Direct Z-scheme heterojunction rutile-TiO2/g-C3N4 catalyst constructed by solid grinding method for photocatalysis degradation

Abstract

Schematic illustration of RhB photocatalytic reaction mechanism over the rutile-TiO 2 /g-C 3 N 4 photocatalyst. • The rutile-TiO 2 /g-C 3 N 4 photocatalyst is constructed by a simple solid grinding method. • The optimized rutile-TiO 2 /g-C 3 N 4 photocatalyst has more excellent photocatalytic performance than the pure rutile-TiO 2 and g-C 3 N 4 . • The direct Z-scheme heterojunction mechanism is proposed over the rutile-TiO 2 /g-C 3 N 4 photocatalyst. Constructing a direct Z-scheme heterojunction is an effective method to improve the catalytic performance of photocatalyst. Here, the direct Z-scheme heterojunction rutile-TiO 2 /g-C 3 N 4 photocatalyst was constructed by a simple solid grinding method. This method can not only avoid the weak activity of rutile-TiO 2 in high synthesized temperature condition, but also precisely control the amount of g-C 3 N 4 . The evaluation of photodegradation reaction suggests that the rutile-TiO 2 /g-C 3 N 4 photocatalyst exhibits higher photodegradation efficiency than the pure rutile-TiO 2 and the pure g-C 3 N 4 under simulated sunlight irradiation, and the optimal photocatalytic performance is achieved when the mass ratio of rutile-TiO 2 to g-C 3 N 4 is 2:5. The experimental results prove that a direct Z-scheme heterojunction is formed over the rutile-TiO 2 /g-C 3 N 4 photocatalyst, which promotes the effective electron-hole separation and the higher redox potential over the rutile-TiO 2 /g-C 3 N 4 photocatalyst. This work provides an attractive strategy to construct the direct Z-scheme photocatalyst consisted of rutile-TiO 2 and g-C 3 N 4 .