Photochemical Enhancement in Catalytic Activity of Nickel Nanoparticles for Hydration of CO2

The aqueous route for mineralization of CO2 is considered one of the least energy consuming processes for carbon capture and storage. Reversible hydration of CO2 is one of the slowest steps in the mineralization process, however, it can be enhanced using nickel nanoparticles (NiNPs). In this study we evaluate the influence of photochemical effects on the catalytic activity of NiNPs for hydration of CO2 by comparing pH change profiles of catalysed and uncatalysed reactions under different solar irradiation conditions. The activity of NiNPs for CO2 hydration is observed under artificial solar radiation, with and without an infrared (IR) filter and in dark conditions. It is found that the rate of CO2 hydration is enhanced by ∼16 % in the presence of IR‐filtered solar radiation and by ∼24 % with the presence of IR radiation. The enhancement of activity is attributed to absorption associated with the NiNP surface plasmon resonance at 400 nm. Nickel is a catalyst for hydration of CO2 leading to mineralization. NiNPs show photocatalytic enhancement for the same reaction. The photocatalytic enhancement is greater with solar irradiation including infrared light. Dissociation of water on the NiNP surface is the rate limiting step in hydration of CO2.