Oxidative Print Light Synthesis Thin Film Deposition of Prussian Blue

Prussian blue (PB) and Prussian blue analogues (PBAs) are commonly synthesized by conventional methods, such as chemical precipitation, thermal decomposition, and electrochemical deposition. Herein, we have successfully synthesized Prussian blue by oxidative print light synthesis (PLS) with a cubic Fe4[Fe(CN)6]3 phase, as confirmed by XRD compared to pure Prussian blue. Furthermore, UV−vis, FT-IR, Raman, and XPS measurements also present experimental evidence of PB formation from the Potassium hexacyanoferrate(II) trihydrate precursor by PLS. STEM images display aggregated PB particles of ca. 500 nm with a homogeneous distribution of Fe, N, C, and K throughout the sample. The electrochemical characterization provides excellent electrocatalytic performances during the charge and discharge processes, with oxidation/reduction reactions of high- and low-spin iron, which is already known as the interconversion of Prussian white to Prussian blue (PW ⇄ PB) and Prussian blue to Prussian green (PB ⇄ PG), respectively. In particular, PLS has been successfully employed as a smart and low-cost protocol to synthesize thin Prussian blue films, and possibly other PBAs, for applications in energy storage devices such as K, Na, and Mg ion batteries.