Direct Electrodeposition of Electrically Conducting Ni3(HITP)2 MOF Nanostructures for Micro‐Supercapacitor Integration

Micro‐supercapacitors emerge as an important electrical energy storage technology expected to play a critical role in the large‐scale deployment of autonomous microdevices for health, sensing, monitoring, and other IoT applications. Electrochemical double‐layer capacitive storage requires a combination of high surface area and high electronic conductivity, with these being attained only in porous or nanostructured carbons, and recently found also in conducting metal–organic frameworks (MOFs). However, techniques for conformal deposition at micro‐ and nanoscale of these materials are complex, costly, and hard to upscale. Herein, the study reports direct, one step non‐sacrificial anodic electrochemical deposition of Ni3(2,3,6,7,10,11‐hexaiminotriphenylene)2 – Ni3(HITP)2, a porous and electrically conducting MOF. Employing this strategy enables the growth of Ni3(HITP)2 films on a variety of 2D substrates as well as on 3D nanostructured substrates to form Ni3(HITP)2 nanotubes and Pt@ Ni3(HITP)2 core–shell nanowires. Based on the optimal electrodeposition protocols, Ni3(HITP)2 films interdigitated micro‐supercapacitors are fabricated and tested as a proof of concept. Direct anodic and non‐sacrificial electrochemical deposition of an electrically conducting MOF Ni3HITP2, on a variety of metallic, semiconducting, and carbon substrates, with fine control over nanostructured architectures is reported. Ni3HITP2 MOF is integrated within micro‐supercapacitor interdigit device, using the method developed thereof, with enhanced capacitive storage and cycling stability.