Enhanced photoelectrochemical and sensing performance of novel TiO2 arrays to H2O2 detection

Ag-decorated TiO2 nanowire arrays were facilely prepared by H2O2 corrosion of Ti and subsequent photodeposition of Ag. Array structures and photoelectric properties were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), UV–vis absorption spectroscopy and electrochemical methods. These results show that Ag quantum dots are evenly distributed on the surface of TiO2 nanowires. With an Ag content of 0.4 at%, the electrode's photocurrent density and photoconversion efficiency obtained optimum values of 0.29 mA/cm2 and 8.55%, respectively. The enhanced photoelectrochemical properties with Ag modification can be attributed to the extended visible light absorption range and improved separation of photo-generated carriers. Additionally, the modified nanowire arrays exhibited much stronger photoelectrocatalytic reduction activity toward hydrogen peroxide in comparison with pure TiO2 arrays or previously reported Ag electrodes.