The increasing life expectancy, the growing senior population and more generalized wealth are only some of the many driving forces for the current strong effort in the research area of biomaterials. Indeed, improved biocompatible, bioactive, antimicotic, antiseptic and antibacterial materials are needed for substituting aged or injured tissues of the human body, as well as for the cure of diseases affecting them. Another current and dramatic challenge is the development of good, clean, and efficient materials for energy storage, decreasing CO₂ emissions by using only renewable energies, instead of fossil fuels. Hydrogen-based solutions are promising key technologies to boost this energy transition, thereby improving energy storage efficiency.

Recent evolutions in High Performance Computing (HPC) architectures and the concurrent development of more efficient quantum-mechanical softwares have dramatically increased the size and complexity of the systems that can be modeled by a variety of ab initio methods, at a very high accuracy level. One of the areas that greatly benefits from these advancements is materials science: surfaces and interfacial phenomena, defective solids, functional materials, and nano-particulate systems, all require models that are hardly handled by desktop computing architectures due to the large system size.

Some recent applications of periodic large-scale DFT simulations are presented, ranging from various surfaces of hydroxyapatite - the main constituent of the inorganic phase of bones and teeth - in interaction with several biomolecules, to the investigation of cyclodextrin-based nanosponges as drug carriers. The case of materials for solid-state hydrogen storage in alloys and inorganic materials complete this broad and challenging scenario.

The structure of active sites, the H- bonding pattern, the relative stability and the interaction energy, as well as thermodynamic propertiesare can be derived by quantum-mechanical calculations. Moreover, the simulation of IR spectra provide a direct comparison with the experimental data, helping in the interpretation of the mechanisms occurred at the different surfaces or interfaces. The joint use of experimental and computational techniques has indeed revealed very effective to improve in the field of advanced materials, as biomaterials and hydrogen storage materials.

Following the global water crisis, advanced countries have different methods to solve this issue. The industrial pigment is one of the first recognizable contaminants and creates an unfavorable appearance. Synthetic dyes are used in a wide range of advanced technologies, including paper, plastics, rubber, leather, food production, cosmetics, textiles, and dyeing. Several methods have been proposed to remove these materials. These methods include membrane filtration, coagulation, advanced oxidation, ozonation, electrical-coagulation, and adsorption, photocatalyst. All of these methods have their advantages and disadvantages. Among these methods, adsorption and degradation by photocatalytic hydrogels has been confirmed compared to other methods due to low cost and simplicity of operation and has one the best performance in removing pigment from effluents, and one Technology is effective. Photocatalytic and Polymeric superadsorbents are considered appropriate for retrieving and removing metals and metal cations due to their features such as unique structure, reasonable price, ease of use, reusability, and high chemical and mechanical resistance.

Green chemistry started for the search of benign methods for the development of nanoparticles from nature and  their use in the field of  antibacterial, antioxidant, and antitumor applications. Bio wastes are eco-friendly starting materials  to produce typical nanoparticles with well-defined chemical composition, size, and morphology. Cellulose, starch, chitin and chitosan are the most abundant biopolymers around the world.   All are under the polysaccharides family in which cellulose is one of the important structural components of the primary cell wall of green plants. Cellulose nanoparticles (fibers, crystals and whiskers) can be extracted from agrowaste resources such as  jute, coir, bamboo, pineapple leafs, coir etc. Chitin is the second most abundant biopolymer after cellulose, it is a characteristic component of the cell walls of fungi, the exoskeletons of arthropods and nanoparticles of chitin (fibers, whiskers) can be extracted from shrimp and crab shells. Chitosan is the derivative of chitin, prepared by the removal of acetyl group from chitin (Deacetylation).  Starch nano particles can be extracted from tapioca and potato wastes. These nanoparticles can be converted into smart and functional biomaterials by functionalization through chemical modifications (esterification, etherification, TEMPO oxidation, carboxylation and hydroxylation etc) due to presence of large amount of hydroxyl group on the surface. The preparation of these nanoparticles includes both series of chemical as well as mechanical treatments; crushing, grinding, alkali, bleaching and acid treatments. Transmission electron microscopy (TEM), scanning electron microscopy (SEM) and atomic force microscopy (AFM) are used to investigate the morphology of nanoscale biopolymers. Fourier transform infra-red spectroscopy (FTIR) and x ray diffraction (XRD) are being used to study the functional group changes, crystallographic texture of nanoscale biopolymers respectively. Since large quantities of bio wastes are produced annually, further utilization of cellulose, starch  and chitins as functionalized materials is very much desired. The cellulose, starch  and chitin nano particles are currently obtained as aqueous suspensions which are used as reinforcing additives for high performance environment-friendly biodegradable polymer materials. These nanocomposites are being used as   biomedical composites for drug/gene delivery, nano scaffolds in tissue engineering and cosmetic orthodontics. The reinforcing effect of these nanoparticles results from the formation of a percolating network based on hydrogen bonding forces. The incorporation of these nano particles in several bio-based polymers have been discussed. The role of nano particle dispersion, distribution, interfacial adhesion and orientation on the properties of the ecofriendly bio nanocomposites have been carefully evaluated. 

Bismuth oxyhalides (BiOX, X= F, Cl, Br and I) and their composites have been successfully synthesized using different leaf extracts. Leaf extract is known to possess anti-oxidant and stabilizing properties that aids in the immediate reduction and stabilization of the metal ions into their corresponding nanostructures. To obtain a better understanding of the results, the BiOX and their composites were also synthesized by hydrolysis method (without leaf extract). The synthesized photocatalyst was characterized using SEM, XRD, FTIR, UV-vis DRS etc. A comparative study was envisaged between both BiOX and its composites towards the degradation of organic pollutants. The results revealed that leaf extract mediated BiOX and its composites led to much higher degradation of organic pollutants as compared to the without leaf extract synthesized BiOX photocatalysts under visible light irradiation. The enhanced photocatalytic activity was attributed to the role of leaf extract that added some additional features to BiOX and their composites such as smaller size, mesoporous structure with higher surface area, lower band gap and effective separation of electron-hole pairs.