Helical 3D-printed metal electrodes as custom-shaped 3D platform for electrochemical devices

3D-printing represents an emerging technology that can revolutionize the way object and functional devices are fabricated. Here the use of metal 3D printing is demonstrated to fabricate bespoke electrochemical stainless steel electrodes that can be used as platform for different electrochemical applications ranging from electrochemical capacitors, oxygen evolution catalyst, and pH sensor by means of an effective and controlled deposition of IrO₂ films. The electrodes have been characterized by scanning electrode microscopy and energy dispersive X-ray spectroscopy before the electrochemical testing. Excellent pseudocapacitive as well as catalytic properties have been achieved with these 3D printed steel-IrO₂ electrodes in alkaline solutions. These electrodes also demonstrate Nernstian behavior as pH sensor. This work represents a breakthrough in on-site prototyping and fabrication of highly tailored electrochemical devices with complex 3D shapes which facilitate specific functions and properties. On-site design and fabrication of metal electrodes for different electrochemical applications is possible, thanks to metal 3D printing. Helical-shaped steel electrodes - fabricated through a selective laser melting technology - are electrochemically modified with IrO₂ films and used as capacitors, pH sensors, and catalysts for oxygen evolution reaction, demonstrating excellent performance.