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A novel mechanochemical method was proposed to reconstruct quickly moisture-degraded HKUST-1. The degraded HKUST-1 can be restored within minutes. The reconstructed samples were characterized, and confirmed to have 95% surface area and 92% benzene capacity of the fresh HKUST-1. It is a simple and effective strategy for degraded MOF reconstruction.

Summary Atomically thin two-dimensional (2D) metal oxides exhibit unique optical, electrical, magnetic, and chemical properties, rendering them a bright application prospect in high-performance smart devices. Given the large variety of both layered and non-layered 2D metal oxides, the controllable synthesis is the critical prerequisite for enabling the exploration of their great potentials. In this review, recent progress in the synthesis of 2D metal oxides is summarized and categorized. Particularly, a brief overview of categories and crystal structures of 2D metal oxides is firstly introduced, followed by a critical discussion of various synthesis methods regarding the growth mechanisms, advantages, and limitations. Finally, the existing challenges are presented to provide possible future research directions regarding the synthesis of 2D metal oxides. This work can provide useful guidance on developing innovative approaches for producing both 2D layered and non-layered nanostructures and assist with the acceleration of the research of 2D metal oxides.

Room-temperature (RT) gas sensors based on low-dimensional materials have rapidly received wide attention in various automation control systems and particularly in the Internet of Things (IoT) platforms due to their...

2D metal sulphides (MSs) have attracted enormous amounts of attention in developing high‐performance gas sensors. 2D noble metal sulphides and their derivatives, however, have been less studied due to their predominant nonlayered crystal structures for inefficient exfoliation, despite their surface and peculiar optoelectronic properties. Herein, we successfully synthesize 2D palladium sulphate (PdSO4) from palladium sulphide (PdS) bulk crystals by liquid‐phase exfoliation, in which the presence of oxygen species in the exfoliation solvent plays a key role in the sulphate transformation. Ultrathin 2D PdSO4 planar nanosheets, with thicknesses of ≈3 nm and submicrometer lateral dimensions, exhibit a broad absorption across the visible spectrum, a narrow bandgap of ≈1.35 eV, and a nanosecond scaled long exciton lifetime, which are all suitable for the visible‐light‐driven optoelectronic gas sensing applications. The 2D PdSO4‐based sensor demonstrates a reversible, selective, and sensitive response toward ppb‐leveled NO2 gas at blue light irradiation, featuring a response factor of ≈3.28% for 160 ppb NO2, a low limit of detection of 1.84 ppb, and a > 3 times response factor enhancement over other gases. Herein, the possibility of realizing 2D ultrathin noble metal sulphide compounds from their nonlayered crystal structures and strong potentials in developing high‐performance chemical sensors is explored.

electromagnetic energy conversion workstations" presents a viable approach to address the above challenge, which requires the development of high-performance microwave absorbing (MA) materials. [1][2][3] Metal-organic frames (MOFs), constructed from potential metal units (e.g., Fe, [4] Co, [5] and Ni [6] ) and organic ligand, are possible idea candidates due to the dazzling collocation, easy-to-lock dielectric/magnetic combination, [7,8] as well as favorable electromagnetic coordination and attenuation. [9][10][11] At present, increasingly stringent performance indicators, such as wide electromagnetic absorption bandwidth (EAB >7 GHz), limit the promotion of MOFs. Fortunately, the micro-engineering of such MOFs with cavities, such as yolk-shell, [12][13][14] macroporous, [15,16] and especially hollow, [17,18] has been demonstrated to reduce the density, suppress eddy current, and improve impedance matching. [19] However, traditional hollow routes, such as the external template methods (e.g., SiO 2 , polystyrene, etc.), [20] have been revealed to be time-consuming, complex, and acid-base corrosion. [21,22] Zeolite imidazole frame-67 (ZIF-67) has been the most studied template, in which Co 2+ ions are connected to imidazole Hollow metal-organic frameworks (MOFs) with careful phase engineering have been considered to be suitable candidates for high-performance microwave absorbents. However, there has been a lack of direct methods tailored to MOFs in this area. Here, a facile and safe Ni 2+ -exchange strategy is proposed to synthesize graphite/CoNi alloy hollow porous composites from Ni 2+ concentration-dependent etching of Zeolite imidazole frame-67 (ZIF-67) MOF and subsequent thermal field regulation. Such a special combination of hollow structure and carefully selected hybrid phase are with optimized impedance matching and electromagnetic attenuation. Especially, the suitable carrier transport model and the rich polarization site enhance the dielectric loss, while more significant hysteresis loss and more natural resonance increase the magnetic loss. As a result, excellent microwave absorbing (MA) performances of both broadband absorption (7.63 GHz) and high-efficiency loss (-63.79 dB) are obtained. Moreover, the applicability and practicability of the strategy are demonstrated. This work illustrates the unique advantages of ion-exchange strategy in structure design, component optimization, and electromagnetic regulation, providing a new reference for the 5G cause and MA field.The ORCID identification number(s) for the author(s) of this article can be found under https://doi.org/10.1002/smtd.202200429.