Recent innovations of silk-derived electrocatalysts for hydrogen evolution reaction, oxygen evolution reaction and oxygen reduction reaction

Numerous researches have proved that heteroatom-doping, especially N-doping, is able to enhance the electrocatalytic performance for carbon materials toward water electrolysis and oxygen reduction reaction. Hence, the production of N-doped carbon materials from cheap and earth-abundant precursor resources such as biomass materials has great potential in the application of these fields. Among various biomass precursors, silk, a N-rich protein, is an ideal candidate for the synthesis of N-doped carbon. Meanwhile, without addition of chemical N-rich precursors during preparation, N-doped carbon derived from silk is clean and easy to synthesize but possesses superb performance. Silk derived catalysts can exhibit overpotential of 61 mV @ 10 mA/cm(2) (49 mV @ 10 mA/cm(2) of commercial 20%Pt/C for comparison) and Tafel slope of 89 mV/dec towards hydrogen evolution reaction. To date, great progress has been made in the application of silk-derived catalysts to electrocatalysts, but there exists few summary work. Herein, we summarized recent progress on silk-derived electrocatalysts, focusing on their preparation process and their application on water electrolysis and oxygen reduction reactions. This review provides consolidated accounts of silk-derived catalysts and highlights ideas of their preparation and their performance. (c) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.