Cu and Al nanoparticles were prepared using a simple chemical etching method followed by a chemical reduction method. The synthesized metal nanoparticles were characterized by Fourier transform infrared (FTIR) spectroscopy, UV-visible spectroscopy, scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), high-resolution transmission electron microscopy (HRTEM), electron-dispersive (EDX) spectrum and water contact angle (WCA) measurements. The application of Cu and Al nanoparticles was tested towards the catalytic reduction of 4-nitrophenol (NiP), hexavalent chromium {Cr(VI)} and rhodamine 6G (R6G) dye in the presence sodiumborohydride (NaBH 4) as a reducing agent. From the UV-visible spectrum, the reduction rate constant (k app) and the induction time (T i) were determined and compared critically. The HRTEM analysis confirmed the nanosize of Cu and Al prepared by a simple chemical etching process followed by the chemical reduction method.