Cobalt valence modulating in CoO incorporated carbon nanofiber for enhanced glucose electrooxidation

Abstract

Glucose fuel cells (GFCs) driven by abiotic catalysts are promising green power sources for portable or wearable devices. In this work, a CoO x incorporated carbon nanofiber (CoO x @CNF) catalyst with mixed valences cobalt oxides have been developed through partial oxidation of pyrolyzed electrospun Co 2+ /poly acrylonitrile fibers. The cobalt valence modulating could be achieved via regulating the incorporation ratio of cobalt acetate in precursors or the oxidation temperature of the pyrolyzed fibers. Electrocatalytic analyses show that the presence of CoO in CoO x @CNF will provide more active sites for glucose electrooxidation, and thus enhance the electrocatalytic performance significantly. As a result, the glucose fuel cell built with the CoO x @CNF anode containing both CoO and Co 3 O 4 delivered a maximum power density of 270 μW cm −2 , which is higher than that of other reported Co 3 O 4 based GFCs. This work provides a simple strategy to develop excellent transition metal catalysts for GFCs to expand their applications in portable and wearable energy devices. • CoO x incorporated carbon nanofibers were developed through partial oxidation of pyrolyzed electrospun Co 2+ /poly acrylonitrile fibers. • Cobalt valence modulating was achieved via regulating the oxidation temperature of the pyrolyzed fibers. • Presence of CoO increased the ratio of Co 2+ in CoO x @CNF that provide more active sites for glucose electrooxidation. • CoO x @CNF anode that containing both CoO and Co 3 O 4 delivers superior performance to other reported Co 3 O 4 based GFCs. • CoO x @CNF also achieves excellent performance in wearable patch type GFCs.