Efficient removal of phenol pollutants with CuO nanorods and nanoparticles as a reusable heterogeneous catalysts

Cupric oxide (CuO) nanorods and nanoparticles were successfully fabricated by hydrothermal route and characterized as a catalyst. Instruments such as XRD, FT-IR, SEM, TEM, HR-TEM, EDS, and the N₂ adsorption–desorption isotherm were used to characterize products. The possible crystal growth mechanism of rod structure was suggested by altering hydrogen peroxide concentration, time and temperature. Emerson’s method and the chemical oxygen demand (COD) test evaluated the catalytic degradation of phenol solution over as-prepared materials in an O₂ air bubbling system. The reaction is first-order and is respected due to the reaction being raining with excess oxygen. The impact of pH, catalyst loading and mechanism of catalytic reaction were estimated. An over 98% phenol removal was achieved by CuO nanorods within 50 min, and the experimental values were well-matched with the linear fit model (R² = 0.998), and the rate constant was found to be 6.89 × 10^–2 min⁻¹. The reaction goes through an initial period of adsorption and then moves to a higher activity and is more stable. Therefore, the as-prepared CuO nanorods can be employed as a potential catalyst substance for the degradation of phenol in the wastewater due to the exterior morphology, surface area, pore size, and miller-index of the crystals.