Novel Tb2O3/Ag2Mo2O7 heterojunction photocatalyst for excellent photocatalytic activity: In-built Tb4+/Tb3+ redox center, proliferated hydroxyl radical yield and promoted charge carriers separation

The novel Tb2O3/Ag2Mo2O7 heterojunction photocatalyst was designed and synthesized successfully. X-ray diffraction and scanning electron microscope illustrated the crystalline phase and morphology of as-synthesized hybrid. X-ray photoelectron spectroscopy analysis displayed the element composite of Tb2O3/Ag2Mo2O7 photocatalyst and proved the existent of Tb4+/Tb3+ redox center in the heterojunction structure. Significantly, Tb2O3/Ag2Mo2O7 composite presented splendid photocatalytic performance under visible light irradiation, and the degradation rate of optimal Tb2O3/Ag2Mo2O7 composite is 3.2 times for methylene blue and 2.3 times for tetracycline compared to Ag2Mo2O7, respectively. Photoluminescence and photocurrent measurement results revealed that Tb2O3/Ag2Mo2O7 sample exhibited higher photoexited carries separation than Ag2Mo2O7. Moreover, the results of electron spin resonance test and capture experiment showed that the construction of Tb2O3/Ag2Mo2O7 heterojunction structure effectively boosted the production of powerful hydroxyl radials. The good stability and repeatability of Tb2O3/Ag2Mo2O7 heterojunction photocatalyst were illustrated by systematic experiments. This finding proposes an original strategy for modifying Ag2Mo2O7, and boosts the development of photocatalyst modification technology.