Egg Shell Mediated Ni5P4/Polypyrrole Electrocatalyst for Sustainable Water Splitting

A systematically crafted synthesis methodology of hydrothermal reaction followed by oxidative polymerization was implemented to fabricate nickel phosphide (Ni5P4) particles intricately deposited onto eggshell powder (ES). This process strived to prevent the agglomeration of Ni5P4 particles and was further reinforced with a polypyrrole (PPy) matrix, resulting in the formation of an integrated composite material known as Ni5P4@ES/PPy. The ES powder functions as a robust support system, facilitating the homogeneous growth of Ni5P4 particles; concurrently, the PPy matrix augments the stability and abundance of active sites within the electrocatalyst. This harmonious fusion of Ni5P4 particles with the ES and PPy matrix synergistically enhances the catalytic efficiency of the composite material, particularly in expediting the water-splitting process. The resultant Ni5P4@ES/PPy composite exhibits remarkable performance for both the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER) in a 1 M KOH solution. Furthermore, the as prepared catalyst delivers exceptional performance, promoting overall water splitting at a low cell voltage of 1.52 V to achieve a current density of 10 mA/cm2. This achievement outperforms the benchmark system Pt–C/NF∥RuO2/NF, which typically demand a higher voltage of 1.60 V. Additionally, the Ni5P4@ES/PPy composite demonstrates excellent durability for up to 40 h, further emphasizing its superior functionality and promising potential for practical applications in efficient water-splitting processes.