Factors affecting photocatalytic performance through the evolution of the properties due to the phase transition from $ NaBiO_{3} $·$ 2H_{2} $O to $ BiO_{2−x} $

Abstract The phase transition process of a photocatalytic system from $ NaBiO_{3} $·$ 2H_{2} $O to $ BiO_{2−x} $ has been investigated to understand the important factors that affect photocatalytic performance in a composite system. It is found that a proper amount of $ BiO_{2−x} $ on the surface of...
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Abstract The phase transition process of a photocatalytic system from $ NaBiO_{3} $·$ 2H_{2} $O to $ BiO_{2−x} $ has been investigated to understand the important factors that affect photocatalytic performance in a composite system. It is found that a proper amount of $ BiO_{2−x} $ on the surface of $ NaBiO_{3} $·$ 2H_{2} $O could effectively suppress the electron/hole recombination and increase the exposed reactive sites for photocatalytic reaction. A fully covered $ BiO_{2−x} $ on $ NaBiO_{3} $·$ 2H_{2} $O results in a dramatical decrease of photocatalytic degradation of dye. An over long hydrothermal process can result in $ BiO_{2−x} $ with reduced oxygen vacancies, which degrades the photocatalytic activity. Furthermore, the photocatalytic reduction ability of $ CO_{2} $ conversion has been investigated, indicating that the surface activity to different reactants also directly affects the catalytic performance. The investigation of the gradient phase transition process presents a clear guidance to construct a desired photocatalytic system, in addition to selecting gradient materials with suitable bandgap structure and a morphology with different fraction and distribution of each component. The defect evolution of each component during construction of a composite is also an important factor that should be optimized and considered in making a composite to achieve high photocatalytic efficiency. Ausführliche Beschreibung