Diamond and silicon carbide synthesis by direct CO2 capture in open air rapidly solidified Al (11wt.%Cu)

Using high-frequency induction fusion and rapid solidification under atmospheric pressure, we synthesized an Al–11 wt.% Cu alloy at ~ 800 °C for 30 min. A bimodal microstructure of silicon carbide (SiC) and diamond particles was observed, despite the absence of silicon or carbon in the initial melt. We hypothesize that carbon originated from atmospheric CO₂ absorbed during melting, while silicon likely derived from aluminum via in-situ transformation. This CO₂-induced carbonization led to the formation of SiC within the aluminum matrix, significantly enhancing the alloy’s mechanical and wear-resistant properties. Unlike conventional methods that introduce diamond externally, our process enables in-situ diamond and SiC formation during melting, offering a novel, sustainable pathway for CO₂ utilization. This approach not only improves material performance but also contributes to carbon capture and conversion at ambient pressure.