With high theoretical energy density, rechargeable metal–gas batteries (e.g., Li–CO2 battery) are considered as one of the most promising energy storage devices. However, their practical applications are hindered by the sluggish reaction kinetics and discharge product accumulation during battery cycling. Currently, the solutions focus on exploration of new catalysts while the thorough understanding of their underlying mechanisms is often ignored. Herein, the interfacial electronic interaction within rationally designed catalysts, ZnS quantum dots/nitrogen‐doped reduced graphene oxide (ZnS QDs/N‐rGO) heterostructures, and their effects on transformation and deposition of discharge products in the Li–CO2 battery are revealed. In this work, the interfacial interaction can both enhance the catalytic activities of ZnS QDs/N‐rGO heterostructures and induce the nucleation of discharge products to form a homogeneous Li2CO3/C film with excellent electronic transmission and high electrochemical activities. When the batteries cycle within a cutoff specific capacity of 1000 mAh g−1 at a current density of 400 mA g−1, the cycling performance of the Li–CO2 battery using a ZnS QDs/N‐rGO cathode is over 3 and 9 times than those coupled with a ZnS nanosheets (NST)/N‐rGO cathode and a N‐rGO cathode, respectively. This work provides comprehensive understandings on designing catalysts for Li–CO2 batteries as well as other rechargeable metal–gas batteries.

The hydrogen-rich superconductors stabilized at high-pressure conditions have been the subject of topic interests. There is an essential hope that hydrogen-rich superconductors are promising candidates of room-temperature superconductors. Recent advances in first-principles crystal structure prediction techniques have opened up the possibility of reliable prediction of superconductive structures, and subsequent superconductivity calculations based on phonon-mediated superconducting mechanism revealed a general appearance of high temperature superconductivity in pressurized hydrides. Theory-orientated experiments at high pressure discovered a number of hydrogen-rich superconductors, among which sulfur hydrides exhibit a remarkably high superconducting critical temperature reaching 203 K. In this review, we discuss the emerging research activities towards hydrogen-rich superconductors at high pressures and outlook the future direction in the field.

A series of double-chain quaternary ammonium salt surfactants N-[N′[3-(gluconamide)] propyl-N′-alkyl]propyl-N, N-dimethyl-N-alkyl ammonium bromide (CnDDGPB, where n represents a hydrocarbon chain length of 8, 10, 12, 14 and 16) were successfully synthesized from D (+)-glucose δ-lactone, N, N-dimethyldipropylenetriamine, and bromoalkane using a two-step method consisting of a proamine-ester reaction and postquaternization. Their surface activity, adsorption, and aggregation behavior in aqueous solution were investigated via measurements of dynamic/static surface tension, contact angle, dynamic light scattering, and transmission electron microscopy. An analysis of their application performance in terms of wettability, emulsifying properties, toxicity, and antibacterial properties was conducted. The results show that with increasing the carbon chain length of the CnDDGPB surfactants, their critical micelle concentration (CMC) increased and the pC20 and efficiency in the interface adsorption of the target product gradually decreased. Moreover, the influence of the hydrophobic carbon chain length on the surface of polytetrafluoroethylene (PTFE) was even greater for the wetting effect, reducing the contact angle to 32° within the length range of C8–C14. The results of the contact angle change and the wettability experiments proved that C10DDGPB exhibited the best wettability. The liquid paraffin and soybean oil emulsification ability of CnDDGPB showed an upward trend followed by a downward trend with the growth of the carbon chain, with C12DDGPB exhibiting the best emulsification performance. The Dlong/Dshort ratio was far lower than 1, which indicates mixed-kinetic adsorption. The surfactants formed spherical micelles and showed a unique aggregation behavior in aqueous solution, which showed an increase–decrease–increase trend with the change in concentration. A cell toxicity and acute oral toxicity experiment showed that the CnDDGPB surfactants were less toxic than the commonly used surfactant dodecyldimethylbenzyl ammonium chloride (1227). In addition, at a concentration of 150 ppm, CnDDGPB exhibited the same bacteriostatic effect as 1227 at a concentration of 100 ppm. The results demonstrate that sugar-based amide cationic surfactants are promising as environmentally friendly disinfection products.

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In this paper, 1 μm n-GaN was grown by using varied and fixed ammonia flow (NH 3 ) on SiN x mask layer on Si(111) substrate using metal organic chemical vapor deposition (MOCVD). In-situ optical reflectivity traces of GaN growth show that the three-to two-dimensional process has been prolonged by using varied ammonia flow on SiN x mask layer method compared with that grown by fixing ammonia flow. Structural and optical properties were characterized by high-resolution X-ray diffraction and photoluminescence, and compared with the sample grown by fixing ammonia flow, GaN grown using the varied ammonia flow on SiN x mask layer showed better structure and optical quality. It was assumed that the low NH 3 flow in the initial growth stage considerably increased the GaN island density on the nano-porous SiN x layer by enhancing vertical growth. Lateral growth was significantly favored by high NH 3 flow in the subsequent step. As a result, the improved crystal and optical quality was achieved utilizing NH 3 flow modulation for GaN buffer growth on Si(111) substrate.

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