How nice would it be to obtain the size distribution of a nanoparticle dispersion fast and without electron microscope measurements? UV-Vis-NIR spectrophotometry offers a very rapid solution; however, the spectra interpretation can be very challenging and needs to take into account the size distribution of the nanoparticles and agglomeration. This work suggests a Monte Carlo method for rapid fitting UV-Vis-NIR spectra using one or two size distributions starting from a dataset of precomputed spectra based on Mie theory. The proposed algorithm is tested on copper nanoparticles produced with Pulsed Laser Ablation in Liquid and on gold nanoparticles from the literature. The fitted distribution results are comparable with Transmission Electron Microscope results and, in some cases, reflect the presence of agglomeration.

In the field of sustainability, hydrogen (H2) is considered a clean fuel and a renewable energy source with no pollutant emissions. The production of H2 by water electrolysis is well-known among the scientific community. Still, alkaline electrolysis represents a challenging process and requires expensive materials have to be avoided in order to lower the impact of H2 production. This work deals with the production of copper (Cu) and nickel (Ni) nanoparticles (NPs) as catalysts for alkaline water splitting reactions. These NPs are synthesized using the pulsed laser ablation in liquid involving the ablation of Cu and Ni targets in methanol and ethanol. The morphological, structural, and compositional properties of the obtained NPs are studied. Then, a low amount of NPs-based catalyst (∼1μg/cm2) was loaded onto a nickel foam substrate and tested for both alkaline Hydrogen Evolution Reaction (HER) and Oxygen Evolution Reaction (OER). The best performance at 10 mA cm−2, in terms of overpotential (η), for OER was shown by Ni NPs, η = 327 mV, while for the HER, Cu NPs reached η = 211 mV at 10 mA cm−2 in aqueous 1M KOH. The ultra-low amount of the catalyst material makes these electrodes challenging in terms of mass activity [up to 14 A/mg at 10 mA cm−2] compared to the state of the art. In addition, the correlation between overpotential and the availability of electrons at the surface of the catalyst for H2 production was studied by using Mott–Schottky analysis.

Pulsed laser ablation in liquid is a very powerful technique that allows to synthesize colloidal solution of nanoparticles, starting from a target and a solvent, without waste. The performance of this process in terms of ablated mass per time depends on the laser fluence, the energy delivered per unit (or effective) area. Experimentally fluence evaluation is a tedious and indirect process, since the optical path passes through a lens and through an air–liquid interface, which is not easy to observe. In this work, a computational approach that provides the experimental parameters is developed, the laser ray paths inside the experimental apparatus are drawn, and the effective fluence on the target surface is evaluated. It aims to be an instrument to make predictions and help in the experimental setup tuning; moreover, the data obtained fit the theory developed for picosecond laser. The predictions can be extended to various real situations like a rotating fluid with a nonplane air–liquid surface.

Electrochemical Impedance Spectroscopy (EIS) is a widely used technique for characterizing the electrode–electrolyte interface. EIS analysis can be very complex and tedious. In this work, a fitting algorithm written in C is implemented on OriginPro software to avoid the data import/export operation and speed up the analysis. An automated fitting procedure that assigns the initial parameters is implemented for the simplest equivalent circuit. In addition, the possibility of using a custom error function is explored, with results comparable to that of reference software. The developed algorithm is tested on two different case studies.