The series of seminars "Breakthroughs in Materials Science", organized by the Department of Materials Science of the University of Milano - Bicocca, brings together lectures by internationally renowned scientists, whose recent studies have promoted a profound evolution in the field of Materials Science. Presented with an informative nature, the seminars are aimed at researchers, students, and a wide audience of people interested in scientific topics. In addition to in-person participation, the streaming connection will be made available.

The following seminars are planned for 2025:

• April 7: Hiroshi Amano - Role of New Semiconductor Materials in Realizing Net Zero Carbon and Smart Society
• May 16: Georg Kresse - Machine learning and beyond DFT methods: quantitative materials modeling at your fingertips
• June 16: Omar Yaghi - Reticular Chemistry, Climate, AI CANCELED
• June 18: Stefan Kaskel - Responsive Porous Frameworks: Serendipity or Rational Design?
• September 24: Silvia Picozzi - Spins and electric dipoles: modelling and microscopic understanding
• December 2: Bernard Feringa - Smart Materials, from molecular switches to motors

The development of earth-abundant, non-precious catalysts is essential to the deployment of proton exchange membrane fuel cells and electrolyzers, which are essential components for decarbonizing the production and utilization of chemicals and fuels, including hydrogen and ammonia. Among the electrocatalysts for such applications, transition metal nitrides have emerged as promising and cost-effective materials. However, metal nitrides are affected by dissolution in acid resulting in material degradation, hindering their use in applications. In this study, by combining experimental characterizations and DFT calculations we elucidate the fundamental properties of transition metal nitrides governing their stability in acid and provide a key mechanistic understanding for metal nitrides dissolution and resulting ammonia formation. More importantly, these results provide guiding principles for designing and optimizing novel nitride chemistries for clean energy applications.

Jiayu Peng, Juan J. Giner-Sanz, Livia Giordano, William P. Mounfield III, Graham M. Leverick, Yang Yu, Yuriy Román-Leshkov, Yang Shao-Horn, Design principles for transition metal nitride stability and ammonia generation in acid, JOULE 7, 150-157 (2023).

Natural and anthropogenic gas radionuclides such as radon, xenon, hydrogen and krypton isotopes must
be monitored to be managed as pathogenic agents, radioactive diagnostic agents or nuclear activity indicators. State-of-the-art detectors based on liquid scintillators suffer from laborious preparation and
limited solubility for gases, which affect the accuracy of the measurements. The actual challenge is to find
solid scintillating materials simultaneously capable of concentrating radioactive gases and efficiently producing visible light revealed with high sensitivity. The high porosity, combined with the use of scintillating
building blocks in metal–organic frameworks (MOFs), offers the possibility to satisfy these requisites. We
demonstrate the capability of a hafnium-based MOF incorporating dicarboxy-9,10-diphenylanthracene as a scintillating conjugated ligand to detect gas radionuclides. Metal–organic frameworks show fast scintillation, a fluorescence yield of ∼40%, and accessible porosity suitable for hosting noble gas atoms and ions. Adsorption and detection of ⁸⁵Kr, ²²²Rn and ³H radionuclides are explored through a newly developed device that is based on a time coincidence technique. Metal–organic framework crystalline powder demonstrated an improved sensitivity, showing a linear response down to a radioactivity value below 1 kBq m⁻³ for ⁸⁵Kr, which outperforms commercial devices. These results support the possible use of scintillating porous MOFs to fabricate sensitive detectors of natural and anthropogenic radionuclides.

Matteo Orfano, Jacopo Perego, Francesca Cova, Charl X. Bezuidenhout, Sergio Piva, Christophe Dujardin, Benoit Sabot, Sylvie Pierre, Pavlo Mai, Christophe Daniel, Silvia Bracco, Anna Vedda, Angiolina Comotti, Angelo Monguzzi, Efficient radioactive gas detection by scintillating porous metal–organic frameworks, NATURE PHOTONICS 17, 672–678 (2023). 

In the last 20 years, direct alcohol fuel cells (DAFCs) have been the subject of tremendous research efforts
for the potential application as on-demand power sources. Two leading technologies respectively based
on proton exchange membranes (PEMs) and anion exchange membranes (AEMs) have emerged: the first
one operating in an acidic environment and conducting protons; the second one operating in alkaline electrolytes and conducting hydroxyl ions. In this review, we present an analysis of the state-of-the-art acidic and
alkaline DAFCs fed with methanol and ethanol with the purpose to support a comparative analysis of acidic
and alkaline systems, which is missing in the current literature. A special focus is placed on the effect of the
reaction stoichiometry in acidic and alkaline systems. Particularly, we point out that, in alkaline systems,
OH− participates stoichiometrically to reactions, and that alcohol oxidation products are anions. This aspect
must be considered when designing the fuel and when making an energy evaluation from a whole system
perspective.

Enrico Berretti, Luigi Osmieri, Vincenzo Baglio, Hamish A. Miller, Jonathan Filippi, Francesco Vizza, Monica Santamaria, Stefania Specchia, Carlo Santoro, Alessandro Lavacchi, Direct alcohol fuel cells: a comparative review of acidic and alkaline systems, ELECTROCHEM. ENERGY REV. 6, 30 (2023).

Due to their superior mechanical properties, 2D materials have gained interest as active layers in flexible devices co-integrating electronic, photonic, and straintronic functions altogether. To this end, 2D bendable membranes compatible with the technological process standards and endowed with large-scale uniformity are highly desired. Here, it is reported on the realization of bendable membranes based on silicene layers (the 2D form of silicon) by means of a process in which the layers are fully detached from the native substrate and transferred onto arbitrary flexible substrates. The application of macroscopic mechanical deformations induces a strain-responsive behavior in the Raman spectrum of silicene. It is also shown that the membranes under elastic tension relaxation are prone to form microscale wrinkles displaying a local generation of strain in the silicene layer consistent with that observed under macroscopic mechanical deformation. Optothermal Raman spectroscopy measurements reveal a curvature-dependent heat dispersion in silicene wrinkles. Finally, as compelling evidence of the technological potential of the silicene membranes, it is demonstrated that they can be readily introduced into a lithographic process flow resulting in the definition of flexible device-ready architectures, a piezoresistor, and thus paving the way to a viable advance in a fully silicon-compatible technology framework.

Christian Martella, Chiara Massetti, Daya Sagar Dhungana, Emiliano Bonera, Carlo Grazianetti, Alessandro Molle, Bendable silicene membranes, ADVANCED MATERIALS 35, 2211419 (2023).

Electronic structure calculations represent an essential complement of experiments to characterize single-atom catalysts (SACs), consisting of isolated metal atoms stabilized on a support, but also to predict new catalysts. However, simulating SACs with quantum chemistry approaches is not as simple as often assumed. In this work, the essential factors that characterize a reliable simulation of SACs activity are examined. The Perspective focuses on the importance of precise atomistic characterization of the active site, since even small changes in the metal atom's surroundings can result in large changes in reactivity. The dynamical behavior and stability of SACs under working conditions, as well as the importance of adopting appropriate methods to solve the Schrödinger equation for a quantitative evaluation of reaction energies are addressed.

The Perspective also focuses on the relevance of the model adopted. For electrocatalysis this must include the effects of the solvent, the presence of electrolytes, the pH, and the external potential. Finally, it is discussed how the similarities between SACs and coordination compounds may result in reaction intermediates that usually are not observed on metal electrodes. When these aspects are not adequately considered, the predictive power of electronic structure calculations is quite limited.

Giovanni Di Liberto, Gianfranco Pacchioni, Modeling single-atom catalysis, ADVANCED MATERIALS 35, 2307150 (2023).

Scientific Diretctor: Prof. N. Manfredi
Location: Room 2036b, 2nd Floor, U5 Building

The ORACLE laboratory, dedicated to the synthesis of organic molecules, is located on the second floor of Building U5, Room 2036b. Here, innovative photochromic molecular materials for next-generation photovoltaic cells and conductive organic materials intended for biomedical sensors functionalized for cell growth are designed and analysed. In parallel to these activities, organic molecules intended for the photoproduction of solar fuels, are being developed by exploiting renewable and abundant sources such as sunlight, water, and carbon dioxide, and by exploiting pollutants as sacrificial reagents for photo(electro)catalytic hydrogen generation. ORACLE collaborates closely with the MIB-SOLAR laboratory (building U5, ground floor), where solar devices based on the synthesized materials are fabricated and analysed, and with laboratories specializing in chemical characterization (NMR, absorption and emission spectroscopy, advanced microscopy, mass spectrometry, HPLC, etc.). ORACLE is fully equipped for the synthesis of organic molecules of different types, which are then analysed by various characterization techniques.

The development of conductive and photoactive organic materials is essential for advancing sustainable energy technologies. In solar cells, these materials enable the creation of flexible, lightweight, and adaptable devices, ideal for integration with portable electronics and IoT technologies, allowing autonomous power supply for sensors and smart devices. In biosensors, they provide high sensitivity and biocompatibility for advanced medical monitoring. In photocatalysis, they facilitate the production of solar fuels, such as hydrogen and methane, using renewable sources like sunlight, water, and CO₂. Their synthesis and characterization open new opportunities for clean energy technologies, supporting the transition to a more sustainable future and reducing dependence on fossil fuels.

The main research activities carried out in the group concern the design of molecular materials capable of expressing conductive properties. The interest is mainly in the development of molecular materials trying to keep synthetic procedures simple and aiming in the direction of reducing the environmental impact of synthesis by reducing the use of particularly polluting starting materials (solvents and reagents) and reducing synthetic steps. The molecular approach allows high control over the purity and properties of the materials themselves. Moreover, by going to modify the functionalization of these molecular materials it is possible to change their characteristics and allow different surface interactions with organic or aqueous environments allowing their use in different devices: solid-state solar cells or biosensors.

Organic molecular materials capable of interacting with light are being developed in the field of photoactive materials. The class of photoactive materials mainly developed are photochromic dyes that are used for special dye-sensitized solar cells to be applied as smart-windows or smart-glasses. In this application, the choice of colour in the two forms is particularly delicate and imposes a major study at the molecular design level. These materials can also act as photosensitizers in the photo(electro)catalytic processes for producing solar fuels from wastewater.

Prof. Norberto Manfredi

ORACLE Lab – U5 Building, 2nd Floor, Room 2036b
MIBSOLAR Lab – U5 Building, Ground Floor, Room T057-T067

• Fully equipped organic synthesis and characterization laboratories. 
• Clean-room labs (MIB-SOLAR and FLEXILAB) for preparation and characterization of photocatalytic and photelectrochemical devices for artificial photosynthesis and photovoltaics.

The Department has signed into a series of agreements for the creation of joint laboratories with other foreign institutions or companies, in which researchers from the Department and foreign researchers or R&D employees share, in addition to their skills, the own research structures displaying new characteristics compared to the two proposing institutes.

In this context, the Department established the joint QUCAT Laboratory (Quantum Nanostructure Photo-Catalysis) with the South China Normal University (SCNU) of Guanzhou (China) for the study of advanced materials, through the departmental laboratory for fabrication and study of semiconductor quantum nanostructures (EpiLab).

The University's commitment to research and innovation, particularly in sectors such as biotechnology and development of new materials, takes a further step forward by interfacing directly with the business world to promote greater integration of industrial and university towards high-quality results. The framework agreement between the university and the leading international company in the development and production of cosmetic products, Intercos S.p.A (https://www.intercos.com/), starts a long-lasting collaboration, not limited to a single project but open to possible developments also in teaching. It is a forward-looking investment, aiming at carrying out a project that has no precedent in this sector at an academic and industrial level. The concentration of human and technological resources, made possible by a shared environment and the availability of cutting-edge tools, offers the possibility to achieve excellent scientific results at national and international level. The general guidelines for the development of the activities, the analysis and the definition of the operational projects are entrusted to a Technical Scientific Committee which includes, on an equal basis, representatives of the University and Intercos.