With the rapid propagation of flexible electronic devices, flexible lithium-ion batteries are emerging as the most promising energy supplier among all of the energy storage devices due to high energy and power densities with good cycling stability.

In this review, we examine recent progress using boron nitride (BN) and molybdenum disulfide (MoS₂) nanostructures for electronic, energy, biomedical, and environmental applications. The scope of coverage includes zero-, one-, and two-dimensional nanostructures such as BN nanosheets, BN nanotubes, BN quantum dots, MoS₂ nanosheets, and MoS₂ quantum dots. These materials have sizable bandgaps, differentiating them from other metallic nanostructures or small-bandgap materials. We observed two interesting trends: (1) an increase in applications that use heterogeneous materials by combining BN and MoS₂ nanostructures with other nanomaterials, and (2) strong research interest in environmental applications. Last, we encourage researchers to study how to remove nanomaterials from air, soil, and water contaminated with nanomaterials. As nanotechnology proceeds into various applications, environmental contamination is inevitable and must be addressed. Otherwise, nanomaterials will go into our food chain much like microplastics.

This review examines three aspects of hexagonal boron nitride (h-BN) nanomaterials: properties, synthesis methods, and biomedical applications. We focus the scope of review on three types of h-BN nanostructures: boron nitride nanosheets (BNNSs, few-layered h-BN, larger than ∼100 nm in lateral dimensions), boron nitride quantum dots (BN QDs, smaller than ∼10 nm in all dimensions, with inherent excitation-dependent fluorescence), and boron nitride dots (BN dots, smaller than ∼10 nm in all dimensions, wide bandgap without noise fluorescence). The synthesis methods of BNNSs, BN QDs, and BN dots are summarized in top-down and bottom-up approaches. Future synthesis research should focus on the scalability and the quality of the products, which are essential for reproducible applications. Regarding biomedical applications, BNNSs were used as nanocarriers for drug delivery, mechanical reinforcements (bone tissue engineering), and antibacterial applications. BN QDs are still limited for non-specific bioimaging applications. BN dots are used for the small dimension to construct high-brightness probes (HBPs) for gene sequence detections inside cells. To differentiate from other two-dimensional materials, future applications should focus on using the unique properties of BN nanostructures, such as piezoelectricity, boron neutron capture therapy (BNCT), and their electrically insulating and optically transparent nature. Examples would be combining BNCT and chemo drug delivery using BNNSs, and using BN dots to form HBPs with enhanced fluorescence by preventing fluorescence quenching using electrically insulating BN dots.

This work examines the structural, electronic, mechanical, optical, and thermal properties of Cr2AC (A = Si, Al, Ga, Ge, and P) MAX phases using density functional theory. These properties are investigated through first-principles calculations within the generalized gradient approximation using the CASTEP software package. The Cr2AC phases exhibit metallic behavior, as confirmed by their electronic band structures, with no bandgap present. Regarding mechanical properties, Cr2SiC and Cr2GeC display superior ductility due to their covalent bonding, while Cr2AlC and Cr2GaC are more brittle due to ionic bonding. The elastic constants confirm the mechanical stability of these compounds, and the analysis of their anisotropic mechanical behavior indicates varying degrees of direction-dependent elasticity. For optical properties, reflectivity and refractive indices calculations suggest that these materials could be useful for optoelectronic applications. Thermal properties, including Grüneisen parameters (γ) and Debye temperatures (ΘD), indicate that Cr2AlC and Cr2PC exhibit exceptional thermal stability, making them promising candidates for thermal barrier coatings. These MAX phases are mechanically stable, and their tunable properties, driven by A-site substitution, expand the range of potential applications in areas such as high-temperature and optoelectronic devices used in hostile environments.

The discovery of quantum dots (QDs) earned a Nobel Prize and has led to widespread applications in research and technology. In this review, we focus on the use of QDs in solid-state solar cells (QDSCs). We begin with an overview of the basic principles of SCs. Then, we discuss how device architecture has developed over recent decades, setting the stage for the final section on fourth-generation solar cells (Perspective section). We also highlight progress in material development, starting with lead- and cadmium-based QDs and progressing to more recent carbon- and perovskite-based QDs. Additionally, we review materials used for electron-transport layers (ETLs) and hole-transport layers (HTLs). The articles also present recent advances in QDSCs across various QD types. In the final section, we recommend that future research focus on three main areas: QD active-layer materials, material interfaces, and device architecture. These efforts could lead to sustainable QDSCs that potentially surpass the Shockley–Queisser (SQ) limit.