Influence of controlled Pd nanoparticles decorated TiO2 nanowire arrays for efficient photoelectrochemical water splitting

Abstract

This work depicts the synthesis of controllable Pd nanoparticles decorated TiO2 nanowire arrays by electrospray technique. By varying the substrate temperature and volume of precursor solution, Pd/TiO2 hybrid structure with different sizes and deposition yield was precisely controlled. The highest photocurrent density of the Pd/TiO2 photoanode was 1.4 mA cm−2 at 1.23 V vs. RHE, which was approximately 5 times higher than the pristine TiO2. The onset potential with a significant cathodic shift of 80 mV compared to the pristine TiO2 was also observed. To the best of our knowledge, the obtained photocurrent showed the optimal photocurrent density and high stability compared with previous reports. It is also found that the photoelectrochemical performance is closely related to the size and deposition quantity of Pd nanoparticles. According to the results, the enhanced PEC performance can be attributed to the Schottky junction, charge transfer and the enhancement about the separation efficiency of the photogenerated electrons and holes betweenTiO2 and Pd NPs. This result demonstrated that this method may design a new and green strategy for synthesizing the well-defined morphologies, compositions, and sizes of the hybrid nanomaterial for photocatalytic hydrogen generation, photocatalytic CO2 reduction and photosynthesis of organic molecules.