Efficient Doping Induced by Charge Transfer at the Hetero-Interface to Enhance Photocatalytic Performance

The construction of heterojunction photocatalysts is an effective method to improve photocatalytic efficiency since the potential gradient and built-in electron field established at the junction could enhance the efficiency of charge separation and interfacial charge transfer. Nevertheless, heterojunction photocatalysts with strong built-in electron fields remain difficult to build since the two adjacent constitutes must be satisfied with an appropriate band alignment, redox potential, and carrier concentration gradient. Here, an efficient charge transfer-induced doping strategy is proposed to enhance the heterojunction built-in electron field for stable and efficient photocatalytic performance. Carrier transfer tests show that the rectification ratio of the n-TiO2–X/n-BiOI heterojunction is significantly enhanced after being coated with graphene oxide (GO). Consequently, both the hydrogen production and photodegradation performance of the GO composite heterojunction are considerably enhanced compared with pure TiO2–X, BiOI, and n-TiO2–X/n-BiOI. This work provides a facile method to prepare heterojunction photocatalysts with a high catalytic activity.