A world-wide growing concern relates to the rising levels of CO₂ in the atmosphere that leads to devastating consequences for our environment. In addition to reducing emissions, one alternative strategy is the conversion of CO₂ (via the CO₂ Reduction Reaction, or CO₂RR) into added-value chemicals, such as CO, HCOOH, C₂H₅OH, CH₄, and more. Although this strategy is currently not economically feasible due to the high stability of the CO₂ molecule, significant progress has been made to optimize this electrochemical conversion, especially in terms of finding a performing catalyst. In fact, many noble and non-noble metal-based systems have been investigated but achieving CO₂ conversion with high faradaic efficiency (FE), high selectivity towards specific products (e.g., hydrocarbons), and maintaining long-term stability is still challenging. The situation is also aggravated by a concomitant hydrogen production reaction (HER), together with the cost and/or scarcity of some catalysts. This review aims to present, among the most recent studies, some of the best-performing catalysts for CO₂RR. By discussing the reasons behind their performances, and relating them to their composition and structural features, some key qualities for an “optimal catalyst” can be defined, which, in turn, will help render the conversion of CO₂ a practical, as well as economically feasible process.

In this work, two different composite nanostructures, YAG:Ce and Ga_0.9In_0.1N, were prepared by the Urea Glass Route method and tested for the production of white light. The first composite was prepared by synthetizing the Ga_0.9In_0.1N nanoparticles in the presence of YAG:Ce nanoparticles. The second one was prepared by synthetizing YAG:Ce nanoparticles in the presence of Ga_0.9In_0.1N nanoparticles. These systems can be useful for the production of white light. X-ray Diffraction and Transmission and Scanning Electron Microscopies (TEM and SEM) were used to evaluate their structural and morphological properties. Excitation and emission spectra, the quantum yield and colour of the emitted light were acquired to evaluate the optical properties of the systems.

Iron-based magnetic nanomaterials have evolved into a versatile platform that integrates tuneable magnetic, electronic, and catalytic properties with chemical abundance and sustainability. While classical ferrites such as Fe ₃ O ₄ and γ -Fe ₂ O ₃ established the foundations for magnetic sensing, biomedical imaging, and environmental remediation, emerging demands for higher magnetic response, stronger field-induced heating, tailored spin polarization, and enhanced conductivity have driven a transition toward Fe-based alloys, carbides, nitrides, and heterostructured composites. These advanced phases offer expanded control over saturation magnetization, anisotropy, relaxation dynamics, and interfacial chemistry, unlocking capabilities that conventional oxides cannot achieve. This review unifies recent progress across magnetic fundamentals, synthesis, and cross-sector applications. We first outline the key magnetic phenomena that govern functional performance, including superparamagnetism which is primarily observed in nanoparticles with a particle size of less than 10 nm, magnetic anisotropy, phase-dependent magnetism, surface/interface spin disorder, and magnetothermal dissipation. We then highlight state-of-the-art synthetic strategies, ranging from metal–organic framework-derived architectures and non-equilibrium phase engineering to hybrid core–shell and heterostructured systems, that enable precise control over composition, crystallinity, and metastable magnetic phases. Finally, we map these materials onto major technological domains, emphasizing how their magnetic and catalytic attributes drive advances in electrocatalysis (oxygen evolution reaction; hydrogen evolution reaction; and oxygen reduction reaction), energy storage and electronics (Li-ion batteries, Zn–air, spintronics), biomedicine (magnetic resonance imaging, magnetic hyperthermia, targeted drug delivery and magnetic particle imaging), and environmental remediation (wastewater treatment, dye degradation, and heavy metal removal). By integrating magnetic physics with chemical design and application engineering, this review provides an integrated framework for understanding and optimizing Fe-based nanomaterials. We conclude by identifying key challenges, including stabilization of non-equilibrium phases, achieving corrosion-resistant high-saturation magnetization systems, mechanistic spin-reactivity coupling, and the need for data-driven discovery, and outline a roadmap for accelerating the translation of iron-based magnetic materials into next-generation sustainable technologies.