arXiv subjects

Gianlorenzo Bussetti

Publications and source records attributed to Gianlorenzo Bussetti.

4 recordsLinked to original sources

arXiv2026

Magnetron Sputtering Formation of Nanoparticles from Natural Olivine Rock for Atmospheric CO2 Capture

The two-birds-one-stone mineralization of CO2 by olivine, is a promising method to both capture carbon directly from the atmosphere and at the same time locking it for storage or utilization. Converting olivine to the nanoscale considerably enhances the kinetics without the need for high temperatures or pressures. Here we present the fabrication of olivine nanoparticles from a natural rock that were fabricated in a gas aggregation magnetron nanoparticle generator. The nanoparticle yield was optimized by enhancing the argon plasma sputter plasma by hydrogen introduction and varying the aggregation distance. The hysteresis of the argon sputter plasma with respect to power is a promising property towards energy efficiency. The formation of well-defined olivine nanoparticles and their subsequent absorption of atmospheric CO2 was confirmed by a suite of techniques. The olivine sputter target surface revealed an intricate interplay between the sputter plasma and olivine composition in terms of crystallinity and morphology. More broadly, this work forms the next step in the practical application of Olivine nanoparticles for economical carbon capture and storage, it also is the starting point for the use of this specific nanoparticle technology for mineral-to-nanoparticle conversion.

physics.gen-ph↗

arXiv2025

Wettability and sp2/sp3 ratio effects on supercapacitor performance of N-doped hydrogenated amorphous Carbon Nanofoam

Pulsed laser-deposited amorphous carbon nanofoams are potential candidate for electrochemical energy storage applications due to ultra-light weight, large volumetric void fractions, and co-existence of sp, sp2 and sp3 carbon hybridization. It is known that charge storage in carbon nanostructures containing disordered sp2-domains is determined by their wettability, surface area, and porosity. However, their charge-storage performance is limited to the areal capacitance of the order of a few mF/cm2. We enhanced the supercapacitor performance of nitrogen-doped amorphous carbon nanofoam by engineering its wettability and sp2-C/sp3-C ratio by vacuum annealing. The specific capacitance was enhanced by about fifty times and the device voltage increased from 0.8 to 1.1 V compared to as-grown carbon nanofoam. In addition, we examined for the first time the initial increase in specific capacitance of the aqueous symmetric supercapacitor with respect to the scan rate, employing in-situ measurements coupling Raman spectroscopy and electrochemistry. We attribute this effect, observed but generally not explained in previous works in the literature, to the electrochemical activation induced by structural changes during the charge storage performance. This optimization of pulsed laser deposited carbon nanofoam may open an avenue for fabricating lightweight and porous nanostructures for advanced macro-to-micro-supercapacitor devices.

cond-mat.mtrl-sci↗

arXiv2025

Low-density functionalized amorphous carbon nanofoam as binder-free Supercapacitor electrode

Nanoporous carbon materials containing small domains of sp2-carbon with highly disordered structures are promising for supercapacitor applications. Herein, we synthesize amorphous carbon nanofoam with 98% volumetric void fraction and low mass density of around 30 mg/cm3 by pulsed laser deposition at room temperature. With the unavoidable oxygen functional groups on the nanoporous surface, carbon nanofoam and nitrogen-functionalized carbon nanofoams are directly grown on the desired substrate under different background gases (Ar, N2, N2-H2), and employed as supercapacitor electrodes. Among the background gases used in synthesis, the use of nitrogen yields nanofoam with higher thickness and more N-content with higher graphitic-N. From the test of amorphous carbon nanofoam supercapacitor device, nitrogenated amorphous carbon electrode shows a higher areal capacitance of 4.1 mF/cm2 at 20 mV/s in aqueous electrolyte, a better capacitance retention at higher current, and excellent cycle stability (98%) over 10000 charge-discharge cycles are achieved compared to not-functionalized counterpart prepared under Ar background gas (2.7 mF/cm2 and cycle stability of 88%).

physics.app-ph↗

arXiv2024

Ballistic-aggregated Carbon Nanofoam in Target-side of Pulsed Laser Deposition for Energy Storage Applications

In pulsed laser deposition, along the traditionally exploited deposition on the front-side of the plasma-plume, a coating forms on the surface of the target as well. For reproducibility, this residue is usually cleaned and discarded. Here we instead investigate the target-side coated materials and employ them as a binder-free supercapacitor electrode. The ballistic-aggregated, target-side nanofoam is compact and features a larger fraction of sp2-carbon, higher nitrogen content with higher graphitic-N and lower oxygen content with fewer COOH groups than that of diffusive-aggregated conventional nanofoams. They are highly hydrogenated graphite-like amorphous carbon and superhydrophilic. The resulting symmetric micro-supercapacitor delivers higher volumetric capacitance of 522 mF/cm3 at 100 mV/s and 104% retention after 10000 charge-discharge cycles over conventional nanofoam (215 mF/cm3 and 85% retention) with an areal capacitance of 134 μF/cm2 at 120 Hz and ultrafast frequency response. Utilizing the normally discarded target-side material can therefore enable high performing devices while reducing waste, cost and energy input per usable product. leading towards a greater sustainability on nanomaterials synthesis and deposition techniques.

physics.app-ph↗