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Papers by Vincenzo Balzano

Research paper thumbnail of Insights into the Photoelectrocatalytic Behavior of gCN-Based Anode Materials Supported on Ni Foams

Nanomaterials

Graphitic carbon nitride (gCN) is a promising n-type semiconductor widely investigated for photo-... more Graphitic carbon nitride (gCN) is a promising n-type semiconductor widely investigated for photo-assisted water splitting, but less studied for the (photo)electrochemical degradation of aqueous organic pollutants. In these fields, attractive perspectives for advancements are offered by a proper engineering of the material properties, e.g., by depositing gCN onto conductive and porous scaffolds, tailoring its nanoscale morphology, and functionalizing it with suitable cocatalysts. The present study reports on a simple and easily controllable synthesis of gCN flakes on Ni foam substrates by electrophoretic deposition (EPD), and on their eventual decoration with Co-based cocatalysts [CoO, CoFe2O4, cobalt phosphate (CoPi)] via radio frequency (RF)-sputtering or electrodeposition. After examining the influence of processing conditions on the material characteristics, the developed systems are comparatively investigated as (photo)anodes for water splitting and photoelectrocatalysts for the...

Research paper thumbnail of Exploring multielement nanogranular coatings to forestall implant-related infections

Frontiers in Cellular and Infection Microbiology

IntroductionAs we approach the post-antibiotic era, the development of innovative antimicrobial s... more IntroductionAs we approach the post-antibiotic era, the development of innovative antimicrobial strategies that carry out their activities through non-specific mechanisms could limit the onset and spread of drug resistance. In this context, the use of nanogranular coatings of multielement nanoparticles (NPs) conjugated to the surface of implantable biomaterials might represent a strategy to reduce the systemic drawbacks by locally confining the NPs effects against either prokaryotic or eukaryotic cells.MethodsIn the present study, two new multielement nanogranular coatings combining Ag and Cu with either Ti or Mg were synthesized by a gas phase physical method and tested against pathogens isolated from periprosthetic joint infections to address their potential antimicrobial value and toxicity in an in vitro experimental setting.ResultsOverall, Staphylococcus aureus, Staphylococcus epidermidis and Escherichia coli displayed a significantly decreased adhesion when cultured on Ti-Ag-Cu...

Research paper thumbnail of Synergistic Effect of Sn and Fe in Fe–Nx Site Formation and Activity in Fe–N–C Catalyst for ORR

ACS Applied Materials & Interfaces

Iron−nitrogen−carbon (Fe−N−C) materials emerged as one of the best non-platinum group material (n... more Iron−nitrogen−carbon (Fe−N−C) materials emerged as one of the best non-platinum group material (non-PGM) alternatives to Pt/C catalysts for the electrochemical reduction of O 2 in fuel cells. Co-doping with a secondary metal center is a possible choice to further enhance the activity toward oxygen reduction reaction (ORR). Here, classical Fe−N−C materials were co-doped with Sn as a secondary metal center. Sn−N−C according to the literature shows excellent activity, in particular in the fuel cell setup; here, the same catalyst shows a nonnegligible activity in 0.5 M H 2 SO 4 electrolyte but not as high as expected, meaning the different and uncertain nature of active sites. On the other hand, in mixed Fe, Sn−N−C catalysts, the presence of Sn improves the catalytic activity that is linked to a higher Fe− N 4 site density, whereas the possible synergistic interaction of Fe−N 4 and Sn−N x found no confirmation. The presence of Fe−N 4 and Sn−N x was thoroughly determined by extended X-ray absorption fine structure and NO stripping technique; furthermore, besides the typical voltammetric technique, the catalytic activity of Fe−N−C catalyst was determined and also compared with that of the gas diffusion electrode (GDE), which allows a fast and reliable screening for possible implementation in a full cell. This paper therefore explores the effect of Sn on the formation, activity, and selectivity of Fe−N−C catalysts in both acid and alkaline media by tuning the Sn/Fe ratio in the synthetic procedure, with the ratio 1/2 showing the best activity, even higher than that of the iron-only containing sample (j k = 2.11 vs 1.83 A g −1). Pt-free materials are also tested for ORR in GDE setup in both performance and durability tests.

Research paper thumbnail of The Role of Substrate on Thermal Evolution of Ag/TiO2 Nanogranular Thin Films

Nanomaterials, 2021

In multicomponent thin films, properties and functionalities related to post-deposition annealing... more In multicomponent thin films, properties and functionalities related to post-deposition annealing treatments, such as thermal stability, optical absorption and surface morphology are typically rationalized, neglecting the role of the substrate. Here, we show the role of the substrate in determining the temperature dependent behaviour of a paradigmatic two-component nanogranular thin film (Ag/TiO2) deposited by gas phase supersonic cluster beam deposition (SCBD) on silica and sapphire. Up to 600 °C, no TiO2 grain growth nor crystallization is observed, likely inhibited by the Zener pinning pressure exerted by the Ag nanoparticles on the TiO2 grain boundaries. Above 600 °C, grain coalescence, formation of However, the two substrates steer the evolution of the film morphology and optical properties in two different directions. anatase and rutile phases and drastic modification of the optical absorption are observed. On silica, Ag is still present as NPs distributed into the TiO2 matrix...

Research paper thumbnail of Insights into the Photoelectrocatalytic Behavior of gCN-Based Anode Materials Supported on Ni Foams

Nanomaterials

Graphitic carbon nitride (gCN) is a promising n-type semiconductor widely investigated for photo-... more Graphitic carbon nitride (gCN) is a promising n-type semiconductor widely investigated for photo-assisted water splitting, but less studied for the (photo)electrochemical degradation of aqueous organic pollutants. In these fields, attractive perspectives for advancements are offered by a proper engineering of the material properties, e.g., by depositing gCN onto conductive and porous scaffolds, tailoring its nanoscale morphology, and functionalizing it with suitable cocatalysts. The present study reports on a simple and easily controllable synthesis of gCN flakes on Ni foam substrates by electrophoretic deposition (EPD), and on their eventual decoration with Co-based cocatalysts [CoO, CoFe2O4, cobalt phosphate (CoPi)] via radio frequency (RF)-sputtering or electrodeposition. After examining the influence of processing conditions on the material characteristics, the developed systems are comparatively investigated as (photo)anodes for water splitting and photoelectrocatalysts for the...

Research paper thumbnail of Exploring multielement nanogranular coatings to forestall implant-related infections

Frontiers in Cellular and Infection Microbiology

IntroductionAs we approach the post-antibiotic era, the development of innovative antimicrobial s... more IntroductionAs we approach the post-antibiotic era, the development of innovative antimicrobial strategies that carry out their activities through non-specific mechanisms could limit the onset and spread of drug resistance. In this context, the use of nanogranular coatings of multielement nanoparticles (NPs) conjugated to the surface of implantable biomaterials might represent a strategy to reduce the systemic drawbacks by locally confining the NPs effects against either prokaryotic or eukaryotic cells.MethodsIn the present study, two new multielement nanogranular coatings combining Ag and Cu with either Ti or Mg were synthesized by a gas phase physical method and tested against pathogens isolated from periprosthetic joint infections to address their potential antimicrobial value and toxicity in an in vitro experimental setting.ResultsOverall, Staphylococcus aureus, Staphylococcus epidermidis and Escherichia coli displayed a significantly decreased adhesion when cultured on Ti-Ag-Cu...

Research paper thumbnail of Synergistic Effect of Sn and Fe in Fe–Nx Site Formation and Activity in Fe–N–C Catalyst for ORR

ACS Applied Materials & Interfaces

Iron−nitrogen−carbon (Fe−N−C) materials emerged as one of the best non-platinum group material (n... more Iron−nitrogen−carbon (Fe−N−C) materials emerged as one of the best non-platinum group material (non-PGM) alternatives to Pt/C catalysts for the electrochemical reduction of O 2 in fuel cells. Co-doping with a secondary metal center is a possible choice to further enhance the activity toward oxygen reduction reaction (ORR). Here, classical Fe−N−C materials were co-doped with Sn as a secondary metal center. Sn−N−C according to the literature shows excellent activity, in particular in the fuel cell setup; here, the same catalyst shows a nonnegligible activity in 0.5 M H 2 SO 4 electrolyte but not as high as expected, meaning the different and uncertain nature of active sites. On the other hand, in mixed Fe, Sn−N−C catalysts, the presence of Sn improves the catalytic activity that is linked to a higher Fe− N 4 site density, whereas the possible synergistic interaction of Fe−N 4 and Sn−N x found no confirmation. The presence of Fe−N 4 and Sn−N x was thoroughly determined by extended X-ray absorption fine structure and NO stripping technique; furthermore, besides the typical voltammetric technique, the catalytic activity of Fe−N−C catalyst was determined and also compared with that of the gas diffusion electrode (GDE), which allows a fast and reliable screening for possible implementation in a full cell. This paper therefore explores the effect of Sn on the formation, activity, and selectivity of Fe−N−C catalysts in both acid and alkaline media by tuning the Sn/Fe ratio in the synthetic procedure, with the ratio 1/2 showing the best activity, even higher than that of the iron-only containing sample (j k = 2.11 vs 1.83 A g −1). Pt-free materials are also tested for ORR in GDE setup in both performance and durability tests.

Research paper thumbnail of The Role of Substrate on Thermal Evolution of Ag/TiO2 Nanogranular Thin Films

Nanomaterials, 2021

In multicomponent thin films, properties and functionalities related to post-deposition annealing... more In multicomponent thin films, properties and functionalities related to post-deposition annealing treatments, such as thermal stability, optical absorption and surface morphology are typically rationalized, neglecting the role of the substrate. Here, we show the role of the substrate in determining the temperature dependent behaviour of a paradigmatic two-component nanogranular thin film (Ag/TiO2) deposited by gas phase supersonic cluster beam deposition (SCBD) on silica and sapphire. Up to 600 °C, no TiO2 grain growth nor crystallization is observed, likely inhibited by the Zener pinning pressure exerted by the Ag nanoparticles on the TiO2 grain boundaries. Above 600 °C, grain coalescence, formation of However, the two substrates steer the evolution of the film morphology and optical properties in two different directions. anatase and rutile phases and drastic modification of the optical absorption are observed. On silica, Ag is still present as NPs distributed into the TiO2 matrix...