부산대학교 도서관

To alleviate the sluggish oxygen evolution reaction (OER) kinetics, it's urgent to develop electrocatalysts with high activity and low cost. In this work, Fe doped metal organic frameworks (Ni)/carbon black composites were synthesized via a facile hydrothermal method. Benefiting from the direct use of metal organic frameworks (MOFs) for OER, numerous and highly dispersed active sites are exposed to the electrolyte and reactants. By regulating Ni/Fe ratios, a high electrochemical active surface area (ECSA) and high relative surface content of active Ni3+ species are obtained, which mainly contribute to the high OER activity. Besides, the introduced carbon black (CB) was found to enhance the charge-transfer efficiency of the electrocatalysts, which is also favorable for OER. The optimal Ni9Fe1-BDC-0.15CB electrocatalyst shows excellent OER activity with the low overpotential of ~290 mV at 10 mA cm−2 and the Tafel slope of ~76.1 mV dec−1, which is comparable to RuO 2 and other MOFs-based OER electrocatalysts reported in recent years. Image 1 • Bimetal NiFe MOFs/CB composite was directly used as OER electrocatalyst. • NiFe-BDC-CB shows a structure of nanosheets decorated with CB nanospheres. • A moderate Ni/Fe ratio can improve relative contents of Ni3+ active sites for OER. • NiFe-BDC-CB shows high OER electrocatalytic activity and durability. [ABSTRACT FROM AUTHOR]