Interface confined reactions, which can modulate the bonding of reactants with catalytic centres and influence the rate of the mass transport from bulk solution, have emerged as a viable strategy for achieving highly stable and selective catalysis. Here we demonstrate that 1T′-enriched lithiated molybdenum disulfide is a highly powerful reducing agent, which can be exploited for the in-situ reduction of metal ions within the inner planes of lithiated molybdenum disulfide to form a zero valent metal-intercalated molybdenum disulfide. The confinement of platinum nanoparticles within the molybdenum disulfide layered structure leads to enhanced hydrogen evolution reaction activity and stability compared to catalysts dispersed on carbon support. In particular, the inner platinum surface is accessible to charged species like proton and metal ions, while blocking poisoning by larger sized pollutants or neutral molecules. This points a way forward for using bulk intercalated compounds for energy related applications.

Graphene oxide (GO) can be considered as one of the most visible outcomes of graphene research in terms of large scale production and commercialization prospects. Although GO can be easily prepared by oxidation-exfoliation of graphite in agitated solutions, the size of these sheets is generally limited due to fragmentation along fault lines during chemical oxidation and exfoliation in agitated solutions. In this account, we discuss recent strategies which have been developed for the preparation of large sized graphene oxide (LGO) sheets with lateral sizes >10 μm, using chemically expanded graphite as the starting material. LGO has a much lower density of defects than GO prepared using the conventional Hummers' method and can be readily transformed into graphene by chemical reduction. In addition, the unique advantages of using LGO sheets as a performance enhancer are discussed. Finally, this review also discusses recent advances in the chemical and electrochemical reduction of graphene oxide.

Ti 3 C 2 T x (MXene) exhibits attractive properties in different applications. However, traditional synthesis leads to unsatisfactory yield of two-dimensional (2D) Ti 3 C 2 T x , e.g., lower than 20%, which stems from the strong interactions of potential Ti−Ti bonds and residual Ti−Al bonds between the adjacent Ti 3 C 2 layers, hindering the effective intercalation and delamination. Herein, we propose a facile hydrothermalassisted intercalation (HAI) strategy to boost the yield of 2D sheets, achieving a record high value of 74%. This HAI assists the diffusion and intercalation of reagent effectively, promoting the subsequent delamination; meanwhile, an antioxidant is applied to protect these Ti 3 C 2 T x from oxidation during the HAI process. Therefore, massive Ti 3 C 2 T x 2D sheets can be easily synthesized. Thanks to the synergistic effect of high conductivity and substantial terminated functionalities, these Ti 3 C 2 T x 2D sheets show promising application in supercapacitor, providing a high capacitance of 482 F g −1 . Besides, the ultrafast carrier dynamics results of Ti 3 C 2 T x 2D sheets clearly imply the promising application in photocatalysis due to the relatively long bleaching relaxation time. Our work not only paves the way for the mass production of Ti 3 C 2 T x 2D sheets but also provides insights into their electronic and optical properties. KEYWORDS: hydrothermal-assisted intercalation (HAI), Ti 3 C 2 T x , MXene, high yield, facile

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Low-cost, scalable preparation of high-quality graphene has been a critical challenge that hampers its large-scale application. We here propose a novel, scalable liquidphase exfoliation method in which the intercalation, expansion, and exfoliation of graphite are achieved all under ambient conditions, not involving any heating or high-temperature treatment. We demonstrate that such room-temperature liquid-phase intercalation and expansion allow graphite flakes to expand up to 1000 times. Significantly different from thermally expanded graphite, the resulting chemically expanded graphite (CEG) exhibits a uniform, open, porous structure with a specific surface area (847 m2/g) comparable to the theoretical value of three-layer graphene. The CEG obtained is able to be exfoliated under mild conditions to give high-quality graphene with a yield of 70% relative to the starting graphite. The exfoliated graphene sheets have very few defects, with an atomic ratio of carbon to oxygen (C/O ratio) of 28. The as-prepared graphene exhibits an electrical conductivity of 1.17 × 105 S/m and the corresponding transparent films also reveal superior optical and electrical performance.