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.