Virus-templated Pt–Ni(OH)2 nanonetworks for enhanced electrocatalytic reduction of water

Highlights: • Virus-templating enables the synthesis of high surface area nanostructured networks. • Pt–Ni(OH)₂ nanonetworks exhibit the highest HER mass activity to date in 1 M KOH. • Pt and Ni(OH)₂ exhibit cooperativity for enhanced mass activity. • Virus-templating enables higher mass activity through better Pt dispersion. -- Abstract: Clean hydrogen production via water electrolysis is incumbent upon the development of high-performing hydrogen evolution reaction electrocatalysts. Despite decades of commercial maturity, however, alkaline water electrolyzers continue to suffer from limitations in electrocatalytic activity and stability, even with noble metal catalysts. In recent years, combining platinum with oxophilic materials, such as metal hydroxides, has shown great promise for improving performance potentially by enabling stronger water dissociation at the surface of electrocatalysts. In this work, we leveraged the nanoscopic proportions and surface programmability of the filamentous M13 bacteriophage in the design, synthesis, and exceptional performance of 3D nanostructured biotemplated electrocatalysts for alkaline hydrogen evolution. We developed a facile synthesis method for phage-templated, Pt–Ni(OH)₂ nanonetworks, relying on scalable techniques like electroless deposition. After optimization of the platinum content, our materials display –4.9 A mg^–1_Pt at −70 mV versus the reversible hydrogen electrode, the highest reported mass activity in 1 M KOH to date, and undergo minimal changes in overpotential under galvanostatic operation at −10 mA cm^–2_geo. Looking forward, the performance of these catalysts suggests that biotemplating nanostructures with M13 bacteriophage offers an interesting new route for developing high-performing electrocatalysts.