Carbon quantum dots decorated Ba0.5Sr0.5Co0.8Fe0.2O3-δ perovskite nanofibers for boosting oxygen evolution reaction

Perovskites are emerging as a new research frontier for oxygen evolution reaction (OER), however, their activity and durability are still far from desirable. Herein, we highlight a facile approach to boosting the perovskite electrocatalysis for OER by the coupling of carbon quantum dots (CQDs). The as-prepared CQDs decorated Ba0.5Sr0.5Co0.8Fe0.2O3-delta-perovskite nanofibers (CQDs@BSCF-NFs) catalyst achieves a low overpotential of 0.35 V at 10 mA cm(-2), favorably outperforming the individual BSCF-NFs and the commercial IrO2. The CQDs@BSCF-NFs catalyst demonstrates an outstanding current density of 140.8 mA cm(-2) at a potential of 1.65 V vs. RHE, which is (similar to)5 and 19 times higher than that of BSCF-NFs and IrO2. This significantly enhanced activity is attributed to the enlarged specific surface area, the increased surface oxygen vacancies as well as the synergy between CQDs and BSCF. Moreover, the CQDs@BSCF-NFs catalyst also exhibits a high electrocatalytic stability for 10 h operation.