The findings reported here not only provide a green and rational design of high-performance photocatalysts but also show the applications ranged from catalysis to mitigation of polluted environment. The enhanced efficiency was further elucidated by theoretical investigations of density functional theory (DFT) calculations on the adsorption between tetracycline and CaCu 3Ti 4O 12. The detailed mechanism was proposed on the basis of crystal structure, unique morphology and spin trapping experiment, which reveals the roles of various active species for efficiency enhancement. The improved photoefficiency could be attributed to high abundant oxygen vacancies, surface properties, charge transfer and enhanced carrier separation due to the synergetic roles of active species, as is supported by active species trapping experiments and theoretical simulations. The degradation process follows a first-order kinetics, and excellent photooxidation performance was observed for octahedron and nanorod shaped CaCu 3Ti 4O 12 giving degradation rate constants of 1.14 × 10 −1 min −1 and 8.40 × 10 −2 min −1, respectively, much higher than those of polyhedron and cube shapes (their rate constants were 5.10 × 10 −2 min −1 and 2.80 × 10 −2 min −1, respectively). Purified polycrystalline powder samples of pentacene and quinacridone, respectively, were placed into 4 mm o.d. Cube, polyhedron, nanorod and octahedron shaped CaCu 3Ti 4O 12 morphologies were obtained by varying the salt composition during molten salt synthesis, and their visible-light photocatalytic capacities were tested for degrading an antibiotic, tetracycline. EPR Measurements: EPR spectra were recorded at room temperature on Bruker EMX X-band spectrometer (9.45 GHz) with a rectangular TE 102 cavity and Oxford EPR 910 continuous flow He cryostat operating between 4 and 300 K. Herein, we developed a strategy towards morphology tailoring in conjunction with oxygen vacancy in the structure of double perovskite CaCu 3Ti 4O 12.
Searching photocatalysts with sufficient utilization of sunlight and elucidating relevant reaction mechanism are still grand challenges in the field of semiconductor photocatalysis.
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