Coupled spinel manganese-cobalt oxide and MXene electrocatalysts towards efficient hydrogen evolution reaction

Although nanostructured spinel oxides have been considered as potential electrode materials for the hydrogen evolution reaction (HER), their catalytic properties still need to be substantially improved to meet the requirements of practical use. In this work, we present the rational design and controllable synthesis of nanosized spinel manganese-cobalt oxide strongly coupled with ultrathin Ti3C2Tx MXene nanosheets (MnCo2O4/Ti3C2Tx) through a facile and cost-effective strategy. The effective combination of spinel MnCo2O4 with Ti3C2Tx nanosheets generates a number of attractive structural features with strong synergistic effects, such as highly accessible surface areas, intimate 0D/2D interfacial connection, full exposure of abundant active sites, optimized electronic structure, and excellent electron conductivity, all of which are very desirable for the HER process. Consequently, the resulting MnCo2O4/Ti3C2Tx electrocatalyst possesses an unusual HER ability with a low onset potential of only 51 mV, a small Tafel slope of 79 mV dec- 1 and exceptional long-term stability, markedly outperforming the bare MnCo2O4 and Ti3C2Tx electrocatalysts.

Automated summary

This work presents the rational design and controllable synthesis of nanosized spinel manganese-cobalt oxide strongly coupled with ultrathin Ti3C2Tx MXene nanosheets (MnCo2O4/Ti3C2Tx). The resulting electrocatalyst exhibits highly accessible surface areas, abundant active sites, optimized electronic structure, and excellent electron conductivity, which leads to an exceptional hydrogen evolution reaction (HER) ability.