Mónica Barroso

  • Citations Per Year
Learn More
This paper addresses the origin of the decrease in the external electrical bias required for water photoelectrolysis with hematite photoanodes, observed following surface treatments of such electrodes. We consider two alternative surface modifications: a cobalt oxo/hydroxo-based (CoO(x)) overlayer, reported previously to function as an efficient water(More)
We calculate energy barriers of atom- and proton-transfer reactions in hydrogen-bonded complexes in the gas phase. Our calculations do not involve adjustable parameters and are based on bond-dissociation energies, ionization potentials, electron affinities, bond lengths, and vibration frequencies of the reactive bonds. The calculated barriers are in(More)
Transient absorption spectroscopy was used to probe the dynamics of photogenerated charge carriers in α-Fe(2)O(3)/CoO(x) nanocomposite photoelectrodes for water splitting. The addition of cobalt-based electrocatalysts was observed to increase the lifetime of photogenerated holes in the photoelectrode by more than 3 orders of magnitude without the(More)
Competition between charge recombination and the forward reactions required for water splitting limits the efficiency of metal-oxide photocatalysts. A key requirement for the photochemical oxidation of water on both nanostructured α-Fe(2)O(3) and TiO(2) is the generation of photoholes with lifetimes on the order of milliseconds to seconds. Here we use(More)
Transient absorption spectroscopy on the μs-s time scale is used to monitor the yield and decay dynamics of photogenerated holes in nanocrystalline hematite photoanodes. In the absence of a positive applied bias, these holes are observed to undergo rapid electron-hole recombination. The application of a positive bias results in the generation of long-lived(More)
Steady-state fluorescence of 4'-dimethylamino-3-hydroxyflavone (DMA3HF) was observed in supercritical carbon dioxide (scCO(2)). Excited-state intramolecular proton transfer (ESIPT) occurs resulting in two well-separated emission bands corresponding to the normal and tautomer forms. As the scCO(2) density exceeds 0.7 g/mL, the relative intensity of the two(More)
Time-resolved photoacoustic calorimetry (PAC) allows the measurement of lifetimes and energy fractions of molecular nonradiative deactivation processes, as well as structural volume changes associated with such processes. The photoinduced acoustic wave generated by a given photochemical sample, E(t), is the result of the convolution between the heat(More)
We calculate transition-state energies of atom-transfer reactions from reaction energies, electrophilicity indices, bond lengths, and vibration frequencies of the reactive bonds. Our calculations do not involve adjustable parameters and uncover new patterns of reactivity. The generality of our model is demonstrated comparing the vibrationally adiabatic(More)
The reaction path of the intersecting-state model is used in transition-state theory with the semiclassical correction for tunneling (ISM/scTST) to calculate the rates of proton-transfer reactions from hydrogen-bond energies, reaction energies, electrophilicity indices, bond lengths, and vibration frequencies of the reactive bonds. ISM/scTST calculations do(More)
Nanocrystalline TiO2 and reduced graphene oxide (TiO2/RGO) composite films were prepared by combining a sol-gel method with hydrothermal treatment, employing titanium isopropoxide (Ti(O(i)Pr)4) and graphene oxide (GO) as starting materials. Although several reports in the literature have explored the benefits of RGO addition in titania films for(More)