Enhanced photoelectrochemical performance of mesoporous TiO2 photoanode prepared by multi-step evaporation-induced self-assembly method

Abstract

Mesoporous TiO2 films are promising in photocatalysis and photoelectrochemistry for energy and environment applications, because of its high specific surface area and regular mesopore structure. However, the performances of mesoporous TiO2 films are still limited by low catalyst loading due to the damage during the preparation process. In this study, a multi-step evaporation-induced self-assembly method is proposed to develop a mesoporous TiO2 photoanode with high catalyst loading. The prepared mesoporous TiO2 photoanodes possess not only high catalyst loading without damage but also large specific surface area, which provides more active sites. Moreover, regular mesopore structure is remained to benefit mass transport. Because of these merits, the mesoporous TiO2 photoanode prepared by the multi-step evaporation-induced self-assembly method exhibits superior performance than does conventional nanoparticles-packed TiO2 photoanode. The superiority of the mesoporous TiO2 photoanode prepared by this multi-step evaporation-induced self-assembly method is also demonstrated by incorporating it into a photocatalytic fuel cell. The short circuit current density and maximum power density increase by 90.9% and 25.0%, respectively. The present work provides a new way to prepare high-performance mesoporous TiO2 films for various photocatalytic and photoelectrochemical applications.