Enhanced Photocatalytic Performances of CeO₂/TiO₂ Nanobelt Heterostructures

Abstract

CeO2 /TiO2 nanobelt heterostructures are synthesized via a cost-effective hydrothermal method. The as-prepared nanocomposites consist of CeO2 nanoparticles assembled on the rough surface of TiO2 nanobelts. In comparison with P25 TiO2 colloids, surface-coarsened TiO2 nanobelts, and CeO2 nanoparticles, the CeO2 /TiO2 nanobelt heterostructures exhibit a markedly enhanced photocatalytic activity in the degradation of organic pollutants such as methyl orange (MO) under either UV or visible light irradiation. The enhanced photocatalytic performance is attributed to a novel capture-photodegradation-release mechanism. During the photocatalytic process, MO molecules are captured by CeO2 nanoparticles, degraded by photogenerated free radicals, and then released to the solution. With its high degradation efficiency, broad active light wavelength, and good stability, the CeO2 /TiO2 nanobelt heterostructures represent a new effective photocatalyst that is low-cost, recyclable, and will have wide application in photodegradation of various organic pollutants. The new capture-photodegradation-release mechanism for improved photocatalysis properties is of importance in the rational design and synthesis of new photocatalysts.

Preparation of hollow core/shell CeO2@TiO2 with enhanced photocatalytic performance

“…Compared with TiO 2 and CeO 2 , the shape of HCSCTs is roughly similar with them. At the same time, a new broad band appeared at 550 cm -1 , suggesting that the rare earth element Ce exists in the product in the form of an oxide [24]. Figure 3 illustrates the TEM images of as-synthesized carbon spheres, C-Ce(OH) 3 composites and C-Ce(OH) 3 @ Ti(OH) 4 composites, respectively.…”

“…At the same time, the h ? in the VB of TiO 2 move to the VB of CeO 2 because the VB level of TiO 2 is higher than CeO 2 [24]. It produces plenty of powerful oxidant OH radicals by the reaction of H 2 O or OH -, which could rapidly attack pollutants and decompose the organic dye [20,24].…”

“…Compared with TiO 2 , we can clearly see the red shift and visible absorbance of HCSCTs. It may be that cerium oxide may absorb visible light, and UV light can be captured by the titanium dioxide [24]. The absorption edge of TiO 2 , CeO 2 nanoparticles, and HCSCTs is determined to be 393, 455, and 512 nm, respectively.…”

“…As a reactive rare earth oxides material, CeO 2 has many unique properties such as high capacity to store oxygen, unique UV absorbing ability, high thermal stability, and high electrical conductivity [20,21]. It has reported that coupling TiO 2 with CeO 2 not only enhances its structure properties but also improves the separation of electron-hole pairs and the photocatalytic activity [22][23][24].…”

Fabrication of inverse opal TiO2-supported Au@CdS core–shell nanoparticles for efficient photocatalytic CO2 conversion

“…[21][22][23][24][25] Among these tactics, constructing TiO 2 -based heterostructure has been demonstrated effective for improving photocatalytic efficiency through promoting the photogenerated charge separation, harvesting visible light and facilitating CO 2 activation. [26,27] Various types of second-component semiconductor of TiO 2 -based heterostructure have been reported, such as CdS, [28] CeO 2 [29] and ZrO 2 [30] and so on. On this basis, an electron transfer mediator (Pt, [31] Au, [32] and graphene oxide [33][34][35] ) embed in the heterostructure interface can strengthen the interface charge transfer and result in a vectorial electron transfer via a Z-scheme system, [36] which can efficiently improve photogenerated separation and photocatalytic activity.…”