Preparation of Au nanoparticles modified TiO_2 nanotube array sensor and its application as chemical oxygen demand sensor

摘要

Au nanoparticles(AuNPs) were electrodeposited at the highly ordered anatase TiO_2 nanotube array(TiO_2 NA) electrode under sonicating, and the AuNP-TiO_2 NA sensor was characterized by scanning electron microscope(SEM), X-ray photoelectron spectroscopy(XPS), X-ray diffraction(XRD). The photoelectrochemical experiments indicate the AuNP-TiO_2 NA sensor has lower photoelectro-resistance,higher photoelectrocatalytical activity and stability than that of pure TiO_2 NA sensor under the same conditions. The as-prepared sensor can be used for the determination of chemical oxygen demand(COD)in real samples, and the obtained results are comparable well with those of by standard K_2Cr_2O_7 method.The method proposed is simple, fast, cost effective, and environmentally friendly.