Alkaline hydrogen production promoted by small-molecule modification on flowerlike Co2(OH)2CO3

Developing a low-cost and high-efficiency nonprecious metal-based catalyst for hydrogen evolution reaction (HER) is of great significance for the utilization of hydrogen energy. In this work, we report a molecular-modification strategy to fabricate a self-supported hydrogen evolution electrode, specially by grafting the macrocyclic molecules (HHTP = 2,3,6,7,10,11-hexahydroxytriphenylene) on the surface of a cobaltous dihydroxycarbonate (COC) seed layer. The HHTP-COC electrode is endowed with a rod-like structure, which provides favorable access for charge transportation and mass exchange. The macrocyclic molecule structure in HHTP can be grafted on COC and improve the electrical conductivity, while the interaction between HHTP and COC induces the rearrangement of charge configuration on the surface. Due to the combination effects of several aspects, the HHTP-COC electrode achieves astonishing HER activity, with a low overpotential of 61.0 mV (η10, at the current density of 10 mA cm−2) and excellent stability in alkaline condition. This kind of interface engineering based on the organic molecules can be applied to the design and manufacture of electrocatalysts in the field of energy conversion and storage.