Highly porous nanostructures: Rational fabrication and promising application in energy electrocatalysis

Porous nanostructures have been widely studied as electrocatalysts since they are structurally advantageous for enhancing the mass transport and providing accessible active sites in electrocatalytic reactions. Fabricating favorable porous nanostructures and understanding the structure–property relationship are important for the application of porous nanomaterials in energy electrocatalysis field. Considering this background, this review highlights the recent research on highly porous nanostructures, including the fabrication strategies and application in electrocatalysis. First, six basic synthesis methods for various porous electrocatalysts are introduced, i. e. templating method, using Kirkendall effect, by galvanic replacement reaction, through selective etching, from aerogel, and with reticular chemistry. Then, the application of porous nanomaterials in electrocatalysis is discussed from three aspects: activity, selectivity, and stability. Finally, the challenges and future research directions on porous electrocatalysts, including structure-controlled synthesis, potential applications and the related electrocatalytic mechanism investigation are put forward.