Enhanced electrocatalytic performance of 2D Ni-MOF for ethanol oxidation reaction by loading carbon dots

Due to the scarcity of precious metals, it is urgently desired to develop novel non-precious metal catalysts for ethanol oxidation reactions (EOR) to improve the property of direct ethanol fuel cells (DEFCs), but it is still a huge challenge. Currently, nickel-based catalysts are known as one of the candidates to replace precious metal catalysts. Among them, nickel-based metal-organic frameworks (MOFs) have been treated as a new platform towards the development of electrocatalysts. Herein, a 2D Ni-MOF 1 was solvothermally synthesised, and combines with carbon dots (CDs) for enhancing the conductivity of MOF 1 to prepare finally MOF1[email protected] composites. The current density (j) of the optimal MOF1[email protected] toward EOR is 119 ​mA ​cm−2, which exceed those of the EOR catalysts previously reported. Meanwhile, the optimal MOF1[email protected] has low Tafel slope (93.9 ​mV dec−1) and high exchange j value (2.06 ​× ​10−5 ​A ​cm−2). The excellent performance of MOF1[email protected] is mainly ascribed to accelerating EtOH adsorption on the surface of the catalyst and charge transfer after the introduction of CDs. After 10000 ​s durability test, the retention rate of the j value of MOF1[email protected] is 90% of that (118 ​mA ​cm−2) of the original one, which indicates that MOF1[email protected] catalyst has good stability. So MOF1[email protected] is expected to be used as a cost-effective EOR electrocatalyst due to its simple preparation method, excellent activity and stability.