grown as the white laser gains [12][13][14][15] and some approaches have been developed for constructing the prerequisite optical feedback "cavity" with the goal of simultaneous RGB or RYGB lasing. [10,11,13,14] However, constrained by the compactness, difficulty in growth or wavelength control, or the environment friendly, the white lasers are still underdeveloped, and the available materials and approaches are still being extensively sought.In recent years, an emerging family of 2D nanomaterials, group of early transition metal carbides and/or carbonitrides labeled MXenes, was developed by selectively etching MAX phases, [16,17] where M represents an early transition metal, A denotes a main group of 3 or 4 elements, and X is either carbon or nitrogen. They have exhibited super chemical, physical, and environmental properties distinguishing from traditional 2D materials, e.g., they possess hydrophilic surface with metallic conductivity, excellent chemical stability, superior electrical conductivity, environmentally friendly characteristics, etc. [18][19][20][21][22] Unfortunately, their intrinsic photoluminescence response is low, which limits their optical and even further biological applications. The formation of quantum dots (QDs) would generally enhance their photoluminescence by means of the quantum confinement and edge effects, which has been recently experimentally realized in Ti 3 C 2 MXene QDs with the wavelength range from about 350 nm (violet) to 600 nm (orange-red). [23,24] Therefore, it can be believed that the 2D MXenes should be excellent white laser gain medium if the gain can be further enhanced especially in the red range and a broadband optical feedback "cavity" can be constructed. Associated with the theory of a finite atomic system, the sensitivity of the electronic states density of the QDs, corresponding to their photoluminescence, is dependent on their sizes due to the Coulomb blockade effect, [25][26][27] which indicated that the MXene quantum systems with fewer atom layers structure should be more susceptible to the same external passivation and should have better passivation effect than those MXenes with more atom layers structure. For MXene materials, their unique structural characteristics determine that they have at least three-atom layered structure, which indicates that the V 2 C MQDs with fewest atom layers should possess enhanced and broadened photoluminescence after passivation. Considering the optical feedback, effective Multicolor photoluminescence over the full visible color spectrum is critical in many modern science and techniques, such as full-color lighting, displays, biological and chemical monitoring, multiband communication, etc., but the ultimate white lasing especially on the nanoscale is still a challenge due to its exacting requirements in the balance of the gain and optical feedback at different wavelengths. Recently, 2D transition metal carbides (MXenes) have emerged, with some superior chemical, physical, and environmental properties distinguishing them from tr...

Nanocatalysts based on Fenton or Fenton‐like reactions for amplification of intracellular oxidative stress has become a frontier research area of tumor precise therapy. However, the major translational challenges are low catalytic efficiency, poor biocompatibility, and even potential toxicities. Here, a Ti‐based material with excellent biocompatibility is proposed for cancer treatment. The nonoxidized MXene‐Ti3C2Tx quantum dots (NMQDs‐Ti3C2Tx) are successfully prepared by a self‐designed microexplosion method. Surprisingly, it has an apparent inhibitory and killing effect on cancer cells, and excellent biocompatibility with normal cells. Moreover, the suppression rate of NMQDs‐Ti3C2Tx on xenograft tumor models can reach 91.9% without damaging normal tissues. Mechanistically, the Ti3+ of NMQDs‐Ti3C2Tx can react with H2O2 in the tumor microenvironment and high‐efficiently produce excessive toxic hydroxyl radicals to increase tumor microvascular permeability to synergistically kill cancer cells. This work should pave the way for tumor catalytic therapy applications of Ti‐based material as a promising and safer route.

The so-called graphane is a fully hydrogenated form of graphene. Because it is fully hydrogenated, graphane is expected to have a wide bandgap and is theoretically an electrical insulator. The transition from graphene to graphane is that of an electrical conductor, to a semiconductor, and ultimately to an electrical insulator. This unique characteristic of graphane has recently gained both academic and industrial interest. Towards the end of developing novel applications of this important class of nanoscale material, computational modeling work has been carried out by a number of theoreticians to predict the structures and electronic properties of graphane. At the same time, experimental evidence has emerged to support the proposed structure of graphane. This review article covers the important aspects of graphane including its theoretically predicted structures, properties, fabrication methods, as well as its potential applications.

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Overall population exposure is measured by multiplying the annual average number of extremely hot days by the number of people exposed to the resultant heat. Extreme heat is also subdivided into high temperature (HT) and extremely high temperature (EHT) in cases where daily maximum temperature exceeds 35℃ and 40℃, respectively. Chinese population exposure to HT and EHT over four periods in the future (i.e.

Aims We evaluated the efficacy of biochar application for suppressing bacterial wilt of tomato and identified the potential underlying mechanisms involved in the disease control. Methods We measured the impact of two different sized biochar (53-120 μm and 380-830 μm) on bacterial wilt incidence in a greenhouse experiment. The efficiency of different sized biochar for the adsorption of tomato root exudates and the pathogen was further examined in vitro. We also quantified the effects of biochar and tomato root exudates on two pathogen virulence factors, chemotaxis, swarming motility and examined the effect of biochar on pathogen root colonization.Results Fine biochar application (3%; w:w) significantly decreased the bacterial wilt incidence by 19.9%. Biochar with different particle size had similar adsorption capacity for root exudates, while fine biochar was efficient (91%) in pathogen adsorption. Root exudates and fine biochar increased the chemotaxis ability of pathogen, while fine biochar reduced pathogen swarming motility and rhizosphere colonization. Conclusions Application of fine biochar can significantly decreased bacterial wilt incidence. This was mechanistically explained by biochar ability to 1) adsorb pathogen directly and indirectly via adsorption of root exudates (based on pathogen chemotaxis) and to 2)

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