Rechargeable magnesium-ion batteries (RMBs) are considered promising energy storage devices due to their high energy density, low-cost, and reliable safety. However, their development is still constrained by problems such as sluggish Mg²⁺ diffusion kinetics and poor structural stability. Herein, an urchin-like VS₄@Bi₂S₃ heterostructure cathode with moderate sulfur vacancy concentration and well-defined heterointerfaces has been successfully constructed through in-situ growing Bi₂S₃ nanorods on VS₄ microspheres via rapid (25 min) microwave-assisted solvothermal method. The appropriate sulfur vacancies provide abundant active sites while mitigating structural degradation caused by excessive defects. Besides, the material forms a Type-II heterojunction via V-S-Bi interfacial chemical bridging, inducing a built-in electric field that significantly enhances electron transport, facilitates Mg²⁺ adsorption (−1.90 eV) and diffusion (energy barrier of 0.47 eV), and buffers volume changes during cycling. Electrochemical evaluations demonstrate that the optimized VS₄@Bi₂S₃ electrode delivers an initial discharge capacity of 1407.69 mAh·g⁻¹ and stabilized at about 353.50 mAh·g⁻¹ at 0.05 A·g⁻¹, which is significantly higher than that of VS₄ (227.31 mAh·g⁻¹) and Bi₂S₃ (152.29 mAh·g⁻¹). A combination of ex-situ/in-situ characterization and theoretical simulations reveals the synergistic magnesium storage mechanism involving intercalation and nanoconfined conversion reactions, along with interfacial dynamic stabilization. This work offers new insights into rational material design and mechanistic understanding for developing high energy density and long-life RMBs.

Covalent triazine frameworks (CTFs) are a class of unique two-dimensional nitrogen-rich triazine framework with adjustable chemical and electronic structures, rich porosity, good stability and excellent semiconductivity, which enable great various applications in efficient gas/molecular adsorption and separation, energy storage and conversion, especially photo- and electro-catalysis. Different synthesis strategies strongly affect the morphology of CTFs and play an important role in their structure and properties. In this concept, we provide a comprehensive and systematic review of the synthesis methods such as ionothermal synthesis, phosphorus pentoxide catalytic method, polycondensation and ultra-strong acid catalyzed method, and applications of CTFs in photo- and electro-catalysis. Finally we offer some insights into the future development progress of CTFs materials for catalytic applications.