Large-Scale Synthesis of Multifunctional Single-Phase Co 2 C Nanomaterials.

Achieving scalable synthesis of nanoscale transition-metal carbides (TMCs), regarded as substitutes for platinum-group noble metals, remains an ongoing challenge. Herein, a 100-g scale synthesis of single-phased cobalt carbide (Co 2 C) through carburization of Co-based Prussian Blue Analog (Co-PBA) is reported in CO 2 /H 2 atmosphere under mild conditions (230 °C, ambient pressure). Textural property investigations indicate a successful preparation of orthorhombic-phased Co 2 C nanomaterials with Pt-group-like electronic properties. As a demonstration, Co 2 C achieves landmark photo-assisted thermal catalytic CO 2 conversion rates with photo-switched product selectivity, which far exceeds the representative Pt-group-metal-based catalysts. This impressive result is attributed to the excellent activation of reactants, colorific light absorption, and photo-to-thermal conversion capacities. In addition to CO 2 hydrogenation, the versatile Co 2 C materials show huge prospects in antibacterial therapy, interfacial water evaporation, electrochemical hydrogen evolution reaction, and battery technologies. This study paves the way toward unlocking the potential of multi-functional Co 2 C nanomaterials.