Controllable construction and efficient photocatalysis performance of Bi@Bi6O7FCl3 heterostructures exposed with the (012) plane bi-quantum-dots

It is imperative to find an environmentally friendly method to design photocatalysts for CO 2 reduction. In this work, ultrafine Bi 6 O 7 FCl 3 nanotubes were synthesized and used as a template to realize the reverse growth of Bi-quantum-dots at the interface of Bi@Bi 6 O 7 FCl 3 -X (X = 20/60/90) nanotube. The facile construction of the (012) plane on Bi quantum dots, with a diameter of approximately 2 nm, was achieved by electron beam irradiation. [Bi 6 O 7 ] 4+ cations and [Cl 4 ] 4− anions were first generated through the hydrothermal reaction, and the interaction between the anions and cations resulted in the [Bi 6 O 7 Cl 4 ] unit intermediate, in which the negatively charged [Cl 4 ] 4− separated the [Bi 6 O 7 ] 4+ layers from each other. In addition, F atoms, with a strong electronegativity, entered the [Cl 4 ] 4− layers, replacing a portion of the Cl atoms to form a new [FCl 3 ] 4− layer. The binding energy of Bi was reduced by 0.16 eV, as shown by the XPS results. The photocatalytic activity of Bi@Bi 6 O 7 FCl 3 -X (X = 20/60/90) was determined by the production of CO from CO 2 . After 4 h of monitoring, the CO production rate of Bi@Bi 6 O 7 FCl 3 –90 was 15.79 μmol·g −1 ·h −1 , which was 6.29 times that of Bi 6 O 7 FCl 3 . After 5 cycles, the CO production rate of Bi@Bi 6 O 7 FCl 3 -90 remained at approximately 61.07 μmol·g −1 .