Synergistic effect of interface and defect engineering of MoC/MoO₂ nano dot encapsulated N-doped carbon nanoflowers for highly durable dye-sensitized solar cells

The design and fabrication of advanced counter electrodes (CEs) for dye-sensitized solar cells (DSSCs) are limited by the scarcity of active sites and poor durability. Herein, we report the controlled preparation of a heterostructured nanoreactor CE based on defect-rich N-doped carbon nanoflowers (NCF) encapsulating MoC/MoO2 nano dots (NDs) in a well-defined heterophase (MoC/MoO2-NCF). The MoC/MoO2 NDs were uniformly dispersed on the NCF, and the NCF limited the size of the MoC/MoO2 NDs and prevented their agglomeration, thus maximizing the electrochemically active surface area of MoC/MoO2. Moreover, the synergistic effect between the MoC/MoO2 interface and the N-defects is conducive to the full exposure of the active sites. Furthermore, theoretical calculations revealed that the MoC/MoO2 heterojunction played a unique role in modulating the