The bandgaps of monolayer and bulk molybdenum sulfide (MoS2 ) result in that they are far from suitable for application as a saturable absorption device. In this paper, the operation of a broadband MoS2 saturable absorber is demonstrated by the introduction of suitable defects. It is believed that the results provide some inspiration in the investigation of two-dimensional optoelectronic materials.

Photodetectors with excellent detecting properties over a broad spectral range have advantages for the application in many optoelectronic devices. Introducing imperfections to the atomic lattices in semiconductors is a significant way for tuning the bandgap and achieving broadband response, but the imperfection may renovate their intrinsic properties far from the desire. Here, by controlling the deviation from the perfection of the atomic lattice, ultrabroadband multilayer MoS photodetectors are originally designed and realized with the detection range over 2000 nm from 445 nm (blue) to 2717 nm (mid-infrared). Associated with the narrow but nonzero bandgap and large photoresponsivity, the optimized deviation from the perfection of MoS samples is theoretically found and experimentally achieved aiming at the ultrabroadband photoresponse. By the photodetection characterization, the responsivity and detectivity of the present photodetectors are investigated in the wavelength range from 445 to 2717 nm with the maximum values of 50.7 mA W and 1.55 × 10 Jones, respectively, which represent the most broadband MoS photodetectors. Based on the easy manipulation, low cost, large scale, and broadband photoresponse, this present detector has significant potential for the applications in optoelectronics and electronics in the future.

Nanomaterials with intrinsic enzyme-like activities, namely "nanozymes," are showing increasing potential as a new type of broad-spectrum antibiotics. However, their feasibility is still far from satisfactory, due to their low catalytic activity, poor bacterial capturing capacity, and complicated material design. Herein, a facile synthesis of a defect-rich adhesive molybdenum disulfide (MoS 2)/rGO vertical heterostructure (VHS) through a one-step microwave-assisted hydrothermal method is reported. This simple, convenient but effective method for rapid material synthesis enables extremely uniform and well-dispersed MoS 2 /rGO VHS with abundant S and Mo vacancies and rough surface, for a performance approaching the requirements of practical application. It is demonstrated experimentally and theoretically that the as-prepared MoS 2 /rGO VHS possesses defect and irradiation dual-enhanced triple enzyme-like activities (oxidase, peroxidase, and catalase) for promoting free-radical generation, owing to much more active edge sites exposure. Meanwhile, the VHS-achieved rough surface exhibits excellent capacity for bacterial capture, with elevated reactive oxygen species (ROS) destruction through local topological interactions. As a result, optimized efficacy against drug-resistant Gram-negative and Gram-positive bacteria can be explored by such defect-rich adhesive nanozymes, demonstrating a simple but powerful way to engineered nanozymes for alternative antibiotics.

Spintronics holds the promise for future information technologies. Devices based on manipulation of spin are most likely to replace the current silicon complementary metal‐oxide semiconductor devices that are based on manipulation of charge. The challenge is to identify or design materials that can be used to generate, detect, and manipulate spin. Since the successful isolation of graphene and other two‐dimensional (2D) materials, there has been a strong focus on spintronics based on 2D materials due to their attractive properties, and much progress has been made, both theoretically and experimentally. Here, we summarize recent developments in spintronics based on 2D materials. We focus mainly on materials of truly 2D nature, that is, atomic crystal layers such as graphene, phosphorene, monolayer transition metal dichalcogenides, and others, but also highlight current research foci in heterostructures or interfaces. In particular, we emphasize roles played by computation based on first‐principles methods which has contributed significantly in the designs of spintronic materials and devices. We also highlight challenges and suggest possible directions for further studies. WIREs Comput Mol Sci 2017, 7:e1313. doi: 10.1002/wcms.1313 This article is categorized under: Structure and Mechanism > Computational Materials Science Electronic Structure Theory > Ab Initio Electronic Structure Methods Electronic Structure Theory > Density Functional Theory

Graphene was the first material predicted to realize a topological insulator (TI), but unfortunately the gap is unobservably small due to carbon's weak spin-orbital coupling (SOC). Based on first-principles calculations, we propose a stable sp-sp2 hybrid carbon network as a graphene analog whose electronic band structures in proximity of the Fermi level are characterized by Dirac cones. We demonstrate that this unique carbon framework has topologically nontrivial electronic structures with the Z2 topological invariant of v = 1 which is quite promising for hosting the quantum spin Hall effect (QSHE) in an experimentally accessible low temperature regime (<7 K). This provides a viable approach for searching for new TIs in 2D carbon allotropes.