Microporous polycarbazole via straightforward carbazole-based oxidative coupling polymerization is reported. The synthesis route exhibits cost-effective advantages, which are essential for scale-up preparation. The Brunauer-Emmett-Teller specific surface area for obtained polymer is up to 2220 m(2) g(-1). Gas (H(2) and CO(2)) adsorption isotherms show that its hydrogen storage can reach to 2.80 wt % (1.0 bar and 77 K) and the uptake capacity for carbon dioxide is up to 21.2 wt % (1.0 bar and 273 K), which show a promising potential for clean energy application and environmental field. Furthermore, the high selectivity toward CO(2) over N(2) and CH(4) makes the obtained polymer possess potential application in gas separation.

A molten salt system is developed for low-temperature metallothermic reduction of various silicates or silica to crystalline Si nanoparticles as high-performance anode materials.

The low capacity and unsatisfactory rate capability of hard carbon still restricts its practical application for Li/K‐ion batteries. Herein, a low‐cost and large‐scale method is developed to fabricate phosphorus‐doped hard carbon (PHC‐700) by crosslinking phosphoric acid and epoxy resin and followed by annealing at 700 °C. H3PO4 acts not only as a crosslinker to solidify epoxy resin for promoting the degree of graphitization and lowering the specific surface area, but also as phosphorus source for forming PC and PO bonds, thus providing more active sites for Li/K storage. As a result, the PHC‐700 electrode delivers a highly reversible capacity of 1294.8 mA h g−1 at 0.1 A g−1 and a capacity of 214 mA h g−1 after 10 000 cycles at 10 A g−1. As for potassium‐ion batteries, PHC‐700 exhibits a reversible capacity of 381.9 mA h g−1 at 0.1 A g−1 and a capacity of 260 mA h g−1 after 1000 cycles at 0.2 A g−1. In situ Raman and in situ NMR measurements reveal that the P‐containing bonds can enhance the adsorption to alkali metal ions, and the PC bond can participate in electrochemical redox reaction by forming Lix PCy . Additionally, P‐doped hard carbon shows better structural/interfacial stability for improved long‐term cycling stability.