Interfacial engineering of MXene/UiO-66 nanohybrids for efficient hydrogen evolution and urea oxidation

The steady exhaustion of fossil fuel reserves, coupled with the ever-growing global energy demand, has intensified environmental concerns and accelerated the search for alternative and sustainable approaches to energy production. This study developed a highly efficient MXene-based electrocatalyst by anchoring UiO-66 metal–organic framework (MOF) nanocrystals onto MXene sheets to form a robust MXene/UiO-66 hybrid composite for electrochemical hydrogen production. Microscopic characterization confirmed the successful integration of UiO-66 onto the MXene surface, showing well-distributed MOF nanocrystals closely wrapped around the indicating strong interfacial interactions. The tailored hybrid configuration promoted favorable reaction kinetics, allowing the system to achieve 100 mA cm⁻² with modest energy input, as reflected by overpotentials of 0.256 V for hydrogen evolution (HER) and 0.199 V for oxygen evolution (OER). The electrode showed a substantially enlarged electroactive surface area, with capacitance values of 29.8 and 36.4 mF cm⁻² respectively for HER and OER. Moreover, it delivered a steady electrochemical response during prolonged operation, sustaining a current density of 50 mA cm⁻² for 10 h without noticeable degradation. Additionally, the fabricated electrode showed competitive performance for the urea oxidation reaction (UOR), achieving a performance level on par with state-of-the-art Pt/C||RuO₂ catalysts. This enhanced catalytic response can be attributed to the synergetic interaction between the UiO-66 matrix and the MXene component. In this hybrid structure, the MXene facilitates efficient charge transfer, whereas the porous UiO-66 scaffold maintains structural stability by restraining MXene restacking and increasing the accessibility of catalytically active sites. Together, these features demonstrate the potential of MOF–MXene architectures as efficient and sustainable electrocatalysts for hydrogen production.