Advanced Materials and Nano Systems: Theory and Experiment (Part-1)

We present the recent progress in hydrogen storage in carbon and boron nitride nanostructures. Carbon and boron nitride nanostructures are considered advantageous in this prospect due to their lightweight and high surface area. Many researchers highlight the demerits of pristine structures to hold hydrogen molecules for mobile applications. In such cases, weak van der Waals interaction comes into account. Hence, the hydrogen molecules make weak bonds with the host materials and, therefore, weak adsorption energy and low hydrogen molecules uptake. So, to tune the adsorption energy and overall kinetics, methods such as doping, light alkali-alkaline earth metals decoration, vacancy, functionalization, pressure variation, application of external electric field, and biaxial strain have been adopted by many researchers. Physisorption with atoms decoration is promising for hydrogen storage applications. Under this condition, the host materials have high storage capacity, average adsorption energy and feasible adsorption/desorption kinetics.

Artificial vision for blind patients suffering from retinal diseases has shown promising results in the last two decades, especially after the advancement in CMOS technology. In the modern era, two types of retinal implant techniques are very popular, one is the epiretinal implant and the other is the subretinal implant technique. Even though the method of data processing is different in the above-mentioned techniques, utilization of appropriate nanomaterial for the durability of the implant has always been a major concern. Materials such as titanium nitride (TiN), iridium oxide (IrOx), platinum grey, and carbon nanotube (CNT) were employed in recent years in many retinal prosthetic projects. Manufacturing of stimulating electrodes and coating of electronic devices to avoid infiltrations are the two important applications where nanomaterials are utilized in the retinal implant system. This chapter discusses the important and desired physical properties of nanomaterials viz. conductivity, tensile strength, absorption of photons, and adsorption of water molecules for the subretinal implant technique. Since the implant is located inside the retina, the isolated and corrosive environment is the main challenge. This study is based on the first-principles of density functional theory (DFT). Considering the recent advancements, the materials are comparatively analyzed, and new nanomaterial is also suggested.

As the world progresses towards sustainable energy and concomitant decarbonization of its electrical supply, modern civilization is approaching the fourth industrial revolution with a boom of digital devices and innovative technologies. As a result, the demand for high-performance batteries has skyrocketed, and many research initiatives for the design and development of high-performance rechargeable batteries are being taken. With the incremental standardization of battery designs, enhancement in their performance mainly relies on technical advancement in key electrode materials (cathode and anode materials). This chapters reviews the state-of-the-art materials used in fabricating electrodes, including a description of their structures and storage mechanisms and modification of commonly used materials for electrode working either in the solid-state or in the solution for aqueous or non-aqueous electrolytes. Based on the appropriate metrics such as operating voltage, specific energy, capacity, cyclic stability and life cycle, the performance of different electrodes has also been assessed. Along with the recent advancement, pertaining limitations are briefly covered and analyzed with some viable solutions in the pursuit of cathode and anode materials with fast kinetics, high voltage, and long cycle life.

The production of ammonia is facilitated by the nitrogen reduction reaction (NRR), where the inert di-nitrogen molecule is converted to ammonia. Along with being a major carrier of hydrogen, ammonia holds authority in the fertilizer realm. Therefore, it is inevitable to develop a viable and eco-friendly method of production that is cost-effective and resource-efficient. The primary challenge of nitrogen reduction is the cleavage of the particularly stable nitrogen bond. The most popular Haber-Bosch process for ammonia production, although efficient, is highly energy-intensive, and the need for maintaining exceptionally high temperature and pressure conditions is an environmental concern. As an alternative, the direct conversion of nitrogen has been carried out by photocatalysis and electrocatalysis. However, this strategy falls short of achieving superior conversion efficiencies. Consequently, it is conceivable that a fitting catalyst can be the solution for the difficulties associated with NRR. Over the years, several attempts have been made at formulating the best catalyst, including chromium oxynitride nanoparticles, niobium dioxide, various metal (Ru, Al, Rh, Ga) clusters, single-atom catalysts supported on different surfaces, and doubleatom catalysts. Recently, perovskites have emerged into the spotlight as excellent catalysts for NRR. In this chapter, we discuss the challenges faced by researchers to formulate righteous catalysts for the sustainable reduction of nitrogen by studying each of these types with a few examples. We also review the recent advancements in the experimental domain of NRR using different electrochemical cells.

 Nanocomposites offer an exclusive advantage over bulk materials in terms of efficiency on account of their greater surface area, higher reactivity, ease of modification, good dispersion, and hence, multi-faceted applications. The various forms of nanocomposites derived from low-cost resources, especially carbon-based materials, are of unique interest. Activated carbons offer the unique advantage as the matrix for nanocomposites synthesis due to their graphite structure, thereby providing strength and the ease of modification on the surface of nanocomposites while introducing desired functional groups. Apart from this, they are widely popular for their large surface area and porosity. Therefore, carbon-based nanocomposites offer vivid applications in various fields, such as environmental remediation as adsorbents, suitable sorbents in the analytical determination of organics, targeted drug delivery, diagnostic agents, fuel cells and sensors, to name a few. Amongst these, the role of nanocomposites as sensors and environmental remediation tools has been studied extensively. The varied modes of action include adsorption, nano-catalysis, membrane filtration, etc ., for pollutants ranging from inorganic ions, heavy metals, pesticides, dyes, anti-bacterials, oil spills, and many more. However, there are constraints in their stability, cost, storage and disposal triggered by varying environmental conditions.This chapter presents a review of the synthesis, application and challenges of nanostructured composite materials in environmental remediation. 

To reveal the concentration-dependent optical properties of aqueous, ethanol and toluene binary solutions, the refractometry method was used. The peak of refractive indices corresponds to formed heteromolecular complexes with a certain concentration. The bonds between the molecules formed in mixtures are also directly related to their chemical structure. The bonds that form between polar and non-polar compounds and also between polar protic and polar aprotic compounds are different. All solutions were measured in the concentration range ~0÷1 mole fraction at room temperature. In our work, we have shown that, along with Infrared and Raman spectroscopy, the refractometric method is effective for the determination of formed structures in mixtures.

Nanotechnology is one of the most promising new technologies in the recent decade, which involves structures, devices, and systems with novel properties and functions due to their atomic arrangement on scales of 1–100 nm. In general, the materials at the nanoscale have unique physical, mechanical, chemical, and biological properties compared to their bulk materials. Thus, these properties lead to a new novelty and variety of technological applications in the different fields (physics, science and engineering, electrical and computer science, materials, chemistry, biology, and medicine). This chapter provides a brief introduction of nanotechnology, nanomaterials, and their applications while discussing structural, optical, and magnetic properties as well as antibacterial activities. This chapter overviews the current research being carried out on the properties and application of metal oxide nanoparticles, especially chromium oxide (Cr2O3 ) nanoparticles, indium oxide nanoparticles (In2O3 ), and magnesium oxide (MgO) nanoparticles. These materials are considered novel materials for biological and smart applications, such as antimicrobial, drug delivery systems, and cancer therapy. Multi-drug and antibiotic resistance are among the great challenges that confront researchers in designing and developing efficient antimicrobial and biomedical agents. Inspired by the remarkable developments in nanoparticles in recent times, antibacterial metal oxide nanoparticles have been discovered as potential antibiotics to restrict infectious diseases. Thus, the mechanism of anti-microbial activities of metal oxide nanoparticles is discussed here in detail. In this chapter, a brief literature survey related to the present study is also performed. By the end of the chapter, the concluding remarks with views on the recent progress and future challenges of metal oxide nanoparticles are appended.

Orthopaedic implant materials have an important role in the field of medical science. Characteristics of implant materials such as rigidity, corrosion, biocompatibility, surface morphology, tissue receptivity, and stability are the key factors that influence the choice of the implant material. The mechanical properties of the implants are one of the significant factors for bone substitution. To understand the mechanical properties of these solid substitutes, the use of solid mechanics, which is intended for general structural analysis of 2-dimensional and 3-dimensional bodies is vital. In this study, 3-dimensional modelling of implant and simulation using the finite element analysis software were incorporated to investigate the effect of load direction on the stress distribution in different orthopaedic implant materials. 

This chapter accentuates the latest breakthrough in the advanced and intelligent materials' catalysis, sensing and wastewater treatment applications. The various engineered materials are securing the interest of researchers for optimized technical utilizations. This chapter discusses the number of catalytic and sensing operations of advanced and intelligent materials in detail. Catalysis and sensing phenomena involve the conversion of obtained signals into a readable format, and advanced materials with their superior optical, semiconducting or physical properties are studied widely. However, wastewater treatment needs adsorption and advanced oxidation of the different types of contaminants by the advanced materials. The list of advanced materials includes many organic/inorganic and natural/synthetic platforms with desired properties. These advanced materials have high biocompatibility and easy biodegradable characteristics. With the latest synthesis and functionalization methods, these advanced materials are becoming nanohybrid systems. This chapter covers implementing these nanohybrid systems for catalysis, wastewater treatment and sensing. The first half of the chapter focuses on introducing the basic catalytic, sensing and wastewater processes based on the application of advanced materials. However, the second half includes introducing various advanced materials in the techniques mentioned above.

Topological materials are characterized by a unique band topology that is prominently distinct from ordinary metals and insulators. This new type of quantum material exhibits insulating bulk and conducting surface states that are robust against time-reversal invariant perturbations. In 2009, Bi2Se3 , Sb2Te3 and Bi2Te3 were predicted as 3D Topological insulators (TIs) with a single Dirac cone at the surface state. For application purposes, however, bulk conductivity due to Se vacancy in Bi2Se3 or antisite defects in Bi2Te3 has been a challenging issue. In order to achieve an enhanced surface conductivity over the bulk, nanomaterials are irreplaceable. Nanostructures' high surface to volume ratio provides a good platform for investigating the topological existence of surface states. By tuning the position of Fermi level through field effect gating, it is also possible to terminate the bulk residual carriers. Moreover, the synthesis of nanomaterials allows for morphological, electronic, and chemical regulation, resulting in the ability to design structures with desired TI properties at the nanoscale. In this article, we review various technological applications of nanostructured topological insulators. We also survey the implementation of topological nanomaterials in the field of optoelectronic devices, p-n junction, superconducting materials, field effect transistor, memory device and spintronics, ultrafast photodetection, and quantum computations. 

Hollow structures are one of the most highlighted topics of research in nanotechnology. These hollow structures can be in the form of nanospheres, nanocages, nanorods, nano boxes, etc. They can be single-layered or multi-layered, with different kinds of doping. All these variations in hollow structures open up various fields of research, from biomedicines to optoelectronics. With the discovery of hollow structures like carbon buckyball, nanotubes, etc., several application-based -research was carried out, both theoretically as well as experimentally. Modifications are observed in the properties of a material when formed in a hollow shape like better conductivity, trapping capacity, catalytic effect, etc. These properties were the highlight of the studies. This field is still under investigation, and there is a lot of scope for new possibilities in the future. This chapter covers the basic information about different kinds of hollow structures like carbon buckyball, variations in their properties, along with recent developments and their applications. This chapter also includes detailed research about buckyball structures of ZnO, ZnS, and Al-doped ZnO using simulations with their comparative study and future applications.