3D printed CuFe2O4 electrode with dominant facet (111) for boosting hydrogen evolution performance

The utilization of hydrogen energy is an important way to low carbon economy, and the development of active electrodes is the most critical step for efficient hydrogen evolution reaction. With the addition of KNO 3 as a capping agent, the exposed crystal facet of CuFe 2 O 4 is regulated, and the crystal facet (111) becomes dominant. Compared to CuFe 2 O 4 (3 1 1), CuFe 2 O 4 (111) exhibits low barrier of water dissociation and suitable *H binding strength, resulting in high intrinsic activity. Furthermore, the 3D printed electrodes show more excellent performance. At 3D printed CuFe 2 O 4 (111) electrode, the overpotential is only 152 mV (vs. reversible hydrogen electrode) at 100 mA cm −2 , and Tafel slope is as low as 33 mV dec -1 . In addition, 3D printed CuFe 2 O 4 (111) electrodes shows high stability. The superior performance of 3D printed CuFe 2 O 4 (111) electrodes originates from high intrinsic activity and more exposed active sites. This study provides a new path for the development of efficient, stable and inexpensive monolithic catalyst electrodes for alkaline hydrogen evolution.