Abstract
We report the optimization of both the support and the active phase of PdPt NPs supported on TiO2 nanowires to obtain highly active electro/photocatalysts for the oxygen reduction and water splitting reactions. This system displayed strong metal-support interactions, high concentration of oxygen vacancies, and PdPt NP were ∼2 nm in size. By optimizing the loading of PdPt, both the photo- and electrocatalytic activities were improved compared to commercial materials. Interestingly, a volcano plot was obtained from the activity and the PdPt composition, and the Pd0.22Pt0.78-TiO2/C sample afforded the optimal performance. For instance, the amount of hydrogen produced from water splitting was 11.6 mmol/gcatalyst. For the ORR, the activity was similar to a commercial Pt catalyst, but a lower Eonset (0.87 VRHE vs w 0.95 VRHE) was detected. The variations in the activities with the composition correlated well with the variations in the electronic effects and the concentration of oxygen vacancies.
