Facet-Dependent Photodegradation of Methylene Blue Using Pristine CeO Nanostructures.

This work comprises the shape- and facet-dependent catalytic efficacies of different morphologies of CeO, namely, hexagonal, rectangular, and square. The formation of different shapes of CeO is controlled using polyvinyl pyrrolidone as a surfactant. The surface reactivity of formation of differently exposed CeO facets is thoroughly investigated using UV-visible, photoluminescence, Raman, and X-ray photoelectron spectroscopies. A correlation between the growth of a surface-reactive facet and the corresponding oxygen vacancies is also established. Considering the tremendous contamination, caused by the textile effluents, the present study articulates the facet-dependent photocatalytic activities of pristine CeO for complete degradation of methylene blue within 175 min. The observed degradation time deploying pristine CeO as a catalyst is the shortest to be reported in the literature to our best knowledge.