A large number of novel two-dimensional (2D) materials are constantly being discovered and deposited in databases. Consolidated implementation of machine learning algorithms and density functional theory (DFT)-based predictions have allowed the creation of several databases containing an unimaginable number of 2D samples. As the next step in this chain, the investigation leads to a comprehensive study of the functionality of the invented materials. In this work, a family of transition metal dichlorides have been screened out for systematic investigation of their structural stability, fundamental properties, structural defects, and environmental stability via DFT-based calculations. The work highlights the importance of using the potential of the invented materials and proposes a comprehensive characterization of a new family of 2D materials.

The allotropes of a new layered material, phosphorus carbide (PC), have been predicted recently and a few of these predicted structures have already been successfully fabricated. Herein, by using first-principles calculations we investigated the effects of rippling an α-PC monolayer, one of the most stable modifications of layered PC, under large compressive strains. Similar to phosphorene, layered PC was found to have the extraordinary ability to bend and form ripples with large curvatures under a sufficiently large strain applied along its armchair direction.The band gap size, workfunction, and Young's modulus of rippled α-PC monolayer are predicted to be highly tunable by strain engineering. Moreover, a direct-indirect band gap transition is observed under the compressive strains in a range from 6 to 11%. Another important feature of α-PC monolayer rippled along the armchair direction is the possibility of its rolling to a PC nanotube (PCNT) under extreme compressive strains. These tubes of different sizes exhibit high thermal stability, possess a comparably high Young's modulus, and a well tunable band gap which can vary from 0 to 0.95 eV. In addition, for both structures, rippled α-PC and PCNTs, we have explained the changes of their properties under compressive strain in terms of the modification of their structural parameters.Electronic structure of the α-PC monolayer Figure S1. The atomic (upper panel) and the band (lower panel) structures of rippled α-PC monolayer under compressive strain in a range from 0 to 48%. Atomic and electronic structures of α-PC nanotube

Polysaccharide biopolymers are biomacromolecules derived from renewable resources with versatile functions including thickening, crosslinking, adsorption, etc. Possessing high efficiency and low cost, they have brought wide applications in all phases of petroleum recovery, from well drilling to wastewater treatment. The biopolymers are generally utilized as additives of fluids or plugging agents, to correct the fluid properties that affect the performance and cost of petroleum recovery. This review focuses on both the characteristics of biopolymers and their utilization in the petroleum recovery process. Research on the synthesis and characterization of polymers, as well as controlling their structures through modification, aims to develop novel recipes of biopolymer treatment with new application realms. The influences of biopolymer in many petroleum recovery cases were also evaluated to permit establishing the correlations between their physicochemical properties and performances. As their performance is heavily affected by the local environment, screening and testing polymers under controlled conditions is the necessary step to guarantee the efficiency and safety of biopolymer treatments.

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Recently emerging two-dimensional (2D) bismuth, bismuthene, has excited the world scientific community. It has been successfully synthesized to show high structural stability. Bismuthene possesses enhanced interaction with gas molecules due to its large surface area, which is a characteristic feature of 2D materials. This work performs a systematic firstprinciples study on the effects of the environmental gas molecules (CO, NO, NO 2 , H 2 , and NH 3 ) on the electronic structure and chemical activity of bismuthene. It is found that CO, NO, and NO 2 serve as charge acceptors. Furthermore, the adsorption of NO and NO 2 can produce noticeable modifications in the band structure of bismuthene. H 2 and NH 3 act as charge donors to bismuthene. Importantly, there is a large amount of transferred charge and a low adsorption energy of H 2 on bismuthene. Thereby, our study suggests bismuthene as a promising material for gas sensing applications and production of hydrogen storage devices.[a] Dr.