Browsing by Author "Castillo, Francisco"

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    CdTe quantum dots modified electrodes ITO-(Polycation/QDs) for carbon dioxide reduction to methanol
    (ELSEVIER, 2020) Guzman, Diego; Isaacs, Mauricio; Tsukuda, Tatsuya; Yamazoe, Seiji; Takahata, Ryo; Schrebler, Ricardo; Burgos, Ana; Osorio Roman, Igor; Castillo, Francisco
    The present work describes the characterization by atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and electrochemical techniques of ITO modified electrodes with electrostatic assemblies (Polycation/Quantum Dots) and their use in the electro- and photoelectrocatalytic reduction of CO2. These assemblies were prepared with polycations poly-diallyldimethylammonium (PD) and poly-(2-trimethylammonium) ethyl methacrylate (PM) and nanocrystals of CdTe of 2.77 nm (Q2). The size of the nanocrystals was controlled by the synthesis reflux time and incorporated by electric field directed Layer-by-Layer assembly method (EFDLA). The polycations were characterised by NMR measurements; showing important effects on the electrostatic assemblies. PM modified electrodes, with its lower rigidity, exhibited less roughness than the PD modified electrodes, 8.0 nm versus 32.8 nm, and higher heterogeneity in its surface composition. Higher resistance to the charge transfer and time constants were obtained with PMQ2 modified electrode, 63.8 Omega cm(-2) and 2.69 ms versus 49.30 Omega cm(-2) and 1.3 ms for PDQ2. The electro- and photoelectro properties for CO 2 reduction were studied through j-E curves and potential controlled electrolysis. Modified surfaces were active toward the reduction of CO2, with a positive shift of the activity between darkness and irradiation conditions, 0.050 V with PDQ2 and 0.450 V with PMQ2. The main product of the CO2 reduction was CH3OH, with traces of CO and HCOOH. The PM modified electrodes with QDs of 2.77 nm presented a selective behaviour for the production of CH3OH.
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    Discharge formation in fast pulsed capillary discharges
    (IEEE, 2002) Favre Domínguez, Mario; Choi, Peter; Leñero Marchant, Ana María; Castillo, Francisco; Suzuki Vidal, Francisco Andrés; Chuaqui Kettlun, Hernán; Mitchell, Ian H.; Wyndham Hodder, Edmund Sydenham
    We present a study of discharge formation in a fast pulsed capillary discharge operated in Argon or Methane, in a 50 mm long, 1.6 mm internal diameter capillary, at −15 kV applied voltage. A pressure gradient is used along the capillary, with pressures between 0.2 and 1.0 Torr in the cathode region and a pressure one tenth lower in the anode side. The diagnostics include a capacitive probe array, Faraday cup and beam-target scintillator-photomultiplier detectors. It is found that following the emission of electron beams from the hollow cathode region, a fast ionization wave propagates from the cathode towards the anode, with characteristic velocities of the order of 106 to 107 m/s. The propagation of the ionization front is assisted by the electron beams, which reach a peak current of around 200 mA.
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    Genetic algorithms for batch sizing and production scheduling
    (2015) Castillo, Francisco; Gazmuri S., Pedro
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    Novel and Convenient Synthesis of 2,7-Dialkyl-1,8-dihydro- as -indacenes
    (2019) Faúndez Gutiérrez, Rodrigo Esteban; Castillo, Francisco; Preite, Marcelo Daniel; Schott Verdugo, Eduardo Enrique; Zarate, Ximena; Manríquez M., Juan Manuel; Molins, Elies; Morales-Verdejo, César; Chavez, Ivonne