A dual-modification strategy for P2-type layered oxide via bulk Mg/Ti co-substitution and MgO surface coating for sodium ion batteries.

P2-type materials are regarded as competitive cathodes for next generation sodium ion batteries. However, the unfavorable P2 → O2 phase transition usually leads to severe capacity decay. Moreover, the cathode material always suffers from destruction of surface crystal structure caused by trace amount of HF.

Facile Synthesis of Nitrogen-Doped Green-Emission Carbon Dots as Fluorescent Off-On Probes for the Highly Selective Sensing Mercury and Iodine Ions.

In this work, green-emission carbon dots (CDs) were prepared for detecting mercury ions (Hg(II)) and iodine ions via a facile hydrothermal method using ethylenediamine and methyl red as nitrogen and carbon sources, respectively, without any other complex reagents. The bacteriostasis experiment showed that the CDs were not toxic to the growth of four kinds of bacteria: , which indicated that the CDs had good security and could be used for analysis and detection. The CDs exhibited excitation-independent emission, the fluorescence of which could be quenched by Hg(II), and could be recovered by iodine ions.