An assembly and self-template strategy is presented for the synthesis of cobalt phosphide nanoparticles (CoP_x, x = 1, 2) embedded into 3D phosphorus/nitrogen co-doped reticular porous carbon frameworks (denoted as CoP_x@P,N–RPCs) utilizing polyacrylonitrile (PAN) as the in situ nitrogen doping carbon source and hypophosphite as phosphorus source via hydrothermal method and subsequent phosphorization. The obtained CoP_x@P,N–RPCs nanocomposite possesses the inherent features of both unique 3D porous structure and hierarchical connectivity, providing highly efficient pathways for electron, ion, and mass transport. The unique P,N co-doped carbon network confines nanostructural CoP_x into the microstructural carbon network, which prevents them from aggregating, improves the conductivity of CoP_x, meanwhile alleviates large volume expansion/contraction effect, thus results in high electrochemical performance and cycling durability. Benefiting from its unique structural advantages, the CoP_x@P,N–RPCs nanocomposite exhibits excellent electrochemical performance for nitrite (NO₂–) detection with a wide linear range of 10 nM to 1.184 mM, a low detection limit of 5 nM, and a very high stability, which is better than most nitrite sensors reported previously. Importantly, the nitrite level can be determined by the resulting sensor in food and drinking water with excellent recoveries, implying its feasibility for realistic application.

提出了一种组装和自模板化策略，用于合成嵌入3D磷/氮共掺杂网状多孔碳骨架（表示为CoP _x @ P，N–RPCs ）的磷化钴纳米粒子（CoP _x，x = 1，2））通过水热法并随后进行磷化，利用聚丙烯腈（PAN）作为原位氮掺杂碳源和次磷酸盐作为磷源。获得的CoP _x @ P，N–RPCs纳米复合材料具有独特的3D多孔结构和分层连接性的固有特征，为电子，离子和质量传输提供了高效途径。独特的P，N共掺杂碳网络限制了纳米结构CoP _x进入微结构碳网络，防止它们的聚集，提高了CoP _x的电导率，同时减轻了大体积的膨胀/收缩作用，因此具有较高的电化学性能和循环耐久性。得益于其独特的结构优势，CoP _x @ P，N–RPCs纳米复合材料对亚硝酸盐（NO ₂ –）的检测具有出色的电化学性能，线性范围为10 nM至1.184 mM，检测限低至5 nM，并且具有很高的稳定性，比以前报道的大多数亚硝酸盐传感器要好。重要的是，亚硝酸盐含量可以通过食品和饮用水中的传感器确定，回收率极高，这暗示了其在实际应用中的可行性。