticles anchored on graphene sheets, while XRD, X-ray Photoelectron Spectroscopy (XPS) and Raman results show the presence of a ZnO phase in the ZnO-rGO films. HR-SEM studies showed changes of the ZnO-rGO thin films morphology due to the incorporation of graphene into the ZnO films. Here, the particles of ZnO are similar to small grains of rice and graphene films have the appearance of a little &ldquo, rose&rdquo, As the thickness of the film increases with deposition time, it reduces the structure of resistance of the nanocomposite thin films to 135 &Omega, In addition, the optical transmission of the thin films in the visible region resulted affected. Here, we report a simple methodology for the preparation of ZnO-rGO nanocomposite thin films.

The search for novel materials and the development of improved processes for water purification have attracted the interest of researchers worldwide and the use of titanium dioxide in photocatalytic processes for the degradation of organic pollutants contained in water has been one of the benchmarks. Compared to crystalline titanium dioxide (cTiO2), the amorphous material has the advantages of having a higher adsorption capacity and being easier to dope with metal and non-metal elements. In this work, we take advantage of these two features to improve its photocatalytic properties in the degradation of Rhodamine B. The structural characterization by XRD analysis gives evidence of its amorphous nature and the SEM micrographs portray the disc morphology of 300 nm in diameter with heterogeneous grain boundaries. The degradation of Rhodamine B tests with the amorphous TiO2 using visible light confirm its improved catalytic activity compared to that of a commercial product, Degussa P25, which is a well-known crystalline material.

The fundamental aspects of the manufacturing of gold nanoparticles (AuNPs) are discussed in this review. In particular, attention is devoted to the development of a simple and versatile method for the preparation of these nanoparticles. Eco-friendly synthetic routes, such as wet chemistry and biosynthesis with the aid of polymers, are of particular interest. Polymers can act as reducing and/or capping agents, or as soft templates leading to hybrid nanomaterials. This methodology allows control of the synthesis and stability of nanomaterials with novel properties. Thus, this review focus on a fundamental study of AuNPs properties and different techniques to characterize them, e.g., Transmission Electron Microscopy (TEM), Atomic Force Microscopy (AFM), UV-Visible spectroscopy, Dynamic Light Scattering (DLS), X-Ray Diffraction (XRD), X-Ray Photoelectron Spectroscopy, Small-angle X-Ray Scattering (SAXS), and rheology. Recently, AuNPs obtained by “green” synthesis have been applied in catalysis, in medicine, and as antibacterials, sensors, among others.