Periodic Reporting for period 4 - 2D-PnictoChem (Chemistry and Interface Control of Novel 2D-Pnictogen Nanomaterials)
Reporting period: 2023-05-01 to 2024-04-30
Project purposes was to explore the Chemistry of a novel class of graphene-like 2D layered elemental materials of group 15, the pnictogens: P, As, Sb & Bi. In recent years, these materials have gained popularity in Materials Science due to their ability to outperform/complement graphene properties. Their strongly layer-dependent unique properties range from semiconducting to metallic, including high carrier mobilities, tunable bandgaps, strong spin-orbit coupling or transparency. 2D-PnictoChem is a pioneering project in the field of pnictogen chemistry, a relatively unexplored area in the field of chemistry. We have advanced in the 2D-pnictogen synthesis and assembly in complex hybrid heterostructures using a cross-disciplinary approach combining Inorganic- and Organic Chemistry with Solid-state Physics, including:
1) Synthetizing and exfoliating high-quality ultra-thin layer pnictogens using innovative colloidal bottom-up approaches.
2) Achieving chemical functionalization through non-covalent and covalent approaches to customize properties, understand reactivity patterns, and enable controlled doping avenues.
3) Developing hybrid architectures through a precise chemical control of the interface to promote access to novel heterostructures.
4) Exploring novel application concepts achieving outstanding performances.
2D-PnictoChem has addressed relevant challenges in batteries, electronic devices, and catalysis. The project led to significant advances in 2D materials fundamental science, with more than 50 papers, including reviews and covers, and significant technological transfer activities, with several patents, in novel material synthesis and energy storage applications and conversion. One of these patents led to the creation of a spin-off, Matteco, with 30 employees, focusing on marketing innovative catalysts for green hydrogen production globally in just two years.
1) Synthetizing and exfoliating high-quality ultra-thin layer pnictogens using innovative colloidal bottom-up approaches.
2) Achieving chemical functionalization through non-covalent and covalent approaches to customize properties, understand reactivity patterns, and enable controlled doping avenues.
3) Developing hybrid architectures through a precise chemical control of the interface to promote access to novel heterostructures.
4) Exploring novel application concepts achieving outstanding performances.
2D-PnictoChem has addressed relevant challenges in batteries, electronic devices, and catalysis. The project led to significant advances in 2D materials fundamental science, with more than 50 papers, including reviews and covers, and significant technological transfer activities, with several patents, in novel material synthesis and energy storage applications and conversion. One of these patents led to the creation of a spin-off, Matteco, with 30 employees, focusing on marketing innovative catalysts for green hydrogen production globally in just two years.
The 2D-PnictoChem project has been focused on three primary topics:
i) 2D-Pnictogens nanomaterials (phosphorene, antimonene, and bismuthene);
ii) Hybrid architectures (among others, the combination of 2D-Pnictogens with other nanomaterials: i.e. graphene or layered hydroxides);
iii) Devices and applications. Regarding the first one, new 2D materials based on black phosphorus, antimony, bismuth, layered double hydroxides (LDHs), and graphene have been obtained using different approaches (i.e liquid phase exfoliation, micromechanical exfoliation, and chemical synthesis). A significant achievement has been the bottom-up large-scale colloidal synthesis of antimonene hexagons (Sb-H) (publication #34) and bismuthene hexagons (Bi-H) (publication #54). Indeed, our optimized synthesis yields Sb-H with lateral dimensions up to 6 microns and thicknesses 4–20 nm, comparable to chemical vapor deposition or MBE. High-quality Sb-H with low surface oxidation is demonstrated through mechanical and transport experiments. This achievement offers an alternative route for producing high-quality antimonene with higher yields than previously reported. We have deciphered the oxidation behavior in antimonene, controlling the formation of antimonene oxide/antimonene heterostructures with semiconductor/semimetal character. Bismuthene and Sb-H, obtained through colloidal synthesis, have been found to have highly interesting results in high-quality, hexagonal-shaped particles (Bi-H) with lateral size of ~ 1 µm and thickness between 8 and 20 nm.
The innovative synthesis has been protected by patent in 2021. These results open the door for the development of heavy pnictogens-based technologies since they allow for the first time the large-scale synthesis of high-quality nanosheets for applications in electronics and beyond.
Regarding the second theme, the first bulk reductive covalent functionalization of black phosphorus achieved the highest functionalization degrees and revealed that the P-P bond breaks when P is functionalized.
We have linked Raman spectra changes of bP to its functionalization using solid-state NMR, enabling the quantification of covalent functionalization of black phosphorus using Raman spectroscopy. To produce hybrid heterostructures, we have developed an enormous work of synthesis of other functionalized 2D materials. In fact, we developed the first covalent functionalization of NiFe LDHs, and the first bottom-up synthesis of ultrathin layered hexagonal magnets based on α-CoII hydroxychlorides. We also discovered and patented a scalable synthetic approach for preparing NiFe-LDHs, a crucial oxygen evolution reaction electrocatalyst, which paved the way for Matteco, a spin-off company. We successfully carried out the first multifunctionalization of high-quality graphene with 3 protected different functional groups, preparing hybrid heterostructures assembled through controlled covalent and interface interactions (and not limited to van der Waals forces). Concerning the third topic (devices and applications), the first use of 2D-Pnictogens in organic catalysis, specifically liquid phase exfoliation of phosphorene and antimonene in ionic liquids, has led to excellent catalysts in the alkylation of soft nucleophiles with esters. In electronic devices, the first organic field-effect transistor with functionalized black phosphorus was successfully prepared using a non-covalent pathway and ad-hoc synthesized perylenes.
The study on antimonene oxidation behavior in nanomedicine revealed its effectiveness in influencing cell line cytotoxicity. Top-down (nanosheets and nanoparticles) and bottom-up (Sb-H) synthetic procedures led to diverse oxidation behavior, with hexagonal antimonene being faster oxidized, making it suitable for efficient cancer chemotherapy (publication #66). The study also explores the development and applications of carbon nanomaterials, specifically carbon nano onions (CNOs). It demonstrates CNOs' ability to intercalate alkali metals, paving the way for their potential use in ion batteries (Publication #39). Additionally, the study addresses aggregation and low water solubility issues (Publication #62).
i) 2D-Pnictogens nanomaterials (phosphorene, antimonene, and bismuthene);
ii) Hybrid architectures (among others, the combination of 2D-Pnictogens with other nanomaterials: i.e. graphene or layered hydroxides);
iii) Devices and applications. Regarding the first one, new 2D materials based on black phosphorus, antimony, bismuth, layered double hydroxides (LDHs), and graphene have been obtained using different approaches (i.e liquid phase exfoliation, micromechanical exfoliation, and chemical synthesis). A significant achievement has been the bottom-up large-scale colloidal synthesis of antimonene hexagons (Sb-H) (publication #34) and bismuthene hexagons (Bi-H) (publication #54). Indeed, our optimized synthesis yields Sb-H with lateral dimensions up to 6 microns and thicknesses 4–20 nm, comparable to chemical vapor deposition or MBE. High-quality Sb-H with low surface oxidation is demonstrated through mechanical and transport experiments. This achievement offers an alternative route for producing high-quality antimonene with higher yields than previously reported. We have deciphered the oxidation behavior in antimonene, controlling the formation of antimonene oxide/antimonene heterostructures with semiconductor/semimetal character. Bismuthene and Sb-H, obtained through colloidal synthesis, have been found to have highly interesting results in high-quality, hexagonal-shaped particles (Bi-H) with lateral size of ~ 1 µm and thickness between 8 and 20 nm.
The innovative synthesis has been protected by patent in 2021. These results open the door for the development of heavy pnictogens-based technologies since they allow for the first time the large-scale synthesis of high-quality nanosheets for applications in electronics and beyond.
Regarding the second theme, the first bulk reductive covalent functionalization of black phosphorus achieved the highest functionalization degrees and revealed that the P-P bond breaks when P is functionalized.
We have linked Raman spectra changes of bP to its functionalization using solid-state NMR, enabling the quantification of covalent functionalization of black phosphorus using Raman spectroscopy. To produce hybrid heterostructures, we have developed an enormous work of synthesis of other functionalized 2D materials. In fact, we developed the first covalent functionalization of NiFe LDHs, and the first bottom-up synthesis of ultrathin layered hexagonal magnets based on α-CoII hydroxychlorides. We also discovered and patented a scalable synthetic approach for preparing NiFe-LDHs, a crucial oxygen evolution reaction electrocatalyst, which paved the way for Matteco, a spin-off company. We successfully carried out the first multifunctionalization of high-quality graphene with 3 protected different functional groups, preparing hybrid heterostructures assembled through controlled covalent and interface interactions (and not limited to van der Waals forces). Concerning the third topic (devices and applications), the first use of 2D-Pnictogens in organic catalysis, specifically liquid phase exfoliation of phosphorene and antimonene in ionic liquids, has led to excellent catalysts in the alkylation of soft nucleophiles with esters. In electronic devices, the first organic field-effect transistor with functionalized black phosphorus was successfully prepared using a non-covalent pathway and ad-hoc synthesized perylenes.
The study on antimonene oxidation behavior in nanomedicine revealed its effectiveness in influencing cell line cytotoxicity. Top-down (nanosheets and nanoparticles) and bottom-up (Sb-H) synthetic procedures led to diverse oxidation behavior, with hexagonal antimonene being faster oxidized, making it suitable for efficient cancer chemotherapy (publication #66). The study also explores the development and applications of carbon nanomaterials, specifically carbon nano onions (CNOs). It demonstrates CNOs' ability to intercalate alkali metals, paving the way for their potential use in ion batteries (Publication #39). Additionally, the study addresses aggregation and low water solubility issues (Publication #62).
Most of the results obtained in 2D-PnictoChem represent great advances beyond the state-of-the-art and contributed to lay strong fundaments on pnictogens materials chemistry. Just to mention a few, we can consider i) large-scale colloidal synthesis of few-layer 2D-Sb with electronic quality; ii) discovery of the oxidation behavior in antimonene and characterization of the bandgap; iii) first bulk covalent functionalization of phosphorene and the quantification of the functionalization degree; iv) first organic field effect transistor using a 2D-pnictogen; v) first use of 2D-Pnictogens in organic catalysis of industrial relevance; vi) Colloidal synthesis of bismuthene with plasmonic quality, and surface functionalization (Bi-H).
Moreover, regarding energy storage and conversion, we obtained patents based on 2D materials for green H2 production (EP21382113), scalable colloidal synthesis of bismuthene (P202130722), and metal collectors-free Li-ion batteries (PTC/ES2022/070779).
In addition, we are currently investigating the use of 2D-Bi in sodium-ion batteries, the photonic and electronic properties of Sb-H, the biomedical applications of 2D-Pnictogens as well as the synthesis of bismuth-based heterostructures.
Moreover, regarding energy storage and conversion, we obtained patents based on 2D materials for green H2 production (EP21382113), scalable colloidal synthesis of bismuthene (P202130722), and metal collectors-free Li-ion batteries (PTC/ES2022/070779).
In addition, we are currently investigating the use of 2D-Bi in sodium-ion batteries, the photonic and electronic properties of Sb-H, the biomedical applications of 2D-Pnictogens as well as the synthesis of bismuth-based heterostructures.