In-situ construction of three-dimensional ordered cobalt-nitrogen- carbon nanotubes integrated self-supporting electrode for efficiently electrocatalyzing oxygen reduction reaction

Abstract

Developing low-cost non-precious metal catalysts (NPMC) to replace Pt-based catalysts and rationally designing their integrated electrode to efficiently electrocatalyze oxygen reduction reaction (ORR) are greatly significant for facilitating the commercialization of fuel cells. Here, we report a novel self-supporting three-dimensional (3D) ordered integrated ORR electrode by a simple chemical vapor deposition (CVD) approach to in-situ grow Co,N co-doped carbon nanotubes (N-CNTs@Co) onto carbon paper modified by oxygen-containing functional groups (OCP). Benefiting from the moderate density of CNTs and abundant pyridinic N and graphitic N configurations as ORR active sites, the best-performing sample (N-CNTs-20@Co/OCP) exhibits outstanding ORR performance in both basic (0.1 mol L^–1 KOH) and acidic (0.1 mol L^–1 HClO₄) media, which is comparable to the one fabricated through the conventional method by spraying commercial Pt/C (20 wt%) onto OCP substrate (0.2 mg Pt cm^–2). This work can provide a feasible solution for the in-situ construction of efficient NPMC-based ORR integrated electrode.