Photocatalytic H2 generation using dewetted Pt-decorated TiO2 nanotubes - Optimized dewetting and oxide crystallization by a multiple annealing process

摘要

In the present work we use TiO2 nanotube arrays, carrying a Pt coating thatis optimally dewetted, as a photocatalyst to generate H2. In order to achieve amaximum H2-generation efficiency, on the one hand an ideal thermal dewetting ofthe Pt layer into nanoparticles is needed that requires an oxygen free heattreatment, and on the other hand an optimal crystallization of the TiO2nanotubes into anatase with reduced defect density is achieved only byannealing in O2 containing environment. To overcome this issue, we combineadequate reducing and oxidizing conditions in a multiple annealing treatment,and obtain Pt-decorated anatase TiO2 nanotubes showing significantly enhancedphotocatalytic H2 generation ability.