Efficient electrocatalysts derived from praseodymium-doped MOFs and MXene for oxygen reduction, hydrogen evolution, and oxygen evolution reactions

In response to the urgent need for high-performance non-precious metal electrocatalysts to address the energy crisis and reduce dependence on fossil fuels, we propose a novel approach to develop a highly selective and efficient electrocatalyst derived from metal-organic frameworks (MOFs). This electrocatalyst is designed for oxygen reduction reaction (ORR), hydrogen evolution reaction (HER), and oxygen evolution reaction (OER). The innovative synthesized catalyst combines the synergistic effects of cobalt (Co), MXene, and lanthanide praseodymium (Pr), which are synthesized via a simple co-precipitation method. Cobalt plays an important role in enhancing electron transfer kinetics, and the layered structure of MXene significantly increases the active surface area, and the lanthanide praseodymium enhances electrical conductivity and structural and chemical stability. All of these help the synthesized catalyst to have a low overvoltage, thereby facilitating ORR, HER, and OER processes. The interaction between these components enhances the catalytic performance and benefits from unique morphological features, abundant heterogeneous interfaces, and excellent structural stability. The synthesized electrocatalysts were characterized using various techniques including X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX), Fourier transform infrared spectroscopy (FTIR), and Brunauer-Emmet-Teller (BET) analysis, along with electrochemical evaluations such as cyclic voltammetry (CV), linear sweep voltammetry (LSV), chronoamperometry, and electrochemical impedance spectroscopy (EIS). Two separate samples of 10 %Pr-coreshell ZIF8@ZIF67/Mxene at 1:1 and 2:1 ratios showed exceptional electrocatalytic activity. For ORR, the samples showed impressive onset potentials of 0.904 V and 0.894 V (vs. RHE), while their HER onset potentials were recorded at -0.21 V and -0.20 V (vs. RHE). In terms of OER, the onset potentials were 1.62 V and 1.65 V, respectively. Notably, these materials showed outstanding stability and outperformed commercial Pt/C electrocatalysts, making them promising candidates for sustainable energy solutions.