Facilitated magnesium atom adsorption and surface diffusion kinetics via artificial bismuth-based interphases

Porous Defective Bi/Bi3NbO7 Nanosheets for Efficient Photocatalytic NO Removal under Visible Light

Since conventional techniques are ineffective for NO removal at low concentrations, photocatalysis has become attractive in this regard, recently. However, in practice, photocatalytic NO removal has drawbacks such as limited light absorption and the proclivity of producing toxic by-products. To address these issues, novel defective Bi/Bi3NbO7 structures with good porosity were fabricated by a solvothermal method and used for enhanced photocatalytic NO removal under visible light irradiation. The morphological and structural properties of the prepared materials were comprehensively analyzed. The optimal photocatalytic activity of pore-defective Bi/Bi3NbO7 for NO removal was 60.3%, when the molar ratios of urea and Bi(NO)3•5H2O to pristine Bi3NbO7 were 1:25 and 1:2, respectively, under the following operational conditions: NO concentration of 700 ppb, catalyst dosage of 50 mg and irradiation time of 14 min. The induced defects and the surface plasmon resonance (SPR) effect of Bi nanodots made remarkable contributions to improving the photocatalytic NO removal as well as inhibiting the toxic byproduct NO2. The photocatalytic NO removal pathway over the prepared photocatalysts was further mechanistically clarified taking advantage of EPR results and scavenging experiments. Considering the increased NO generation in the atmosphere, this work may provide novel insights for designing effective porous photocatalysts to treat gaseous toxic pollutants.

Organic Electrolyte Design for Rechargeable Batteries: From Lithium to Magnesium

Rechargeable magnesium batteries (RMBs) have been considered as one of the most viable battery chemistries amongst the "post" lithium-ion battery (LIB) technologies owing to their high volumetric capacity and the natural abundance of their key elements. The fundamental properties of Mg-ion conducting electrolytes are of essence to regulate the overall performance of RMBs. In this Review, the basic electrochemistry of Mg-ion conducting electrolytes batteries is discussed and compared to that of the Li-ion conducting electrolytes, and a comprehensive overview of the development of different Mg-ion conducting electrolytes is provided. In addition, the remaining challenges and possible solutions for future research are intensively discussed. The present work is expected to give an impetus to inspire the discovery of key electrolytes and thereby improve the electrochemical performances of RMBs and other related emerging battery technologies.

Rechargeable Mg2+/Li+, Mg2+/Na+, and Mg2+/K+ Hybrid Batteries Based on Layered VS2

Rechargeable Mg batteries have great potential in next-generation scalable energy-storage applications, but the electrochemical performance is limited by the Mg-intercalation cathodes. Hybrid batteries based on dual-cation (Mg²⁺ and alkali metal cations) electrolytes would not only improve the electrochemical performance but also induce the co-intercalation of Mg²⁺ with alkali metal cations. As previous reports overwhelmingly focus on Mg²⁺/Li⁺ hybrid batteries, in this work, Mg²⁺/Na⁺ and Mg²⁺/K⁺ hybrid batteries are constructed using a typical layered VS₂ cathode and studied in comparison with Mg²⁺/Li⁺ batteries. It is observed that Mg²⁺ could co-intercalate into VS₂ with Li⁺, Na⁺, or K⁺. However, Mg-intercalation is irreversible in the Mg²⁺/Li⁺ system, and co-intercalation of Mg²⁺ and K⁺ would cause a collapse of VS₂. Comparatively, the co-intercalation of Mg²⁺ and Na⁺ into VS₂ exhibits the highest reversibility, and the Mg²⁺/Na⁺ hybrid battery shows the best cycling stability without capacity fading within 1000 cycles. Our work highlights the co-intercalation reversibility of a non-pre-expanded layered disulfide cathode and delivers insights for the development of high-performance rechargeable Mg metal batteries.

Current Design Strategies for Rechargeable Magnesium-Based Batteries

As a next-generation electrochemical energy storage technology, rechargeable magnesium (Mg)-based batteries have attracted wide attention because they possess a high volumetric energy density, low safety concern, and abundant sources in the earth's crust. While a few reviews have summarized and discussed the advances in both cathode and anode materials, a comprehensive and profound review focusing on the material design strategies that are both representative of and peculiar to the performance improvement of rechargeable Mg-based batteries is rare. In this mini-review, all nine of the material design strategies and approaches to improve Mg-ion storage properties of cathode materials have been comprehensively examined from both internal and external aspects. Material design concepts are especially highlighted, focusing on designing "soft" anion-based materials, intercalating solvated or complex ions, expanding the interlayer of layered cathode materials, doping heteroatoms into crystal lattice, size tailoring, designing metastable-phase materials, and developing organic materials. To achieve a better anode, strategies based on the artificial interlayer design, efficient electrolyte screening, and alternative anodes exploration are also accumulated and analyzed. The strategy advances toward Mg-S and Mg-Se batteries are summarized. The advantages and disadvantages of all-collected material design strategies and approaches are critically discussed from practical application perspectives. This mini-review is expected to provide a clear research clue on how to rationally improve the reliability and feasibility of rechargeable Mg-based batteries and give some insights for the future research of Mg-based batteries as well as other multivalent-ion battery chemistries.