A facile and high-yield approach to synthesize one-dimensional CeO2nanotubes with well-shaped hollow interior as a photocatalyst for degradation of toxic pollutants

Abstract

A facile, template-free and high-yield synthesis of single-crystalline cerium dioxide nanotubes (CeO₂-NT) has been reported via a “casually-modified” approach based on the hydrothermal treatment of Ce(OH)CO₃ precursors with alkali solution in an aqueous phase. This simple modification in synthesis procedures not only improves the yield of CeO₂-NT remarkably, but also gives rise to the formation of CeO₂-NT featuring excellent nanotubular open-ended structure with a well-shaped hollow interior. The collection techniques of BET, UV/visible diffuse reflectance spectra (DRS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analysis have been employed to characterize the morphology and optical properties of the as-prepared CeO₂-NT. Significantly, we demonstrate that CeO₂-NT exhibits a markedly enhanced photocatalytic activity and stability as compared with its counterpart of CeO₂ nanoparticles and commercial TiO₂ (P25) toward the degradation of aromatic benzene, a well-known toxic pollutant that commonly occurs in urban ambient air and is of significant concern regarding environmental health because of its toxic, mutagenic, or carcinogenic properties. This represents a first example to demonstrate the advantage of CeO₂ nanotubes as photocatalyst as compared to its counterpart of CeO₂ nanoparticles, clearly suggesting the morphology/shape-dependent photocatalytic behaviour of CeO₂ materials. Therefore, our current work not only offers a simple approach for fabrication of open-ended CeO₂-NT with well-shaped hollow interior, but also demonstrates the promising potential of the applications of CeO₂-NT, CeO₂-NT-based and other metal oxide nanotube-based materials in the area of photocatalysis, which will inevitably enrich the intriguing chemistry of morphology/shape-dependent heterogeneous photocatalysis and thermal catalysis.