In addition to a great swelling ability, layered silicates also allow the functionalization of their interlayer region to form various robust green materials that are used as CO₂ adsorbents, drug carriers, or catalysts. Here, the unique magadiite structure, which has resisted elucidation despite many attempts and applications the material offers, is finally described. A material-specific strategy allowed the use of 3D electron diffraction which led to the success of deciphering the atomic structure. In order to enable an ab initio structure solution of the electron beam sensitive material, a sodium-free dehydrated form of magadiite was synthetically isolated, and, from that, it was subsequently possible to derive a structure model for the sodium form of magadiite, later successfully refined against powder X-ray diffraction data. Furthermore, a geometry optimization and simulations of spectroscopic data with DFT methods confirm the obtained crystal structure of sodium magadiite. These results finally prompted a detailed description of the layers and of the chemically active interlayer region and provide a huge impact toward the design of new and more efficient materials based on functionalized magadiite and related structures.

The synthesis of [Al]-magadiite (Si/Al = 15) was monitored during preparation and crystallization by the Aluminium-Induced Crystallization method developed previously (G. B. Superti, E. C. Oliveira, H. O. Pastore, G. Gatti and L. Marchese, Chem. Mater., 2007, 19, 4300–4315.). For monitoring purposes samples were collected at 0, 12 and 24 h and after aluminium introduction at 0, 6 and 12 h of hydrothermal treatment. A systematic study of the physicochemical and thermal properties of the products obtained at each step in [Al]-magadiite synthesis was performed by combining different experimental techniques [infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA) and solid-state magic-angle spinning nuclear magnetic resonance (MAS-NMR)]. ²⁷Al MAS NMR confirmed the insertion of Al ions into the magadiite framework in tetrahedral positions. The results obtained showed that the hydrothermal treatment before aluminium insertion served essentially for the creation of magadiite seeds. Thus, induced crystallization by introduction of magadiite seeds directly in the synthesis gel showed that the synthesis duration could be reduced and variable Si/Al ratios showed that the increase in aluminium concentration affects the crystallinity of the material and allows us to obtain [Al]-magadiite with different Si/Al ratios in a single step. Different Al_td nonequivalent sites were detected by 3QMAS-NMR experiment. X-Ray photoelectron spectroscopy (XPS) allowed designing the [Al]-magadiite structure as a pure silicon magadiite core with a thin layer of aluminosilicate deposited on top of it.

Energy storage will be a primordial actor of the ecological transition initiated in the energy and transport sectors. As such, innovative approaches to design high-performance electrode materials are crucial for the development of the next generation of batteries. Herein, a novel dual redox-active and porous polyimide network (MTA-MPT), based on mellitic trianhydride (MTA) and 3,7-diamino-N-methylphenothiazine (MPT) monomers, is proposed for applications in both high energy density lithium batteries and symmetric all-organic batteries. The MTA-MPT porous polyimide was synthesized using a novel environmentally-friendly hydrothermal polymerization method. Rooted in its dual redox proprieties, the MTA-MPT porous polyimide exhibits a high theoretical capacity making it a very attractive cathode material for high energy density battery applications. The cycling performance of this novel electrode material was assessed in both high energy density lithium batteries and light-weight symmetric all-organic batteries, displaying excellent rate capability and long-term cycling stability.

Biogenic metal oxides (M_xO_y) feature structures as highly functional and unique as the organisms generating them. They have caught the attention of scientists for the development of novel materials by biomimicry. In order to understand how biogenic M_xO_y could inspire novel technologies, we have reviewed examples of all biogenic M_xO_y, as well as the current state of understanding of the interactions between the inorganic M_xO_y and the biological matter they originate from and are connected to. In this review, we first summarize the origins of the precursors that living nature converts into M_xO_y. From the point-of-view of our materials chemists, we present an overview of the biogenesis of silica, iron and manganese oxides, as the only reported biogenic M_xO_y to date. These M_xO_y are found across all five kingdoms (bacteria, protoctista, fungi, plants and animals). We discuss the key molecules involved in the biosynthesis of M_xO_y, the functionality of the M_xO_y structures, and the techniques by which the biogenic M_xO_y can be studied. We close by outlining the biomimetic approaches inspired by biogenic M_xO_y materials and their challenges, and we point at promising directions for future organic-inorganic materials and their synthesis.

Novel hybrid mesoporous and functionalized materials with controllable surface area and pore dimensions with functional basic sites (–NH₂) were synthesized from magadiite and [Al]-magadiite as layered silicate precursors. The variable pore structure and properties of these materials were investigated in these solids by using different CTA⁺/Na⁺ (CTA⁺ = cetyltrimethylammonium cation) molar ratios in the pre-modification step with aminopropyltriethoxysilane (APTS) and tetraethoxysilane (TEOS). Characterizations were carried out by different techniques to probe the effects of the amounts of interlayer surfactant in the synthesis of the pillared and/or grafted materials. The crystalline structures of magadiite and [Al]-magadiite layers were maintained as evidenced by FT-IR and SAED and contain pillars and aminopropyl groups in the interlayer space. The hybrid solids were compared to the pillared forms (H. M. Moura, F. A. Bonk and H. O. Pastore, Eur. J. Mineral., 2012, 24, 903) and to the aminopropyl-grafted forms and presented the properties of both solids with the CO₂ adsorption capability improved considerably.