Jorge Medina-Valtierra

A catalytic application of Cu2O and CuO films deposited over fiberglass

Abstract With the purpose of utilizing copper oxides over fiberglass as a novel catalyst material in oxidation reactions, we have used the chemical vapor deposition of 2,4-pentanedionate copper(II) as a precursor and fiberglass as substrate. The deposition of copper oxides was achieved in a horizontal-flow reactor using O2 as carrier-reactant gas at several deposition temperatures. Copper species deposited on fiberglass were characterized by X-ray diffraction (XRD), UV–visible spectrophotometry (UV–VIs) and scanning electronic microscopy (SEM) techniques. The fiberglass coated with copper oxides showed a catalytic activity for the oxidation of ethanol into a stream of air at different temperatures in a pulse microreactor.

Chemical vapor deposition of 6CuO·Cu2O films on fiberglass

Abstract To coat fiberglass with copper oxides, in particular with the paramelaconite structure 6CuO·Cu 2 O, we have used the chemical vapor deposition (CVD) procedure of a copper precursor. The deposition of copper oxides was done using a horizontal-flow reactor, 2,4-pentanedionate copper(II) as precursor and O 2 as carrier-reactant gas at several deposition temperatures. In order to establish a correlation between experimental parameters and the resulting copper species, as well as film quality, the samples that were produced, were evaluated using techniques such as X-ray diffraction (XRD), visible spectrophotometry, scanning electronic microscopy (SEM) and atomic force microscopy (AFM). The most important result is that 6CuO·Cu 2 O thin films are obtained over a short range of deposition temperatures. The film growth of this copper phase occurred in the [202] and [004] directions.

Self-Cleaning Test of Doped Anatase-Coated Glass Plates

Doped anatase thin films on glass were deposited by ultra-spinning from titanium isopropoxide-based sol-gels. To test the self-cleaning properties of anatase-coated glass, crystalline fluoranthene, a polycyclic aromatic compound, was sprayed over the glass and then irradiated using a 365 nm UV source. This anthropogenic contaminant was removed until 98 wt.% at 140 h of irradiation time with the 2 wt.% zinc ferrite-doped anatase film. The fluoranthene proportion degraded on anatase-free glass was much lower than with anatase coating giving only 12% for an irradiation time of 140 h. In this form, the coated-glass transparency was recovered almost totally at this irradiation time for the doped anatase film mentioned, which did not occur with anatase-free glass, even after more than 400 h of UV irradiation. A correlation was found between the total weight losses of the solid compound and the intensity of the Raman vibration at 671 cm-1 during photocatalytic degradation. After 140 h of irradiation, while the presence of fluoranthene is not detected by Raman spectroscopy, glass plate presented ultra-thin zones of degradation products. Thus, the removal of these intermediate products deposited on glass was directly measured by means of weight difference. The self-cleaning properties of doped anatase coating on window glass could have a positive influence on outdoor and indoor air quality. In this work, degradation mechanisms and intermediate products were not discussed or identified.