In-situ construction of core–shell structured TiB2-TiO2@g-C3N4 for efficient photocatalytic degradation

Abstract

g-C3N4 based heterojunction photocatalysts attract much attention as degradation materials for organic pollutants due to their wide light absorption range and rich photoinduced carriers. Strategies to effectively improve photoelectron separation and transmission have become a research hotspot. Herein, a novel heterojunction TiB2-TiO2@g-C3N4 photocatalyst with core–shell structure was constructed by in-situ growth of g-C3N4 on the TiB2-TiO2 cores using one-step calcination method. The composite processes a higher photodegradation performance of Rhodamine B (RhB) and 4-Chlorophenol (4-CP) compared to the pure g-C3N4. The results show that the surface of TiB2-TiO2 cores contains numerous ‘TiB2 bridges’, as photoinduced carriers transport channels, which effectively accelerate photoinduced e- and h+ migration. In addition, the g-C3N4 coated on TiB2-TiO2 cores forms a Z-scheme heterojunction, which hinders the recombination of photogenerated charges resulting in a longer electron lifetime. Furthermore, the TiB2 also could act as acceptors of electrons for the formation of •O2–. The main active substances for degradation of RhB are •OH, •O2– and h+. This strategy is applicable to design highly capable heterojunction photocatalysts by constructing fast electronic transmission channels.