Using photocatalysis for sustainable agriculture: R-leaf's potential in large-scale N2O mitigation

• The performance of R-Leaf in removing N2O in laboratory work is demonstrated. • The photocatalyst functions effectively under both UV and visible light, suggesting applicability in sunlight. • R-Leaf exhibited 50 % higher activity compared to TiO2, used as the control. • Air atmosphere experiments showed enhanced N2O removal, highlighting the beneficial role of O2 in photocatalyst performance. • Preliminary studies indicate R-Leaf's potential for decarbonizing agricultural fields. Addressing climate change through the removal of greenhouse gases (GHGs) is crucial for achieving global environmental goals. Nitrous oxide (N 2 O) has gained increasing attention due to its significant global warming potential—approximately 300 times that of CO 2 —and its rising atmospheric levels, largely driven by intensive agriculture. Among the various methods proposed for air pollutant removal, photocatalysis presents a promising and sustainable approach, especially if utilising solar light as an excitation source. This work investigates the photocatalytic removal of N₂O using R-Leaf, a TiO₂-based photocatalyst, under both controlled laboratory conditions and real-world field applications. In laboratory experiments conducted in a batch photoreactor R-Leaf achieved N₂O conversion rates between 6 % and 12 %, depending on initial concentrations and atmospheric conditions. Notably, in air, conversion efficiency increased, indicating a promising role for oxygen in enhancing photocatalytic activity. Finally, to demonstrate the potential of R-Leaf for applications in large agricultural areas, a small-scale field trial was performed. After application of the photocatalyst, approximately 1 ppbv of N 2 O was removed when compared with a nearby control field without the R-Leaf. While the observed change in N₂O concentration was relatively small, its impact is magnified by the vast scale of global agricultural land. These findings highlight R-Leaf's potential as a sustainable solution for decarbonizing agriculture, paving the way for large-scale photocatalytic air purification.