Retrieving Grain Boundaries in 2D Materials

Abstract

provides a feasible pathway to achieving improved ductility for brittle alloys and ceramics. [9][10][11][12][13] Moreover, GBs prove to be capable of improving the minority carrier collection in polycrystalline CdTe and Cu(In,Ga)Se 2 solar cells, leading to higher efficiencies than their single-crystal counterparts by 24% and 69%, respectively. [14,15] The GB effects tend to be enhanced in 2D materials, owing to unique space dimensionality and reduced Coulomb screening. In that case, GBs can not only directly disrupt the crystalline order, but also become all surface-accessible to permit substantial interactions with external species, providing a profound opportunity to enrich 2D materials with novel attributes.GB engineering at the atomic scale results in not only robust nanostructures but also the modification of material characteristics, which is often unachievable in pristine 2D materials. High-resolution characterization images have revealed that GBs in 2D materials are constructed by well-ordered periodic arrays of dislocation cores. [16,17] Compared with point defects (such as vacancies and impurities) that are highly vulnerable to chemical passivation or thermal annealing, GBs have conserved coordination environments, which are structurally more robust and cannot be eliminated by local structural rearrangements. [18,19] The structural diversity of GBs, enabled by flexible combinations of dislocations and varied chemical makeup, [20,21] adds extra tunability to their properties. The mechanical and electronic performances of 2D materials have been shown to depend on detailed GB microstructures. [22] Novel functionalities pertaining to GBs, such as magnetic centers, [23] catalytic sites, [24] and single photon sources, [25] have been reported. Therefore, engineering 2D materials based on GBs has opened a way to achieving a range of complementary properties through structural and compositional controls.Despite encouraging researches on the GB engineering of 2D materials, the application of GBs in functional devices remains far from being deployable, largely limited by the absence of precise control over detailed GB microstructures. Moreover, the limited understanding of the formation mechanism and structure-property relationships of GBs has also retarded the progress of this field. In this review, we examine the diverse compositions and microstructures of GBs in a range of common 2D materials, from elemental (e.g., graphene, borophene, and black phosphorus) to compound ones (e.g., h-BN, MoS 2 , and ReS 2 monolayers). The kinetic growth mechanism and energy evolution of GBs against variation in The coalescence of randomly distributed grains with different crystallographic orientations can result in pervasive grain boundaries (GBs) in 2D materials during their chemical synthesis. GBs not only are the inherent structural imperfection that causes influential impacts on structures and properties of 2D materials, but also have emerged as a platform for exploring unusual physics and functionalities stemming from dra...

Comparative analysis of the structural, optical, mechanical, and electrical properties of PMMA/PU blend‐based nanocomposites with FeVO4 nanofiller for energy storage devices

“…This separates the two localized states and lessens the likelihood of a barrier forming between them 34 . Furthermore, the increase in charge carriers brought on by FeVO 4 that caused the coalescence of grain boundaries is responsible for this improvement in conductivity 36 . Compared to the PU/PMMA mixture, FeVO 4 ‐PU/PMMA nanocomposites have better conductivity.…”

“…34 Furthermore, the increase in charge carriers brought on by FeVO 4 that caused the coalescence of grain boundaries is responsible for this improvement in conductivity. 36 Compared to the PU/PMMA mixture, FeVO 4 -PU/PMMA nanocomposites have better conductivity. The inclusion of nanomaterials gives systematic organization of NPs in the polymeric matrix, as seen by the XRD and ultraviolet-visible data.…”

2D Ruthenium–Chromium Oxide with Rich Grain Boundaries Boosts Acidic Oxygen Evolution Reaction Kinetics

“…[31,32] Notably, GBs are pervasively in 2D materials due to the coalescence of randomly distributed grains with different crystallographic orientations. [33] Therefore, the design of a 2D ultrathin structure, which combines the coordination unsaturated amorphous phase with a highly conductive crystalline phase, together with the tailored M─O bonds, is a promising structure for greatly boosting the acidic OER kinetics.…”

Large-Scale Growth of Hexagonal Boron Nitride for Anticorrosion

“…15,16 More importantly, it is reported that the failure mechanisms of 2D materials are dominated by grain boundary and thermal cracking. 17 The dissociation of H 2 O is energetically favorable along the grain boundaries, and the interaction between O* and B leads to the accumulation of O atoms, which accelerates the formation of Cu oxide/hydroxide. In this context, continuous h-BN layers with large grain sizes and minimal defects are highly required for better anticorrosion properties.…”

“…Therefore, h-BN is considered to be a promising substitution for graphene as an anticorrosion layer . However, its application is largely limited by the fact that the large-scale growth of 2D h-BN has still not been achieved. , More importantly, it is reported that the failure mechanisms of 2D materials are dominated by grain boundary and thermal cracking . The dissociation of H 2 O is energetically favorable along the grain boundaries, and the interaction between O* and B leads to the accumulation of O atoms, which accelerates the formation of Cu oxide/hydroxide.…”