Simultaneous electrocatalytic Pt-nanoparticle synthesis and decoration of Vulcan XC-72 carbon black substrate was achieved in a novel one-step-process, combining galvanostatic pulsed electrodeposition and pulsed ultrasonication with high power, low-frequency (20kHz) ultrasound. Aqueous chloroplatinic acid precursor baths, as well as carbon black suspensions in the former, were examined and decoration was proven by a combination of characterization methods, namely: dynamic light scattering, transmission electron microscopy, scanning electron microscopy with EDX-analysis and cyclic voltammetry. In particular, PVP was shown to have a beneficial stabilizing effect against free nanoparticle aggregation, ensuring narrow size distributions of the nanoparticles synthesized, but is also postulated to prevent the establishment of a strong metal-substrate interaction. Current pulse amplitude was identified as the most critical nanoparticle size-determining parameters, while only small size particles, under 10nm, appeared to be attached to carbon black.

Highlights Surface decoration of micro-sized TiO 2 by means of high-energy ultrasound AbstractAlthough the TiO 2 is one of the most promising materials for its photocatalytic potential related to the pollution abatement, it strongly suffers from the low photocatalytic activity if it is used under visible light and not under UV light. Among the various possible modifications, the surface decoration with metal or metal oxides NPs can be a good strategy to increase the potential of TiO 2 in the visible range. In this paper, a sonochemical method that exploits the use of high-energy ultrasounds is suggested to obtain this surface decoration. The support is a commercial and micrometric TiO 2 , cheaper and easier to handling than the nanometric P25. Samples were tested on the photodegradation of toluene and acetone in a gas phase system, using both the UV and LED lamp.

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