The base vectors of the lattice are a ¯, b ¯, c ¯. The findings, controlling oxygen vacancy concentration to regulate the lattice parameters, could be a promising strategy for enhancing photoactivity oxidizing ability of photocatalysts. A lattice vector can be defined as V ¯ u a ¯ + v b ¯ + w c ¯ where u, v, w are integers describing the next lattice point out from the origin (at 0, 0, 0) with position u a, v b, w c and other lattice points are at n u a, n v b, n w c for integer n. Benefiting from the higher separation efficiency of photogenerated carriers and stronger oxidation capability, the BiPO 4 with the smallest lattice parameter exhibited reinforced photocatalytic removal efficiency of methylene blue, better repeatability and stability, which is 3.2 times as high as that of pristine BiPO 4. The photo-carriers separation efficiency and oxidizability are increased via controllable defect density to adjusting lattice parameters that can attract photogenerated electrons and lower valance band position, respectively. If one atom is at (0,0,0), then the closest atom is at (¼,¼,¼) times the lattice. We know that the closest 2 atoms are translated by ¼ of the lattice parameter. XPS, Raman, EPR, HRTEM, PL and UV–vis diffuse reflectance spectroscopy also identified that the types and concentrations of defect changed with various temperatures. Using the standard hard sphere model, nearest-neighboring atoms touch-that means they have a distance of, where is the radius of the atoms. The non-linear changes of lattice parameters calculated from XRD suggested that the lattice oxygen missed during thermal treatment. In this work, the photoactivity oxidation capability of bismuth phosphate were enhanced by the fine-tuning of lattice parameters with different oxygen defect concentrations. Oxide defect engineering exert huge impact on semiconductor photocatalysis, which not only can adjust the band-gap structure but also can act as electron trap for photoinduced carriers separation.
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