Nonlayered materials are constructed with chemical covalent bonds in all three dimensions, distinct from layered materials, which contain evident structural differences in the horizontal and vertical directions. As a consequence, liquid‐phase exfoliation (LPE), a widely explored technique to obtain 2D layered nanoarchitectures, has not yet been fully characterized for the realization of 2D nonlayered nanostructures. Herein, by virtue of a typical chain‐like structure of crystalline bulk Te with strong TeTe covalent bonds in intrachains and weak Van der Waals forces in interchains, ultrathin 2D nonlayered Te nanosheets are realized by means of an LPE method. The resultant 2D Te nanosheets possess a broad lateral dimension ranging from 41.5 to 177.5 nm and a thickness ranging from 5.1 to 6.4 nm, and its photoresponse properties are evaluated using photoelectrochemical measurements. The 2D Te nanosheets exhibit excellent photoresponse behaviors from the UV to the visible regime in association with strong time and cycle stability for the on/off switching behaviors. The fabrication approach of 2D Te nanosheets would arouse interest in exfoliating other nonlayered 2D materials, which would expand the family of 2D materials.

2D transition metal carbides or nitrides, known as MXenes, are a new family of 2D materials with close to 30 members experimentally synthesized and dozens more theoretically investigated. Because of the abundant surface terminations, MXenes have been compounded with various materials by multi-interactions. In addition to the prevented aggregation and oxidation of MXene flakes, the MXene/polymer membranes exhibit outstanding mechanical, thermal, and electrical properties due to the synergistic effects. However, relatively little is currently known about the MXene/polymer membranes and a special review on the progress of the synthesis, properties, and applications of MXene/polymer membranes has not been reported to date. Herein, this Review starts with an introduction of the synthesis and properties of MXenes. Then the development of MXene/polymer membranes will be discussed, which aims to summarize various approaches of fabricating MXene/polymer membranes and their fascinating properties. The focus then turns to their exciting potential applications in various fields such as filtration, electromagnetic interference (EMI) shielding, energy storage devices, wearable electronics, etc. Finally, outlooks and perspectives for the future challenges and prospects of MXene/polymer membranes are provided.

Two-dimensional (2D) monoelemental bismuth (Bi) crystal, one of the pnictogens (group VA), has recently attracted increasing interest because of its intriguing characteristics. Here, uniformly sized 2D Bi quantum dots (BiQDs) with an average diameter (thickness) of 4.9 ± 1.0 nm (2.6 ± 0.7 nm) were fabricated through a facile liquid-phase exfoliation (LPE) method, and the corresponding photoresponse was evaluated using photoelectrochemical (PEC) measurements. The as-fabricated BiQDs-based photodetector not only exhibits an appropriate capacity for self-driven broadband photoresponse but also shows high-performance photoresponse under low bias potentials ranging from UV to visible light in association with long-term stability of the ON/OFF switching behavior. In terms of these findings, it is further anticipated that the resultant BiQDs possess promising potential in UV–visible photodetection as well as in liquid optoelectronics. Our work may open a new avenue for delivering high-quality monoelemental pnictogen QDs from their bulk counterparts, thereby expanding interest in 2D monoelemental materials.

Low dimensional materials based sensors have improved the detection strategy for sensing complex substances present in environment and human body.

Graphdiyne (GDY), a newly emerging 2D carbon allotrope, has been widely explored in various fields owing to its outstanding electronic properties such as the intrinsic bandgap and high carrier mobility. Herein, GDY‐based photoelectrochemical‐type photodetection is realized by spin‐coating ultrathin GDY nanosheets onto flexible poly(ethylene terephthalate) (PET) substrates. The GDY‐based photodetectors (PDs) demonstrate excellent photo‐responsive behaviors with high photocurrent (Pph, 5.98 µA cm‐2), photoresponsivity (Rph, 1086.96 µA W‐1), detectivity (7.31 × 1010 Jones), and excellent long‐term stability (more than 1 month). More importantly, the PDs maintain an excellent Pph after 1000 cycles of bending (4.45 µA cm‐2) and twisting (3.85 µA cm‐2), thanks to the great flexibility of the GDY structure that is compatible with the flexible PET substrate. Density functional theory (DFT) calculations are adopted to explore the electronic characteristics of GDY, which provides evidence for the performance enhancement of GDY in alkaline electrolyte. In this way, the GDY‐based flexible PDs can enrich the fundamental study of GDY and pave the way for the exploration of GDY heterojunction‐based photodetection.

suffered by metal-chalcogen batteries, due to the insolubility of both the intermediate (ZnTe 2) and final (ZnTe) product. This work presents a new direction to design conversion-type rechargeable aqueous ZIBs with high capacity, stable output potential, excellent rate capability and long cyclic performance.

Tellurium (Te), as one of the rarest stable solid elements far more common in the universe than on earth, is a p‐type semiconductor with excellent optical properties. Herein, a novel two‐dimensional (2D) Te nanosheets (Ns)‐based air‐stable nonlinear photonic devices: all‐optical switcher and photonic diode, owing to its strong light–matter interaction in the visible‐to‐infrared band are reported. The findings validate that the proposed photonic diode can be utilized for the function of nonreciprocal light propagation in optical telecommunications or integrated photonics. Moreover, 2D Te‐based light‐modulate‐light system is successfully designed to realize “ON” and “OFF” modes for all‐optical switching operation. This work highlights a good promise of 2D Te in the field of nonlinear photonics, leading to an important step toward 2D Te‐based advanced photonics devices. The versatile solution process allows a universal access of 2D Te as a new 2D material in a wider range of photonics device applications such as, detector, modulator, switcher, etc.

Graphdiyne is a new carbon allotrope comprising sp‐ and sp2‐hybridized carbon atoms arranged in a 2D layered structure. In this contribution, 2D graphdiyne is demonstrated to exhibit a strong light–matter interaction with high stability to achieve a broadband Kerr nonlinear optical response, which is useful for nonreciprocal light propagation in passive photonic diodes. Furthermore, advantage of the unique Kerr nonlinearity of 2D graphdiyne is taken and a nonreciprocal light propagation device is proposed based on the novel similarity comparison method. Graphdiyne has demonstrated a large nonlinear refractive index in the order of ≈10−5 cm2 W−1, comparing favorably to that of graphene. Based on the strong Kerr nonlinearity of 2D graphdiyne, a nonlinear photonic diode that breaks time‐reversal symmetry is demonstrated to realize the unidirectional excitation of Kerr nonlinearity, which can be regarded as a significant demonstration of a graphdiyne‐based prototypical application in nonlinear photonics and might suggest an important step toward versatile graphdiyne‐based advanced passive photonics devices in the future.