The performance of water purification by adsorption method has been limited owing to the fact that most of current available adsorbents fail to achieve satisfactory removal performance for organic micropollutants. Herein, we report the design and synthesis of novel porous polymeric adsorbent built from β-cyclodextrin (β-CD), in which β-CD molecules are arranged in an ordered bis (β-CD) tubular assemblies. The induction of bis (β-CD) units renders them high adsorption affinity toward bisphenols (bisphenol A and its analogues bisphenol B, bisphenol F and bisphenol S), the typical endocrine disruptors, via the formation of stable host-guest inclusion complexes in aquatic systems. In combination with their high porosity (Brunauer-Emmett-Teller (BET) surface area of 150 m²·g^-1), abundant β-CD content and fast sorption kinetics, the obtained adsorbent outperforms commercial water purifier in elimination of bisphenol micropollutants from potable water. Our work may open a new avenue for designing highly efficient adsorbents for removal of organic micropollutants from aquatic systems.

Accelerating the rate-limiting oxygen reduction reaction (ORR) at the cathode remains the foremost issue for the commercialization of fuel cells. Transition metal–nitrogen–carbon (M–N/C, M = Fe, Co, etc.) nanostructures are the most promising class of non-precious metal catalysts (NPMCs) with satisfactory activities and stabilities in practical fuel cell applications. However, the long-debated nature of the active sites and the elusive structure-performance correlation impede further developments of M–N/C materials. In this review, we present recent endeavors to elucidate the actual structures of active sites by adopting a variety of physicochemical techniques that may provide a profound mechanistic understanding of M–N/C catalysts. Then, we focus on the spectacular progress in structural optimization strategies for M–N/C materials with tailored precursor architectures and modified synthetic routes for controlling the structural uniformity and maximizing the number of active sites in catalytic materials. The recognition of the right active centers and site-specific engineering of the nanostructures provides future directions for designing advantageous M–N/C catalysts.