Strongly coupled cobalt-molybdenum-boron nanoparticles anchored on graphene oxide as highly efficient electrocatalyst for oxygen evolution reaction

Graphene oxide (GO) exhibits unique layered structures and excellent electrical conductivity, and the multiple surface termination groups are favorable for hosting impressive performance for electrochemical reactions. Therefore, a two-dimensional layered GO-based catalyst may become a novel high-efficiency electrocatalyst to replace traditional noble metal electrocatalysts. Herein, Co-Mo-B/GO (CMBG) nanocomposites are successfully prepared by electroless deposition for the oxygen evolution reaction (OER). GO constructs multi-layer three-dimensional structure with large surface area, which helps to increase electron transfer and mass transfer within the materials. Due to the introduction of Mo, the aggregation of nanoparticles on GO is reduced, and also the synergistic effect among Co, Mo, and B improves the electrocatalytic performance of as-prepared materials. Moreover, electrochemical tests reveal that the CMBG electrocatalyst can reduce the charge transfer resistance toward the OER and increase electrochemical active sites, leading to enhancing the OER performance. When the molar ratio of Mo/(Co + Mo) is 3:100, overpotential of CMBG is only 270 mV at 10 mA cm-2. In addition, CMBG shows long-term electrocatalytic stability even after 24-h test. This work provides a feasible way for the preparation of ternary boride electrocatalyst for OER.