Light-Mediated Enhancement of Carbon Sequestration in Engineered Spathiphyllum

Carbon sequestration is essential to mitigate climate change and atmospheric carbon dioxide levels. Utilizing indoor plants, such as Spathiphyllum (Peace Lily), is desirable for sustainable living, thanks to their carbon sequestration characteristics and ability to remove air toxins and adjust humidity. In this study, a luminescent energy storage material, calcium sulfide doped with europium and dysprosium (CaS:Eu,Dy) phosphor, was synthesized and applied to the surface of Spathiphyllum (Peace Lily) leaves to improve its photosynthetic efficiency and carbon sink potential. This phosphor absorbs incident visible light and converts short-wavelength light to long-wavelength light. When excited by 514 nm light, the CaS:Eu,Dy phosphor emits a red light at 652 nm. Additionally, CaS:0.5%Eu,0.25%Dy has the best luminescence duration compared to other dopants, with a relaxation time of 2.392 s. To prevent the phosphor from hygroscopic degradation in the air, a SiO₂ coating was applied to the material's surface, increasing the phosphor's lifespan and preventing environmental damage. Based on the chlorophyll fluorescence induction OJIP curve, it was observed that using the phosphor on the leaves of Peace Lily does not affect the plant's physiological condition, and the plant remains healthy. Furthermore, compared to untreated leaves, the photosynthetic efficiency of treated Peace Lily leaves could increase by 42%, resulting in an additional carbon sequestration of about 0.045 mol of CO₂ per square meter of leaves per day. This also allows the Peace Lily to emit red light in the dark, thereby enhancing its ornamental value as an indoor plant.