The novel 2-dimensional Bi2MoO6-Bi2O3-Ag3PO4 ternary photocatalyst with n-n-p heterojunction for enhanced degradation performance

The ternary Bi2MoO6-Bi2O3-Ag3PO4 photocatalysts were fabricated via hydrothermal and precipitation methods. Various characterizations proved that the Bi2O3 nanodots and spherical Ag3PO4 particles were embedded on Bi2MoO6 nanoflakes to form the ternary heterojunction. Compared to single Bi2O3, Bi2MoO6 and the binary Bi2MoO6-Bi2O3, the ternary composites at optimum Ag3PO4 content possess a significantly high visible-light degradation rate of tetracycline which is 3.2, 4.3 and 1.9 fold that of Bi2MoO6, Bi2O3 and Bi2MoO6-Bi2O3, respectively. The enhanced photocatalytic performance is attributed to the formation of ternary heterojunction that could greatly promote the transfer and separation of photo-generated carriers and extend the visible-light response range. The superoxide radical (·O2−) played a key role in the photocatalytic process and the photocatalytic mechanism of the ternary n-n-p heterojunctions were proposed. This work could offer a new insight in manufacturing ternary photocatalysts for the degradation of tetracycline under visible light irradiation.