Graphitic carbon nitride-carbon nanofiber as oxygen catalyst in anion-exchange membrane water electrolyzer and rechargeable metal–air cells

다국어 초록 (Multilingual Abstract)

<P><B>Abstract</B></P> <P>Graphitic carbon nitride-carbon nanofiber (g-CN-CNF) was synthesized as a bifunctional catalyst in an anion-exchange membrane water electrolyzer (AEMWE), and primary and rechargeable Zn–air cells. The g-CN-CNF catalyst shows high catalytic activity for oxygen reduction reaction and oxygen evolution reaction in half-cell, with low overpotentials and low Tafel slopes. The high activity is attributed to the synergistic effect of abundant active sites and the electrical conductivity following the pyrolysis of g-CN and CNF. As a result, AEMWE with the g-CN-CNF anode, the first application of a carbon-based catalyst, exhibits outstanding performance that is the highest record in the literature for AEMWE using a non-noble metal catalyst. In addition, the performance and durability of Zn-air cells with g-CN-CNF cathode outperform those fabricated with commercial platinum.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Graphitic carbon nitride/carbon nanofiber composite (g-CN-CNF) is proposed as bifunctional catalyst for both ORR and OER. </LI> <LI> g-CN-CNF catalysts exhibited high activity toward oxygen evolution and reduction reactions. </LI> <LI> Anion exchange membrane water electrolyzer with g-CN-CNF showed high performance despite the application of the carbonaceous material. </LI> <LI> Rechargeable Zn-air battery also exhibited the high performance and capacity retention. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>