Research

Energy Harvesting and H2 Production from Water Splitting 

Ref.: M. Chiesa, M.C. Paganini, S. Livraghi.

The research focuses on the synthesis and characterization of innovative semiconductor oxide-based photocatalysts and hybrid systems involving the use of biocatalysts (hydrogenases) for hydrogen production (water photo-splitting).


RECENT PUBLICATIONS ON THE TOPIC:

Paganini MC, Livraghi S. et al., Chemical Science, 2020, DOI: 10.1039/d0sc02876b

Paganini MC, et al., J. of Cleaner Production, 2020, DOI: 10.1016/j.jclepro.2019.119762

Livraghi S. et al.  J. Mag. Res. 2020 DOI: doi.org/10.1007/s00723-020-01226-w

Structure and Reactivity of Catalytic Active Sites in Heterogeneous Homogeneous and Enzyme Catalysts 

Ref.: M. Chiesa, E. Salvadori.

Chemical reactions are controlled by two fundamental parameters, energy and angular momentum – the spin – of reactants. Spin-states and spin density distribution play a crucial role in determining the structure and reactivity of heterogeneous, homogeneous and enzymatic catalysts. The focus of this research is on understanding, through an experimental approach, how the spin properties impact on chemical reactivity and catalysis.

Recently, we have become particularly interested in determining the long-range spatial distribution of spin-bearing species in inorganic and bioinorganic systems and in monitoring the origin and fate of metastable species formed upon photoexcitation.



RECENT PUBLICATIONS ON THE TOPIC:

Chiesa M., Salvadori E., et al. Angewandte Chemie, 2019, DOI: 10.1002/anie.201906488

Chiesa M., Salvadori E., et al.Nature Communications, 2021, DOI: 10.1038/s41467-021-24935-7

Chiesa M., Salvadori E., et al., JACS, 2022, DOI: 10.1021/jacs.2c06037

Salvadori E., Chiesa M., et al., Angewandte Chemie, 2022, DOI: 10.1002/anie.202210640

Salvadori E., Chiesa M. et al., Angewandte Chemie, 2023, DOI: 10.1002/anie.202313540

Salvadori E. Chiesa M., et al., Acc. Chem. Res. 2023, DOI: 10.1021/acs.accounts.2c00606 


Solar Chemistry & Photocatalysis. Environmental Applications 

Ref.: M. C. Paganini, S. Livraghi.

Chemical reactions are controlled by two fundamental parameters, energy and spin of reactants. Spin plays a crucial role in determining the structure and reactivity of heterogeneous, homogeneous and enzymatic catalysts. The focus of this research is on the experimental determination of spin states and spin densities and their impact on chemical reactivity and catalysis. 


RECENT PUBLICATIONS ON THE TOPIC:

Paganini MC et al., Chemosphere, 2022, DOI:10.1016/j.chemosphere.2022.135017

Paganini MC et al., J. of Photochem. Photobio. A: Chemistry, 2022, DOI: 10.1016/j.jphotochem.2022.113775

Paganini MC et al., J. of Environmental Chemical Engineering, 2019, DOI: 10.1016/j.jece.2019.103475

Livraghi S. et al., J. of Environmental Chemical Engineering, 2023, DOI: 10.1016/j.jece.2023.109451

Livraghi S. et al.,  Adv. Mater. Interfaces, 2022 DOI: 10.1002/admi.202100532


Spinning Around in Transition-Metal Chemistry 

Ref.: M. Chiesa, E. Salvadori.

The great diversity and richness of transition metal (TM) chemistry, such as the features of an open d-shell, opened a way to numerous areas of scientific research and technological applications including the realization of future devices operating on quantum states. This collaborative project deals with different aspects related to the control of spin-dependent electronic properties. EPR spectroscopy, with emphasis on advanced pulse EPR techniques are used to probe the nature of spin states and electron spin relaxation properties, which are key for the implementation of specific quantum systems for emerging quantum and spintronic devices. 


RECENT PUBLICATIONS ON THE TOPIC:

Chiesa M, Salvadori E., et al.Chemical Science, 2022, DOI: 10.1039/D2SC04969D

Salvadori E., Chiesa M., et al., Chemical Science, 2022, DOI: 10.1039/D2SC03712B

Chiesa M. Salvadori E., et al., JACS Au, 2023, DOI: 10.1021/jacsau.3c00121


Charge Separated States and Excess Electrons in Reducible Oxides

Ref.: M.Chiesa, M.C. Paganini, S. Livraghi

Defect states, surface morphology and surface composition have an important role in determining the reactivity of oxide materials (TiO2, ZrO2, CeO2, ...) as well as the possibility of engineering defects in order to modify the oxide band gap and/or the light absorption properties. Specific synthetic methods are used to produce and characterize oxide nanoparticles with different morphologies and composition. EPR techniques are employed in the characterization of these materials with the aim of achieving an atomic scale understanding of their properties. Particular attention is devoted to the presence of point defects, to the formation of mixed systems and to the photochemical phenomena of charge separation under various types of illumination. In this latter case EPR is extremely useful since it allows the direct observation of photogenerated electrons and holes or the products of their surface reactivity.

Characterization and Reactivity of Surface-Localized Inorganic Radicals and Radical Ions 

Ref.: M.Chiesa, M.C. Paganini, S. Livraghi

The formation of surface inorganic radicals and radical ions formed at the interface between a solid and a gas phase is relevant to a number of fields, including electrochemistry, heterogeneous catalysis, photocatalysis, and corrosion phenomena. Identification and characterization of surface radicals are essentially conducted using EPR techniques which provide, on the basis of g tensor, hyperfine, and superhyperfine tensors, a detailed understanding of the radical composition and structure and, in some cases, the nature of the surface adsorption sites