Fig. 8From: Noble metal-free two dimensional carbon-based electrocatalysts for water splittinga Schematic of the synthetic route of Ni–N–S doped porous carbon. b SEM. c TEM image. d HRTEM and inset of C is the SAED pattern. e Representation of structural model of Ni–N–S doped porous carbon. f, g Electrochemical performances of Ni–N–S doped porous carbon with other control samples. a–g Reproduced with permission from Ref. [116]. Copyright 2019, Nature Publishing GroupBack to article page