Boosting oxygen evolution reaction at hydrothermally synthesized V-MXene interface with Iron Pthalocynaine

Abstract

Oxygen evolution reaction (OER) is a pivotal electrochemical reaction process for many renewable energy technologies. Due to the sluggish OER kinetics, designing and fabricating efficient low-cost non-precious metal catalysts is one of the crucial but very challenging steps to develop electrochemically active and stable OER electrocatalyst. Conventionally, MXenes are prepared from hydrofluoric (HF) acid but the acute toxicity of HF acid impedes the wide utilization in energy related applications. Herein, V₂C MXene is prepared through hydrothermal low level of danger HF free synthetic approach and synergistically coupled with Iron Phthalocyanine electrocatalyst. Moreover, the better OER efficiency of HF free hydrothermally synthesized MXene (with an overpotential of 373 mV) is described as compared to HF based MXene of OER overpotential of 384 mV at the current density of 10 mA/cm². The inserted HT MX sheets within the matrix of FePc rods exhibited the desired crystallinity of hybrid. The XPS results suggest a synergistic chemical interaction between MX sheets and FePc molecules that modifies the electronic structure of the composite ensuring reduced charge transfer resistance. Consequently, the FePc:HT MX has shown appreciable OER electrocatalytic activity with an overpotential of 366 mV at a current density of 50 mA cm⁻², Tafel slope of 5.36 mV dec⁻¹ in 1 M KOH. Besides, the significant interaction between metallic centers and MXene support prevent detachment or agglomeration of active centers providing maximum interaction with the electrolytic ions, quick ionic OH⁻ transportation, speedy and stable electron transfer thus ensure the long-term stability of composite during 50 h continuous operation of OER. In essence, this study features a facile approach for the hydrothermally synthesized MX sheets-based composites as advanced electrocatalysts for renewable energy applications.