A noble metal-free water oxidation electrocatalyst can be stable and obtained from earth-abundant materials, e.g., using copper-colloidal nanoparticles. The catalyst may contain nanobead and nanorod morphological features with narrow size distribution. The onset for oxygen evolution reaction can occur at a potential of 1.45 VRHE (η=220 mV). Such catalysts may be stable during long-term water electrolysis and/or exhibit a high electroactive area, e.g., with a Tafel slope of 52 mV/dec, TOF of 0.81 s−1, and/or mass activity of 87 mA/mg. The copper may also perform CO2 reduction at the cathode side. The Cu-based electrocatalytic system may provide a flexible catalyst for electrooxidation of water and for chemical energy conversion, without requiring Pt, Ir, or Ru.