A mini-review on transition metals-based 1D nanotubular bifunctional electrocatalysts for overall water splitting

Research and development on bifunctional electrocatalysts for water electrolysis are essential in achieving cost reduction, simplifying electrolyzer design, and a sustainable hydrogen economy. One widely investigated approach to boosting electrocatalyst's efficiency is morphology control via one-dimensional nanostructures. Nanotubes are attractive among the different one-dimensional nanostructures due to their high surface-to-volume ratio, internal void space, low density, and fast charge/mass transport. This mini-review provides a concise account of transition metals-based nanotubular bifunctional electrocatalysts reported for overall water splitting. Nanotubes of precious and non-precious metals/alloys/compounds, their preparation methods, hydrogen and oxygen evolution reaction kinetics, overall water splitting performance, and mechanism of action are deliberated.