Facile Synthesis\nof Oxygen-Deficient CeVO<sub>4</sub>/Bi/Bi<sub>2</sub>MoO<sub>6</sub> Ternary Heterostructures with Bi-Mediated\nSwitching from Type‑I to Z‑Scheme Mechanism for O<sub>2</sub> and N<

The rapid assembly of ternary heterostructures with robust\nsolar\nlight absorption and high redox potential of photogenerated charged\nspecies is a pragmatic approach for achieving photocatalytic activation\nof tenacious atmospheric molecules. In the current study, a novel\nCeVO<sub>4</sub>/Bi/Bi<sub>2</sub>MoO<sub>6</sub> ternary heterostructure\nwas fabricated by in situ deposition of CeVO<sub>4</sub> over one-pot-synthesized\nBi/Bi<sub>2</sub>MoO<sub>6</sub> binary composite. The effect of the\nsalt precursor and reaction duration on the morphology and crystal\nstructure of Bi/Bi<sub>2</sub>MoO<sub>6</sub> was studied in detail.\nThe initial formation of Bi<sub>2</sub>MoO<sub>6</sub> nanoplates\nand their subsequent disintegration to nanorods upon prolonged reaction\ntime was observed due to concurrent leaching and reduction of Bi<sup>3+</sup> ions to plasmonic Bi<sup>0</sup> metal. The salt precursors\nalso crucially influenced the reaction kinetics for the formation\nof Bi/Bi<sub>2</sub>MoO<sub>6</sub> heterostructures. The CeVO<sub>4</sub>/Bi/Bi<sub>2</sub>MoO<sub>6</sub> ternary heterostructure\ndemonstrated a uniform deposition of CeVO<sub>4</sub> nanoparticles\n(10–20 nm) over Bi<sub>2</sub>MoO<sub>6</sub> nanorods that\nare embedded with ultrasmall Bi<sup>0</sup> nanodots (2–5 nm).\nThe ternary composites displayed improved surface area, porosity,\nsurface hydrophilic character, strong absorption in the entire UV–visible\nregion, and enhanced space charge separation property. The enhancement\nin optoelectronic feature is ascribed to the creation of surface oxygen\nvacancies and plasmonic nature of Bi nanodots. The optimized ternary\nphotocatalyst exhibited encouraging photocatalytic activity for H<sub>2</sub>O<sub>2</sub> generation (953 μM/g/h) and NH<sub>4</sub><sup>+</sup> production (131 μmol/g/h) with reaction kinetics\n7–20 and 4–5 times greater than those of pure semiconductors\nand CeVO<sub>4</sub>/Bi<sub>2</sub>MoO<sub>6</sub> binary heterostructure.\nThe apparent conversion efficiencies for O<sub>2</sub> and N<sub>2</sub> reduction were found to be 0.9% and 3.7%, respectively. Energy band\nstructure analysis and spectroscopic investigation of in situ generated\nradicals indicated a switching of charge migration route from Type-I\nin CeVO<sub>4</sub>/Bi<sub>2</sub>MoO<sub>6</sub> to Bi<sup>0</sup>-mediated all-solid-state Z-scheme for the CeVO<sub>4</sub>/Bi/Bi<sub>2</sub>MoO<sub>6</sub> composite, which accounted for its improved\nphotocatalytic activity.