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

[Display omitted] •CuFe2O4 catalyst with (111) dominant facet was prepared by KNO3 as capping agent.•(111) facet has lower hydrolytic ionization barrier and suitable *H binding strength.•Performance of the electrode was further improved by making into 3D printed electrode.•The 3D printed electrode has more exposed active sites and fewer phase interfaces.•3D (111) CuFe2O4 electrode is only 160 mV at 100 mA cm−2, Tafel slope is 33 mV dec-1. 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 KNO3 as a capping agent, the exposed crystal facet of CuFe2O4 is regulated, and the crystal facet (111) becomes dominant. Compared to CuFe2O4 (3 1 1), CuFe2O4 (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 CuFe2O4 (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 CuFe2O4 (111) electrodes shows high stability. The superior performance of 3D printed CuFe2O4 (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.