Supramolecular modulation of metalloporphyrinic porous aromatic frameworks using DWCNTs for enhanced hydrogen evolution activity

It is vitally imperative to concern the green and renewable energy on account of the increased global requirement for energy and the enhanced deterioration of the environment. Highly efficient electrocatalysts play crucial roles in renewable electrochemical energy storage and conversion systems. We demonstrate herein an effective strategy to induce cobalt-porphyrinic porous aromatic frameworks (CoCOP) onto double-walled carbon nanotubes (DWCNT) by supramolecular self-assembly and compare the electrocatalytic activity toward hydrogen evolution reaction (HER) performance of the resultant nanohybrids with different mass ratios. A HER activity trend of 1DWCNT-CoCOP > 2DWCNT-CoCOP > 0.5DWCNT-CoCOP > CoCOP > CoTPP is recorded, demonstrating the critical role of DWCNTs and charge transfer efficiency on the electrocatalysis . Remarkably, by tuning the mass ratios of DWCNTs to CoCOP, the derived 1DWCNT-CoCOP possesses the optimized HER activity with a low overpotential of 137 mV at 10 mA cm -2 , small Tafel slope (95 mV dec -1 ) and high Faraday efficiency (98%), superior to other control samples and a considerable number of electrocatalytic materials reported previously. The optimized HER activity for 1DWCNT-CoCOP can be attributed to several key factors, i.e. enhanced electronic conductivity , optimized active site exposure, enhanced reaction kinetics and improved wettability .