Metal-Organophosphine Framework-Derived N,P-Codoped Carbon-Confined Cu3P Nanopaticles for Superb Na-Ion Storage

Metal-organic framework derived approaches are emerging as a viable way to design carbon-confined transitional metal phosphides (TMPs@C) for energy storage and conversion. However, their preparation generally involves a phosphorization using a large amount of additional P sources, which inevitably releases flammable, poisonous PH3. Therefore, developing an efficient strategy for eco-friendly synthesis of TMPs@C is full of challenges. Here, a metal-organophosphine framework (MOPF) derived strategy is developed to allow an eco-friendly design of TMPs@C without an additional P source, avoiding release of PH3. To illustrate this strategy, 1,3,5-triaza-7-phosphaadamantane (PTA) ligands and Cu(NO3)(2) metal centers are employed to construct Cu/PTA-MOPFs nanosheets. Cu/PTA-MOPFs can be directly converted to carbon-confined Cu3P nanoparticles by annealing. Benefiting from high heteroatom content in PTA, a high doping content of 3.92 at% N and 8.26 at% P can also be achieved in the carbon matrix. As a proof-of-concept application, N,P-codoped carbon-confined Cu3P nanoparticles as anodes for Na-ion storage exhibit a high initial reversible capacity of 332 mA h g(-1) at 50 mA g(-1), and superb rate and cyclic performance. Due to rich coordination modes of organophosphine, MOPFs are expected to become a promising molecular platform for design of various heteroatom-doped TMPs@C for energy storage and conversion.