Giorgio Contini

Electrochemical reduction of carbon dioxide to methanol represents one of the most demanding transformations in CO ₂ conversion, requiring the management of a six-electron, six-proton sequence while suppressing competing pathways toward carbon monoxide, formate, and hydrogen evolution. Among molecular electrocatalysts, cobalt phthalocyanine (CoPc) has emerged as a unique molecular platform capable of extending CO ₂ reduction beyond CO through a domino-like cascade of protoncoupled electron transfer steps. Its square-planar Co-N ₄ coordination environment provides metalcentered redox couples that enables CO ₂ activation at the Co(I) state and stabilizes key intermediates within a narrow adsorption-energy window compatible with further hydrogenation. This review examines the fundamental and applied aspects of CoPc-mediated electrochemical CO ₂ and CO reduction to methanol. The effects of ring substitution, axial ligation, and support-induced distortions on redox potentials, orbital interactions, and intermediate binding energetics were analyzed. Particular attention was devoted to solvation-coupled proton-coupled electron transfer, cation effects, and electric double-layer structure, which collectively governed CO retention and sequential hydrogenation toward CH ₃ OH. Immobilization strategies on carbon nanotubes and related supports were discussed in relation to molecular dispersion, electronic coupling, and stability under flow-cell operation. Finally, scalability and sustainability are assessed through life-cycle considerations and green-chemistry metrics applied to phthalocyanine synthesis and device integration. Despite these advances, the field remains limited by catalyst deactivation, incomplete comparability among electrochemical setups and the frequent lack of standardized metrics for methanol quantification under device-relevant conditions. By connecting molecular design interfacial microenvironment, reactor architecture and sustainable catalyst synthesis, this review identifies the key directions required to move CoPc-based systems from promising molecular models toward technologically credible CO ₂ -to-methanol electrolysis.

Two-dimensional nanomaterials are at the forefront of next-generation technologies, with applications spanning quantum computing, catalysis, and sensing. Among these, on-surface synthesized two-dimensional conjugated polymers (2DCPs) with Kagomé lattice symmetry have recently emerged as promising candidates, thanks to their ability to form large, ordered domains and their unique electronic structures featuring both flat bands and Dirac cones. In this work, we report the integration of atomically thin, surface-confined 2DCPs into field-effect transistors (FETs), marking a step toward their use in functional devices. The fabricated FETs exhibit ohmic transport behavior with Pt contacts and reveal ambipolar graphene-like field-induced conductivity modulation, directly linked to the Dirac cone in the electronic band structure. These findings are supported by ab initio density functional theory (DFT) calculations and finite element simulations of the drift-diffusion equation, confirming the transport characteristics. Our results highlight the potential of 2DCPs with Kagomé lattice symmetry as highly tunable, organic systems for future applications in nanoelectronics and high-performance sensing.

We report a sustainable and cost‐effective synthesis of cobalt phthalocyanine (CoPc) using low‐impact solvents and a streamlined purification procedure, achieving an 85% yield with limited waste generation, as indicated by an environmental factor (E‐factor) of 18.6. This route provides an eco‐friendly approach to producing a molecular electrocatalyst for reduction. The catalytic activity of the synthesized CoPc is validated by its integration into a gas diffusion electrode with carbon nanotube supports, exhibiting methanol production with a Faradaic efficiency up to 12%, matching the values reached with the conventionally synthesized counterparts. Notably, under high loading (micrometric crystallites of CoPc), ‐to‐CO conversion reached 65%, in fair alignment with literature benchmarks. Our work shows that green synthesis can yield high‐performance catalysts for electrochemical reduction (), enabling sustainable methanol production.

Two-dimensional nanomaterials are at the forefront of next-generation technologies, with applications spanning quantum computing, catalysis, and sensing. Among these, on-surface synthesized two-dimensional conjugated polymers (2DCPs) with kagomé lattice symmetry have recently emerged as promising candidates, thanks to their ability to form large, ordered domains and their unique electronic structures featuring both flat bands and Dirac cones. In this work, we report the integration of atomically-thin, surface-confined 2DCPs into field-effect transistors (FETs), marking a step toward their use in functional devices. The fabricated FETs exhibit ohmic transport behavior with Pt contacts and reveal ambipolar graphene-like field induced conductivity modulation, directly linked to the Dirac cone in the electronic band structure. These findings are supported by ab initio density functional theory (DFT) calculations and finite element simulations of the drift-diffusion equation, confirming the transport characteristics. Our results highlight the potential of 2DCPs with kagomé lattice symmetry as highly tunable, organic systems for future applications in nanoelectronics and high-performance sensing.

Ullmann coupling is a widely used reaction for the on-surface growth of low-dimensional carbon nanomaterials. The irreversible nature of this reaction prevents the "self-healing" of defects, and a detailed knowledge of its mechanism is therefore essential to enable the growth of extended ordered structures. However, the dynamics of the Ullmann polymerization remain largely unexplored, as coupling events occur on a timescale faster than conventional scanning probe microscopy imaging frequencies. Here, we reveal the dynamics of these surface events using high-speed variable-temperature scanning tunneling microscopy (STM) (10 frames per second). Performing the measurements at the onset reaction temperatures provides an unprecedented description of the evolution of organometallic (OM) and covalent surface species during the Ullmann polymerization of para-dibromobenzene on Cu(110). Our results demonstrate the existence of an intermediate OM phase with Cu adatoms that inhibits the polymerization. These observations now complete the picture of the pathways of on-surface Ullmann polymerization, which includes the complex interplay of the phenylene moieties and metal atoms. Our work demonstrates the unique capability of high-speed STM to capture the dynamics of molecular self-assembly and coupling.

The temporal evolution of the reactant concentrations as measured by XPS for different temperature profiles reveals that the debromination of organic molecules on Ag(111) is activated by Ag adatoms.

Two-dimensional conjugated polymers (2DCPs) are an emerging class of materials that exhibit properties similar to graphene yet do not have the limitation of zero bandgap. On-surface synthesis provides exceptional control on the polymerization reaction, allowing tailoring properties by choosing suitable monomers. Heteroatom-substituted triangulene 2DCPs constitute a playing ground for such a design and are predicted to exhibit graphene-like band structures with high charge mobility and characteristic Dirac cones in conduction or valence states. However, measuring these properties experimentally is challenging and requires long-range-ordered polymers, preferably with an epitaxial relationship with the substrate. Here, we investigate the electronic properties of a mesoscale-ordered carbonyl-bridged triphenylamine 2DCP (P²TANGO) and demonstrate the presence of a Dirac cone by combining angle-resolved photoemission spectroscopy (ARPES) with density functional theory (DFT) calculations. Moreover, we measure the absolute energy position of the Dirac cone with respect to the vacuum level. We show that the bridging functionality of the triangulene (ether vs carbonyl) does not significantly perturb the band structure but strongly affects the positioning of the bands with respect to the Au(111) states and allows control of the ionization energy of the polymer. Our results provide proof of the controllable electronic properties of 2DCPs and bring us closer to their use in practical applications.

Interleukin-6 (IL-6) plays a crucial role in autoimmunity and chronic inflammation. This study aims to develop a low-cost, simple-to-manufacture, and user-friendly label-free electrochemical point-of-care device for the rapid detection of IL-6 in patients with psoriasis. Precisely, a sandwich-based format immunosensor was developed using two primary antibodies (mAb-IL6 clone-5 and clone-7) and screen-printed electrodes modified with an inexpensive recycling electrochemical enhancing material, called biochar. mAb-IL6 clone-5 was used as a covalently immobilized capture bioreceptor on modified electrodes, and mAb-IL6 clone-7 was used to recognize the immunocomplex (Anti-IL6 clone-5 and IL-6) and form the sandwich. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were used to conduct electrochemical characterization of the layer-by-layer assembly of the immunosensor, while square wave voltammetry (SWV) was used to perform the sensing. The developed immunosensor demonstrated robust analytical performance in buffer solution, with a wide linear range (LR) by varying from 2 to 250 pg/mL, a good limit of detection (LOD) of 0.78 pg/mL and reproducibility (RSD<7%). In addition, a spectrophotometric ELISA kit was employed to validate the results obtained with the label-free device by analyzing twenty-five serum samples from control and patients affected by psoriasis. A strong correlation in terms of pg/mL concentration of IL-6 was found comparing the two methods, with the advantage for our label-free biosensor of an ease use and a quicker detection time. Based on IL-6 levels, the proposed immunosensor is a dependable, non-invasive screening device capable of predicting disease onset, progression, and treatment efficacy.

2D materials with high charge carrier mobility and tunable electronic band gaps have attracted intense research effort for their potential use as active components in nanoelectronics. 2D-conjugated polymers (2DCP) constitute a promising sub-class due to the fact that the electronic band structure can be manipulated by varying the molecular building blocks, while at the same time preserving the key features of 2D materials such as Dirac cones and high charge mobility. The major challenge for their use in technological applications is to fabricate mesoscale ordered 2DCP networks since current synthetic routes yield only small domains with a high density of defects. Here we demonstrate the synthesis of a mesoscale ordered 2DCP with semiconducting properties and Dirac cone structures via Ullmann coupling on Au(111). This material has been obtained by combining rigid azatriangulene precursors and a hot dosing approach which favours molecular diffusion and reduces the formation of voids in the network. These results open opportunities for the synthesis of 2DCP Dirac cone materials and their integration into devices.