Rational floor engineering of non-noble steel electrocatalysts supported on carbon supplies (steel@C) offers potential alternatives to realize sustainable vitality by electrocatalytic water splitting. Right here, the plastic wastes-based electrode supplies by mechanochemical synthesis and in situ pyrolysis doping afford low overpotentials (η₁₀=263 mV, Tafel slop =34 mV dec⁻¹), superior sturdiness, and operation simplification. The ball milling remedy promotes the stable dispersion of steel precursors in plastic, additional developing the core-shell construction with tunable thickness to control the exercise. The steel species was encapsulated by plastics-derived carbon shell and uniformly embedded within the extremely porous carbon help. By altering the steel precursor, different OER electrocatalysts based mostly on transition steel (Co, Ni, Mn and Fe) websites @C might speed up the oxygen evolution kinetics and the OER exercise pattern is Ni>Co≈Fe>Mn, superior to most carbon-based OER electrocatalysts and business IrO₂ to this point. The synergetic impact between the encapsulated steel and the high-curvature onion-like carbon shell play a elementary function within the superior OER catalytic efficiency. Moreover, this methodology presents an method for environment friendly utilization and upward recycling of plastics as high-value electrode supplies.