Nanozymes are next-generation of nanomaterials with enzyme-like activities. In particular, nanozymes with peroxidase (POD)-like activity have been utilized in various fields, including antibacterial, detection, degradation, etc. However, their extensive applications were limited by their low catalytic activity currently. Herein, we have presented a composite nanozyme based on attapulgite (ATP) (Fe-ATP-MoS₂ (FAM)), which exhibited enhanced POD-like activity (185.33 U·mg⁻¹), 4.25 times higher than that of Fe-MoS₂ (FM) (43.63 U·mg⁻¹). The density functional theory (DFT) calculations indicated that the addition of ATP increased the electron density of metal centers (Mo and Fe). More importantly, Michaelis–Menten kinetics revealed that the introduction of ATP significantly enhanced the binding affinities of substrates through the pores of ATP, forming a highly concentrated substrate microenvironment and thus promoting its POD-like activity. Additionally, from molecular size and kinetic analysis, we proposed that the changes in substrate size before and after oxidation also significantly affected its Michaelis-constant (K_m) value. Furthermore, we utilized FAM in the applications of highly effective antibacterial application and sensitive detection of glutathione (GSH). In conclusion, this work provides a novel approach for designing a highly efficient nanozyme based on natural mineral composites.

It is the sluggish ion migration kinetics that seriously affects the practical performance of the magnesium ion batteries. Even though an electrode material design using rational interlayer engineering method could effectively solve this issue, the optimal interlayer distance remains undetermined. Herein, various VOPO₄-based electrodes with expanded interlayer spacing were fabricated and the relationship between interlayer structure and battery performance was revealed. Electrochemical analysis combined with computations unveils the existence of an optimal interlayer structure, as inadequate expansion failed to fully utilization of the material performance, while excessive expansion degraded the electrode stability. Among them, the electrode with triethylene glycol (TEG) intercalation exhibited optimized performance, maintaining excellent cycling stability (191.3 mAh·g⁻¹ after 800 cycles). Density functional theory (DFT) demonstrated the effectiveness and limitations to lowering the migration energy barrier by expanding the interlayer engineering. In addition, systematic mechanism research revealed the Mg²⁺ storage process: The stepwise shuttling of Mg²⁺ along the directions that lie in (001) plane triggers two pairs of redox processes, namely V⁵⁺/V⁴⁺ and V⁴⁺/V³⁺. This study, regulation of layer spacing to achieve the best integrated performance of electrodes, could deepen the understanding of interlayer engineering and guide the design of advanced multivalent-ion batteries.

Transition metal phosphides (TMPs) have been widely studied as electrode materials for supercapacitors and lithium-ion batteries due to their high electrochemical reaction activities. The practical application of TMPs was generally hampered by their low conductivity and large volume changes during electrochemical reactions. In this work, nitrogen-doped-carbon (NC) coated Ni₂P-Ni hybrid sheets were fabricated and loaded into highly conductive graphene network, forming a Ni₂P-Ni@NC@G composite. The highly conductive graphene, the NC coating layer, and the decorated Ni nanoparticles in combination offer continuous electron transport channels in the composite, resulting with facilitated electrode reaction kinetics and superior rate performance. Besides, the flexible graphene sheets and well-decorated Ni particles among Ni₂P can effectively buffer the harmful stress during electrochemical reactions to maintain an integrated electrode structure. With these favorable features, the composite demonstrated superior capacitive and lithium storage behavior. As an electrode material for supercapacitors, the composite shows a remarkable capacitance of 2, 335.5 F·g^-1 at 1 A·g^-1 and high capacitance retention of 86.4% after 2, 000 cycles. Asymmetrical supercapacitors (ASCs) were also prepared with remarkable energy density of 53.125 Whk·g^-1 and power density of 3, 750 Whk·g^-1. As an anode for lithium ion batteries, a high reversible capacity of 1, 410 mAh·g^-1 can be delivered at 0.2 A·g^-1 after 200 cycles. Promising high rate capability was also demonstrated with a high discharge capacity of 750 mAh·g^-1 at 8 A·g^-1. This work shall pave the way for the production of other TMP materials for energy storage systems.

Red phosphorus-carbon nanotube (P@CNT) composites were synthesized as anodes for advanced lithium ion batteries via a facile solution-based method at room temperature. In these composites, the entangled P@CNT nanostructure reduced the aggregation of both components and allowed their complete utilization in a synergetic manner. The highly conductive and porous CNT framework, along with the nanoscale red P particles intimately anchored on the CNT surface, conferred the composite with excellent ion/electron transport properties. Volume expansion within the red P particles was mitigated by their amorphous and nanoscale features, which can be well buffered by the soft CNTs, therefore maintaining an integrated electrode structure during cycling. When used as an anode in lithium ion batteries, the composite exhibited a reversible capacity of 960 mAh·g^-1 (based on the overall weight of the composite) after 120 cycles at 200 mA·g^-1. The composite also delivered excellent high-rate capability with capacities of 886, 847, and 784 mAh·g^-1 at current densities of 2, 000, 4, 000, and 10, 000 mA·g^-1, respectively, which reveals its potential as a high performance anode for lithium ion batteries.

An asymmetrical supercapacitor (ASC), comprising reduced graphene oxide (rGO)-encapsulated nickel phosphite hollow microspheres (NPOH-0.5@rGO) as positive electrode, and porous nitrogen/sulfur co-doped rGO aerogel (NS-3D rGO) as negative electrode has been prepared. The NPOH-0.5@rGO electrode combines the advantages of the NPOH hollow microspheres and the conductive rGO layers giving rise to a large specific capacitance, high cycling reversibility, and excellent rate performance. The NS-3D rGO electrode with abundant porosity and active sites promotes electrolyte infiltration and broadens the working voltage range. The ASC (NPOH-0.5@rGO//NS-3D rGO) shows a maximum voltage of up to 1.4 V, outstanding cycling ability (capacitance retention of 95.5% after 10, 000 cycles), and excellent rate capability (capacitance retention of 77% as the current density is increased ten times). The ASC can light up an light-emitting diodes (LED) for more than 20 min after charging for 20 s. The fabrication technique and device architecture can be extended to other active oxide and carbon-based materials for next-generation high-performance electrochemical storage devices.