Hydrogen evolution reactions using 3D printed composites of copper with graphene and hexagonal boron nitride

The design of scalable, efficient electrocatalysts is essential for green hydrogen production. Here, we employed direct ink writing (DIW) 3D printing to fabricate Cu-based composites with graphene (Gr) and hexagonal boron nitride (h-BN), utilizing precise porosity control and interface engineering for enhanced hydrogen evolution reaction (HER) performance. The DIW-printed Cu-Gr composite outperforms Cu-hBN and pristine Cu, achieving an overpotential of 129 mV at 20 mA cm^-2, a Tafel slope of 125 mV dec^-1, and excellent stability over 10 hours. Improved conductivity, charge transport, and active site exposure drive superior catalytic activity. Computational studies confirm that Gr (or h-BN) enhances the adsorption enthalpy, promoting catalytic interactions. This work highlights DIW-printed Cu-Gr composites as scalable, self-standing, and sustainable HER electrocatalysts.