Through appropriate engineering of the 5,5′-bis(mercaptomethyl)-2,2′-bipyridine self-assembled monolayer (BPD-SAM) on a gold surface, ultrathin sulfur functionalized freestanding carbon–metal nanosheets (CMNS) have been produced. The BPD-SAM was used to encapsulate Ni⁺². The resulting BPD–Ni⁺² SAM was cross-linked by high-energy electrons. The nanomembrane was realized by dissolving the gold substrate. The chemical and physical properties of the CMNS were investigated using X-ray photoelectron spectroscopy (XPS), UV-vis reflection spectroscopy, atomic force microscopy (AFM), scanning electron microscopy (SEM), energy dispersive X-ray (EDX), and electrical two-point probe measurements.