Controlled Periodic Illumination Enhances Hydrogen Production by over 50% on Pt/TiO₂

Abstract

Efficient solar water photosplitting is plagued by large overpotentials of the HER and OER. Even with a noble metal catalyst, the hydrogen evolution reaction can be limited by the strong M–H bonding over some metals, such as Pt, Pd, and Rh, inhibiting hydrogen desorption. H absorption is regulated by the potential at the metal nanoparticles. Through controlled periodic illumination of a Pt/TiO 2 suspension, we hypothesized a fast variation of the photopotential that induced catalytic surface resonance on the metal, resulting in more than a 50% increase of the efficiency at frequencies higher than 80 Hz.

Thermo-photo catalysis: a whole greater than the sum of its parts

“…267,268 Thanks to the capability of light to modify the energetics of elementary steps, pulsed illumination enables surface oscillation between two adsorbate binding energies and thereby two rate-limiting steps at frequencies in resonance with reaction kinetics, which leads to an enhancement in catalytic performance. 126,269 Using CH 3 OH decomposition over Pt/SiO 2 catalyst as a probe reaction, the oscillation between a reactive surface limited by active site availability in dark (due to the strong bonding of CO to Pt) and a clean surface limited by activation of reactants (CH 3 OH) under light irradiation (Fig. 15a) contributed to a steady-state rate surpassing either static conditions (Fig.…”

Dynamically triggering photoreactions for high performance and efficiency

“…Recent publications report on the beneficial application of periodic or pulsed irradiation for hydrogen evolution, leading to an increase of the apparent reaction rate normalized to the time-averaged photon flux and thus to a higher efficiency of energy conversion. [39,40] Hence, research on the use of imposed dynamic irradiation, i.e. the desired temporal change of the incident photon flux represents a valuable strategy to develop high performance photoreactions.…”

Customizing New Titanium Dioxide Nanoparticles with Controlled Particle Size and Shape Distribution: A Feasibility Study Toward Reference Materials for Quality Assurance of Nonspherical Nanoparticle Characterization

“…The synthesis of the bipyramidal nanoparticles considered in this work (see Figure 1b) has been carried out with this last method, as described in several papers. [45,53,54] Figure 3. TiO 2 layers a) as coating synthesized by pulsed DC magnetron sputtering (after scratching it with a scalpel) and b) screen printed with the bipyramidal nanoparticles from Figure 1c as the starting material.…”

“…The synthesis of the bipyramidal nanoparticles considered in this work (see Figure 1b) has been carried out with this last method, as described in several papers. [ 45,53,54 ]…”