Abstract
Pb(2) Ti(2) O(5.4) F(1.2) modified with various metal cocatalysts was studied as a photocatalyst for visible-light H(2) evolution. Although unmodified Pb(2) Ti(2) O(5.4) F(1.2) showed negligible activity, modification of its surface with Rh led to the best observed promotional effect among the Pb(2) Ti(2) O(5.4) F(1.2) samples modified with a single metal cocatalyst. The H(2) evolution activity was further enhanced by coloading with Pd; the Rh-Pd/Pb(2) Ti(2) O(5.4) F(1.2) photocatalyst showed 3.2 times greater activity than the previously reported Pt/Pb(2) Ti(2) O(5.4) F(1.2) . X-ray absorption fine-structure spectroscopy, photoelectrochemical, and transient absorption spectroscopy measurements indicated that the coloaded Rh and Pd species, which were partially alloyed on the Pb(2) Ti(2) O(5.4) F(1.2) surface, improved the electron-capturing ability, thereby explaining the high activity of the coloaded Rh-Pd/Pb(2) Ti(2) O(5.4) F(1.2) catalyst toward H(2) evolution.