Superhydrophilic Phytic Acid‐doped Conductive Hydrogels as Metal‐free and Binder‐free Electrocatalysts for Efficient Water Oxidation

Recently, metal‐free heteroatoms doped‐carbon nanomaterials have emerged as promising electrocatalysts for oxygen evolution reaction (OER), but the synthesis of them suffers from tedious process involving energy‐wasting calcination. The molecular electrocatalysts offer attractive substitutes for OER; especially, natural organic molecules, i.e. phytic acid (PA), have advantages of easy production, low‐cost and environment‐friendly. Here, we selected PA as platform molecules to investigate the activity of carbons on organic molecules by means of DFT calculations and experiments. The results indicated that the positively charged carbons on PA were very active for OER. And then, the PA molecules were fixed into a porous and conductive hydrogel with a superhydrophilic surface, which was directly exploited as a metal‐free electrocatalyst for OER, revealing a small overpotential of 340 mV at 10 mA cm‐2, a Tafel slope of 54.9 mV dec‐1, and outstanding stability of 20 h, outperforming most metal‐free electrocatalysts. Besides the active sites on PA, the high OER activity was also related to the porous and conductive networks on the hydrogel, which allowed fast charge and mass transport during OER. Therefore, this work provided a metal‐free organic molecule‐based electrocatalyst to replace carbon nanomaterials for efficient OER.

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