Nanomaterials | Behind the Paper: “Ni–Cu Templates and Freestanding 3D Graphene Foams”
In this Behind the Paper interview, we speak with Dr. Alessandro Gradone, the corresponding author of a recent article published in Nanomaterials (ISSN 2079-4991). Dr. Gradone shares his perspective on the motivation behind the study, the preparation and evolution of porous Ni–Cu templates, the challenges of producing freestanding three-dimensional graphene foams, and their potential applications in electrochemical and photoelectrochemical devices.
“Freestanding 3D Multilayer Graphene Foams from Nanotextured Ni-Cu Templates”
by Jaimon Chonedan Johnson, Nicolò Galvani, Piera Maccagnani, Alessandro Surpi, Nicola Gilli, Rita Rizzoli, Alessandro Gradone, Giulia Lorusso, Fabiola Liscio and Vittorio Morandi
Nanomaterials 2026, 16(15), 950; https://doi.org/10.3390/nano16150950
Dr. Alessandro Gradone is a researcher at CNR-ISMN in Bologna, with a background in chemistry and expertise in advanced electron microscopy. His research focuses on the structural and functional characterization of nanomaterials through TEM/STEM and SEM, including in situ and operando approaches. He is particularly interested in correlating nanoscale structure, composition, and morphology with the physicochemical properties and functional performance of materials. His work integrates experimental design, specimen preparation, electron microscopy, and complementary analytical techniques, often within interdisciplinary collaborations. His research interests include photoactive nanomaterials, catalytic systems, and functional materials for energy conversion, with particular emphasis on establishing meaningful structure–property relationships.
The following is an interview with Dr. Gradone:
1. Previous studies have demonstrated the fabrication of graphene foams using Ni–Cu templates. What motivated your team to focus specifically on the evolution of the metal template before graphene growth?
Although graphene foams grown on Ni–Cu templates have been investigated previously, most studies have focused mainly on graphene growth conditions. We wanted to examine the metallic scaffold itself, because it is not simply a passive support. Its morphology, composition, grain structure, and mechanical stability strongly influence the architecture and integrity of the resulting graphene network. Our objective was therefore to understand how thermal pre-annealing modifies the porous Ni–Cu template before chemical vapor deposition and how these changes affect graphene formation. Establishing this relationship allowed us to identify the template evolution as a key parameter for improving the structural stability and reproducibility of freestanding graphene foams.
2. What considerations led you to choose hydrogen-bubble-assisted electrodeposition on copper foil as the starting point for preparing the porous templates?
We selected hydrogen-bubble-assisted electrodeposition because it provides a relatively simple, cost-effective, and scalable method for producing highly porous, interconnected metallic structures. During electrodeposition, hydrogen bubbles act as dynamic templates, creating a three-dimensional network without requiring additional sacrificial materials or complex fabrication steps. The morphology of the deposit can also be adjusted through parameters such as current density, deposition time, and electrolyte composition. Copper foil was chosen as the starting substrate because of its high electrical conductivity and compatibility with Ni–Cu deposition and subsequent graphene growth. Overall, this approach offered an effective route for preparing porous templates with the architecture required for freestanding graphene foams.
3. One of the main findings is the difference in structural stability between the samples pre-annealed for 1 and 3 hours. What did this comparison reveal to you about the factors governing the formation of freestanding graphene networks?
The comparison between the 1-hour and 3-hour pre-annealed samples showed that freestanding graphene formation depends on a balance between template restructuring and preservation of the porous architecture. After 1 hour, the metallic scaffold had begun to evolve, but its structure was not sufficiently stabilized to produce a robust graphene network after metal removal. After 3 hours, the template displayed improved continuity and stronger interconnections while retaining its porosity. This allowed the graphene structure to remain freestanding after etching. The comparison demonstrated that graphene quality alone does not determine the final stability. The geometry, connectivity, and thermal evolution of the metallic scaffold are equally important.
4. Removing the metallic template without polymer support is an important part of your fabrication process. What practical challenges did you encounter during this step, and how did you address them?
The main challenge was preserving the integrity of the ultralight graphene network during removal of the metallic template. Without a polymer support, the foam is highly vulnerable to mechanical handling, local defects, liquid flow, and capillary forces during washing and drying. Even small stresses can cause deformation or collapse. We addressed this challenge by improving the stability and interconnectivity of the Ni–Cu scaffold through controlled pre-annealing and by using gentle etching, washing, and transfer procedures. Minimizing manipulation was also essential. Avoiding polymer support simplified the process and reduced the risk of organic contamination, which is particularly important for applications involving charge transport, electrocatalysis, or surface-sensitive processes.
5. Your study discusses the potential of these graphene foams for electrocatalytic and photoelectrochemical applications. What would you consider the most important next step toward evaluating their performance in practical devices?
The most important next step is to integrate the graphene foams into functional electrochemical or photoelectrochemical devices and evaluate their performance under realistic operating conditions. This requires systematic measurements of electrical conductivity, charge-transfer resistance, electrochemically active surface area, catalytic activity, and long-term stability. We are particularly interested in using the foams as high-surface-area conductive scaffolds or three-dimensional current collectors for active materials such as transition-metal oxides, catalysts, or semiconductor photoelectrodes. Comparing these hybrid structures with conventional planar electrodes would help determine whether the interconnected graphene architecture provides measurable advantages in mass transport, charge collection, catalyst utilization, and device durability.
6. Looking back on the submission and publication of this paper, were there any aspects of choosing Nanomaterials, editorial communication, peer review, or the publication process that particularly stood out to you?
Nanomaterials was an appropriate choice because its scope reflects the interdisciplinary nature of our study, which combines electrochemical deposition, nanostructure engineering, graphene growth, and advanced structural characterization. The journal also reaches researchers working on both the fundamental properties and technological applications of nanomaterials. We appreciated the efficient editorial communication and the constructive comments received during peer review. The reviewers’ observations helped us clarify the experimental methodology, strengthen the interpretation of the results, and better explain the relationship between template evolution and graphene stability. Overall, the publication process was very well organized and helped us present the study in a clearer and more accessible form.