Electronics, and nanoelectronics in particular, represent one of the most promising branches of technology. The search for novel and more efficient materials seems to be natural here. Thus far, silicon-based devices have been monopolizing this domain. Indeed, it is justified since it allows for significant miniaturization of electronic elements by their densification in integrated circuits. Nevertheless, silicon has some restrictions. Since this material is applied in the bulk form, the miniaturization limit seems to be already reached. Moreover, smaller silicon-based elements (mainly processors) need much more energy and generate significantly more heat than their larger counterparts. In our opinion, the future belongs to nanostructured materials where a proper structure is obtained by means of bottom-up nanotechnology. A great example of a material utilizing nanostructuring is mesoporous silica, which, due to its outstanding properties, can find numerous applications in electronic devices. This focused review is devoted to the application of porous silica-based materials in electronics. We guide the reader through the development and most crucial findings of porous silica from its first synthesis in 1992 to the present. The article describes constant struggle of researchers to find better solutions to supercapacitors, lower the k value or redox-active hybrids while maintaining robust mechanical properties. Finally, the last section refers to ultra-modern applications of silica such as molecular artificial neural networks or super-dense magnetic memory storage.

Membrane separation is proved to be a powerful tool for several applications such as wastewater treatment or the elimination of various microorganisms from drinking water. In this study, the efficiency of inorganic composite-based multi-walled carbon nanotube (MWCNT) hybrid membranes was investigated in the removal of MS2 bacteriophages from contaminated water. With this object, multi-walled carbon nanotubes were coated with copper(I) oxide, titanium(IV) oxide and iron(III) oxide nanoparticles, respectively, and their virus removal capability was tested in both batch and flow experiments. Considering the possible pH range of drinking water, the filtration tests were carried out at pH 5.0, 7.5 and 9.0 as well. The extent of MS2 removal strongly depended on the pH values for each composite, which can be due to electrostatic interactions between the membrane and the virus. The most efficient removal (greater than or equal to 99.99%) was obtained with the Cu ₂ O-coated MWCNT membrane in the whole pH range. The fabricated nanocomposites were characterized by X-ray diffraction, specific surface area measurement, dynamic light scattering, zeta potential measurement, Raman spectroscopy, transmission electron microscopy and scanning electron microscopy. This study presents a simple route to design novel and effective nanocomposite-based hybrid membranes for virus removal.

Despite recent efforts in modernization of water treatment facilities, the problem of access to healthy drinking water for hundreds of millions of people has still not been solved. A water filter based on Cu-coated nanofibrillated cellulose with controlled porosity was prepared by the “paper-making” method. We have optimized the proper mass and ratio of functionalized and pure nanofibrillated cellulose for the preparation of the filter. MS2 bacteriophages were used to model human pathogenic virions. We tested our filter material in batch experiments and the fixed filters in flow experiments. The fabricated Cu-coated nanofibrillated cellulose filters were characterized by scanning electron microscopy, X-ray diffraction, specific surface area measurement (Brunauer–Emmett–Teller), dynamic light scattering, and inductively coupled plasma mass spectroscopy. Our measurements proved that the fixation of cellulose nanofibers plays a significant role in the degree of virus retention and it greatly enhances the efficiency of the filtration. By using these functionalized water filters, we were able to achieve a virus retention of at least 5 magnitudes (5Log) at three different pH values: 5.0, 7.5, and 9.

We present an experimental study of the longitudinal and transverse relaxation of ensembles of negatively charged nitrogen-vacancy (NV${}^{-}$) centers in a diamond monocrystal prepared by 1.8 MeV proton implantation. The focused proton beam was used to introduce vacancies at a 20 µ$\mathsf{\mu }$m depth layer. Applied doses were in the range of $1.5\times {10}^{13}$ to $1.5\times {10}^{17}$ ions/cm${}^2$. The samples were subsequently annealed in vacuum which resulted in a migration of vacancies and their association with the nitrogen present in the diamond matrix. The proton implantation technique proved versatile to control production of nitrogen-vacancy color centers in thin films.

The Mn₁₂ single-molecule magnets (SMMs) could be attached to the surface of spherical silica for the first time with a high probability. This allowed separation of the individual molecular magnets and direct microscopic observation of the SMMs. We described in detail how to fabricate such a composite material. The synthesis procedure proposed here is simple and efficient. We confirmed the efficiency of the method by transmission electron microscopy (TEM): single-molecule magnets were visible at the surface of a silica substrate. Based on TEM observation, we described how the molecules anchor to the surface of silica (the geometry of the magnetic molecule in regard to the surface of the substrate). The SQUID magnetometry showed that single-molecule magnet behaviour is kept intact after grafting. The attachment of the single-molecule magnets to the surface of silica allows to investigate their properties as separate molecules. This is particularly important in the analysis of magnetic properties such as magnetic states of the separated SMMs, their mutual interactions, and the influence of a silica support.

The ability to organize, separate and manipulate individual molecules and ions on a surface opens up almost unlimited opportunities. However, it often requires complex techniques and a proper support material. With this in mind, we show a new concept of 2D solid solvents and review a simple and efficient procedure which is based on nanostructured forms of silica with anchoring units. We describe silica supports, such as spherical nanoparticles and mesoporous silica structures, as well as review the methods for chemical modification of the surface of silica with the functional groups. Finally, we present a few particular examples of the immobilization of molecules and ions on the surface of 2D solid solvents along with the experimental investigation of the obtained materials.