Research on two-dimensional (2D) materials has been explosively increasing in last seventeen years in varying subjects including condensed matter physics, electronic engineering, materials science, and chemistry since the mechanical exfoliation of graphene in 2004. Starting from graphene, 2D materials now have become a big family with numerous members and diverse categories. The unique structural features and physicochemical properties of 2D materials make them one class of the most appealing candidates for a wide range of potential applications.In particular, we have seen some major breakthroughs made in the field of 2D materials in last five years not only in developing novel synthetic methods and exploring new structures/properties but also in identifying innovative applications and pushing forward commercialisation. In this review, we provide a critical summary on the recent progress made in the field of 2D materials with a particular focus on last five years. After a brief background 物理化学学报 Acta Phys. -Chim. Sin. 2021, 37 (12), 2108017 (3 of 151) introduction, we first discuss the major synthetic methods for 2D materials, including the mechanical exfoliation, liquid exfoliation, vapor phase deposition, and wet-chemical synthesis as well as phase engineering of 2D materials belonging to the field of phase engineering of nanomaterials (PEN). We then introduce the superconducting/optical/magnetic properties and chirality of 2D materials along with newly emerging magic angle 2D superlattices. Following that, the promising applications of 2D materials in electronics, optoelectronics, catalysis, energy storage, solar cells, biomedicine, sensors, environments, etc. are described sequentially. Thereafter, we present the theoretic calculations and simulations of 2D materials. Finally, after concluding the current progress, we provide some personal discussions on the existing challenges and future outlooks in this rapidly developing field.

A strategy to improve reaction activity via the photothermal effect of plasmonic semiconductor nanomaterials is demonstrated in a core–shell structured catalyst.

A novel strategy based on the concept of preorganization and cooperation has been designed for a superior capacity to capture low-concentration CO by imide-based ionic liquids. By using this strategy, for the first time, an extremely high gravimetric CO capacity of up to 22 wt % (1.65 mol mol ) and excellent reversibility (16 cycles) have been achieved from 10 vol. % of CO in N when using an ionic liquid having a preorganized anion. Through a combination of quantum-chemical calculations and spectroscopic investigations, it is suggested that cooperative interactions between CO and multiple active sites in the preorganized anion are the driving force for the superior CO capacity and excellent reversibility.

Acid gases such as SO 2 can be absorbed by ionic liquids (ILs) because of their unique properties. In this work, we developed a new approach for improving SO 2 absorption by novel acylamido-based anion-functionalized ILs. Several kinds of such ILs with different structures of acylamido group (anionic acylamide) were designed, prepared, and used for efficient capture of SO 2 . It was shown that these acylamido-based ILs strongly interacted with SO 2 , resulting in a very high SO 2 capacity up to ∼4.5 mol SO 2 per mole of IL. The interactions between acylamido-based ILs and SO 2 were investigated by FT-IR, NMR, and quantum chemical calculations. It was found that the dramatic enhancement of SO 2 absorption capacity was originated from the multiple-site interactions such as N···S and CO···S interactions between the anion and SO 2 . Furthermore, the captured SO 2 was easy to release by heating or bubbling N 2 through the SO 2 -saturated ILs. This novel strategy provides an excellent alternative to current SO 2 capture technologies.Controlling and minimizing the emissions of such acid gas as SO 2 are highly important, because SO 2 is a significant source of atmospheric pollution that threatens environment and human health. Novel materials and processes for efficient, reversible and economical capture of SO 2 are highly desired to develop and are of critical importance for environmental protection. Although several conventional removal processes, such as limestone scrubbing and ammonia scrubbing, have been used for flue gas desulfurization (FGD), the inherent disadvantages of these technologies should not be ignored, including the production of large quantities of wastewater and useless byproducts. 1−3Recently, ionic liquids (ILs) have been proposed as better acid gas absorbents due to their unique properties, such as extremely low vapor pressure, wide liquid temperature range, nonflammability, chemical stability, and tunable structure and properties. 4−12 SO 2 has a high solubility in some ILs through physical interaction, 13−15 especially in ether-functionalized ILs. 16,17 However, effective capture of SO 2 from flue gas requires strong interaction between IL and SO 2 because of the relatively low SO 2 partial pressure in this stream. Han et al. 18 reported the first example for chemical absorption of SO 2 by 1,1,3,3-tetramethylguandinium lactate ([TMG][L]), which absorbed about 1.0 mol SO 2 per mole of IL at 1 bar with 8% SO 2 in a gas mixture of SO 2 and N 2 . Since then, other kinds of ILs, such as hydroxyl ammonium ILs, 19,20 imidazolium ILs, 14,21−23 thiocyanate ILs, 24−26 phenolate ILs, 27,28 poly-(ILs), 29,30 and supported IL membranes (SILMs) 31,32 were used to capture and separate SO 2 . Recently, Wang et al. 33−36 reported a new strategy for acid gas absorption by tunable azolate-ILs and found that trihexyl(tetradecyl) phosphonium tetrazolate ([P 66614 ][Tetz]) could capture 3.72 mol SO 2 per mole IL through multiple-site interactions between anion and SO 2 . 33 Other groups studied the performance of car...