Synthesis of single-crystal-like nanoporous carbon membranes and their application in overall water splitting

Hong Wang,Mohamed Nejib Hedhili ,Chun Ma,Edy Abou-Hamad,Yu Han,Weili Yu,Shixiong Min,Zhixiong Liu,Haibo Zhu,Qiang Wang,Kuo‐Wei Huang ,Markus Antonietti,Yangyang Li,Jun Pan,Jiayin Yuan,Stuart Turner,Debao Li,Wei-Yi Zhang ,Lain‐Jong Li ,Tom Wu

doi:10.1038/ncomms13592

Abstract

Nanoporous graphitic carbon membranes with defined chemical composition and pore architecture are novel nanomaterials that are actively pursued. Compared with easy-to-make porous carbon powders that dominate the porous carbon research and applications in energy generation/conversion and environmental remediation, porous carbon membranes are synthetically more challenging though rather appealing from an application perspective due to their structural integrity, interconnectivity and purity. Here we report a simple bottom–up approach to fabricate large-size, freestanding and porous carbon membranes that feature an unusual single-crystal-like graphitic order and hierarchical pore architecture plus favourable nitrogen doping. When loaded with cobalt nanoparticles, such carbon membranes serve as high-performance carbon-based non-noble metal electrocatalyst for overall water splitting.

Highlights

Nanoporous graphitic carbon membranes with defined chemical composition and pore architecture are novel nanomaterials that are actively pursued
It is important to note that the preparation of gradient porous polymer membranes (GPPMs) is a mature and robust technique that can produce various pore profiles at desirable size scales
It was found that polymer precursors of moderate molecular weight (MW) and the cross-linking state of polyelectrolyte membranes are crucial to achieve morphology-maintaining carbonization

Summary

Introduction

Nanoporous graphitic carbon membranes with defined chemical composition and pore architecture are novel nanomaterials that are actively pursued. We report a simple bottom–up approach to fabricate large-size, freestanding and porous carbon membranes that feature an unusual single-crystal-like graphitic order and hierarchical pore architecture plus favourable nitrogen doping. For some carbon-based energy applications, such as electrodes in electrochemical energy conversion/storage, and nanoelectronic devices, precise control over the atomic order, local chemical composition, nanoscale morphology and complex pore architecture, as well as easy access to porous membranes of large size and large surface area, is highly relevant but cannot be fully met by the state-of-the-art synthetic protocols. We report a bottom–up approach for fabrication of hierarchically structured, nitrogen-doped, graphitic nanoporous carbon membranes (termed HNDCMs) via morphology retaining carbonization of a porous polymer membrane precursor. Pyrolysis enlarges the pore size in HNDCMs compared with that in GPPMs due to the considerable mass loss in the form of volatile species during carbonization (Supplementary Fig. 9)

Methods

Results

Conclusion