X-ray induced synthesis of a novel material: Stable, doped solid CO at ambient conditions

•Synthesis of a novel material: doped polymeric CO via hard X-ray photochemistry:SrC2O4+hυ→SrCO3+polyCO.•The reaction occurs at ambient conditions and at elevated pressure.•The material is very stable and trapped CO2 inside it at ambient conditions for over one year.•Potential optical and electrical benefits of industrial/technological importance.