Bi ₂ O ₃ nanoparticles incorporated porous TiO ₂ films as an effective <i>p</i> ‐ <i>n</i> junction with enhanced photocatalytic activity

Abstract

Abstract Porous TiO 2 films decorated with Bi 2 O 3 nanoparticles are fabricated via alkali‐hydrothermal of titanium (Ti) plate by varying the reaction time. The amorphous TiO 2 is transformed into anatase after annealing the films at 500°C in air. The p ‐type Bi 2 O 3 nanoparticles are successfully assembled on the surface of porous n ‐type TiO 2 films through the ultrasonic‐assisted successive ionic layer adsorption and reaction (SILAR) technique to form Bi 2 O 3 /TiO 2 nanostructure by the two cycles. The obtained Bi 2 O 3 /TiO 2 films are consisted of a well‐ordered and uniform porous structure with an average pore diameter of about 100‐200 nm containing homogeneously dispersed Bi 2 O 3 nanoparticles of ~5 nm diameter. Moreover, the resultant composites present excellent photocatalytic performance toward methyl blue (MB) degradation under UV and visible light irradiation, which could be mainly ascribed to the enhanced light adsorption capacity of unique composite structure and the formation of p ‐ n heterojunctions in the porous Bi 2 O 3 /TiO 2 films. This research is helpful to design and construct the highly efficient heterogeneous semiconductor photocatalysts.