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Graphene with excellent comprehensive properties has been considered as a promising filler to reinforce ceramics. While numerous studies have been devoted to the improvement of mechanical and electrical properties, incorporating graphene to ceramics also offers new opportunities for endowing ceramics with versatility. In this review, the recent development of graphene/ceramic bulk composites is summarized with the focus on the construction of well-designed architecture and the realization of multifunctional applications. The processing technologies of the composites are systematically summarized towards homogeneous dispersion and even ordered orientation of graphene sheets in the ceramic matrix. The improvement of composites in mechanical, electrical, electromagnetic, and thermal performances is discussed. The novel multifunctional applications brought by smart integration of graphene in ceramics are also addressed, including microwave absorption, electromagnetic interference shielding, ballistic armors, self-monitor damage sensors, and energy storage and conversion.

Hybrid inorganic/organic superlattices provide a new path to access the exceptional properties of 2D materials in bulk quantities for macroscopic applications.

2D transitional metal dichalcogenide (2D-TMDC) materials, as inorganic graphene analogs (IGAs), have been intensively investigated for their novel chemical and physical properties when the thickness is reduced to a few atomic layers, such as MoS 2 , WS 2 , among others. [1] Tantalum disulfide, TaS 2 , one of the TMDC materials, has attracted growing attention recently. In the bulk state, TaS 2 occupies 2H or 1T structure, which is composed of covalently bonded STaS layers. 1T-TaS 2 with Ta in octahedral coordination with S atoms exhibits semiconducting behavior, and it has a commensurate charge density wave (CCDW) phase under 180 K. Adjusted by pressure, the superconductivity of 1T-TaS 2 develops in the CCDW state and survives to very high pressure. [2][3][4] 2H-TaS 2 with Ta in trigonal prismatic coordination with S atoms exhibits metallic behaviors with CDW phase transition (T CDW = 75 K) and superconductivity (T c = 0.8 K). [5][6][7][8] The electrical conductivity of single-crystal 2H-TaS 2 can reach 6.8 × 10 4 S m −1 at room temperature. [9] When the thickness is reduced to a few layers, interesting phenomena have been found, such as gate-tunable phase transition [10] and enhanced superconductivity, [11] which are promising properties for applications like electrical oscillators, [12] fast memories, [13] hydrogen evolution catalyst. [14] Until now, 2D TaS 2 has been mainly synthesized by the mechanical exfoliation method, [15] which is time consuming and of poor reproductivity and low yield. It has been noticed that the exfoliation of TaS 2 seems rather difficult and the atomically thin layers are unstable in ambient environments due to easy oxidation. [16] Complex encapsulation techniques are therefore required to help preserve the samples in air. [16] The chemical vapor deposition method [17] proves to be swift and effective in fabrication of high-quality 2D materials, but large-area synthesis of full-coverage atomically thin material is still in progress. For device applications, solution-based chemical synthesis is particularly important, as the product can be easily integrated into electronic devices.There is a new solution-based strategy to synthesize 2D materials in the form of inorganic/organic superlattice, in which the inorganic layers may get close to the low-dimensional state due to the spatial separation by the organic molecules. In our previous papers, we synthesized a hybrid superlattice with alternating 2D [TiS 2 ] monolayers and organic cations through an electrochemical reaction process. [18] The isolation of the [TiS 2 ] TaS 2 nanolayers with reduced dimensionality show interesting physics, such as a gate-tunable phase transition and enhanced superconductivity, among others. Here, a solution-based strategy to fabricate a large-area foil of hybrid TaS 2 /organic superlattice, where [TaS 2 ] monolayers and organic molecules alternatively stack in atomic scale, is proposed. The [TaS 2 ] layers are spatially isolated with remarkably weakened interlayer bonding, resulting in lattice vibration ...

Dispersing two-dimensional (2D) graphene sheets in 3D material matrix becomes a promising route to access the exceptional mechanical and electrical properties of individual graphene sheets in bulk quantities for macroscopic applications. However, this is highly restricted by the uncontrolled distribution and orientation of the graphene sheets in 3D structures as well as the weak graphene-matrix bonding and poor load transfer. Here, we propose a previously unreported avenue to embed ordered 2D graphene array into ceramics matrix, where the catastrophic fracture failure mode of brittle ceramics was transformed into stable crack propagation behavior with 250 to 500% improvement in the mechanical toughness. An unprecedentedly low dry sliding friction coefficient of 0.06 in bulk ceramics was obtained mainly due to the inhibition of the microcrack propagation by the ordered 2D graphene array. These unique and low-cost 2D graphene array/ceramic composites may find applications in severe environments with superior structural and functional properties.