Preparation of porous 3D Ce-doped ZnO microflowers with enhanced photocatalytic performance

Abstract

Porous 3D Ce-doped ZnO microflowers were prepared by hydrothermal method followed by low annealing process. The effects of Ce doping on the structural and photocatalytic properties of porous ZnO microflowers were investigated in detail. The samples were characterized by XRD, SEM, EDS, XPS, DRS, PL spectrum and BET surface area measurements. According to XRD analysis, both the crystalline structure of the synthesized pure ZnO and Ce-doped ZnO samples are hexagonal wurtzite. XPS results demonstrated that successfully synthesis of Ce 4+ doped ZnO. In addition, SEM morphologies showed the unique porous 3D flower-like structure of Ce-doped ZnO. Compared with the porous ZnO microflowers, the Ce-doped ZnO samples exhibit improved photocatalytic performance on decompose Rhodamine B (RhB). It is proposed that the special structural feature with a porous 3D structured and Ce modification lead to the rapid photocatalytic activity of the Ce-doped ZnO microflowers. Graphical AbstractPorous 3D Ce-doped ZnO microflowers were fabricated by using low temperature-hydrothermal method followed by a heat treatment process for the first time. Such the unique porous 3D structure of Ce-doped ZnO composites displays excellent photocatalytic activity on degradation of Rhodamine B. And the composite of Ce-doped ZnO is a promising candidate material for future treatment of contaminated water.

The Applications of Morphology Controlled ZnO in Catalysis

“…The high photocatalytic activity of Ni-doped ZnO hollow nanospheres was attributed to the high fraction of exposed polar facets, smaller particle size and larger surface area [232]. In addition, ZnO with different morphologies doped by rare-earth metals such as Ce and Eu were also explored [234,235]. The excellent photocatalytic activity for the degradation of RhB was attributed to crystallite size, narrowed band gap, and oxygen vacancies.…”

“…Main group metals, transition metals, and rare-earth metals are all reported in preparing doped ZnO [231][232][233][234][235][236]. Very recently, Li et al made Ga doped ZnO photonic crystals (GZO PCs) with various pore diameters and utilized them for RhB degradation [231].…”

“…In order to increase photocatalytic activities, many efforts have been made to prepare element doped ZnO [231][232][233][234][235][236]. Main group metals, transition metals, and rare-earth metals are all reported in preparing doped ZnO [231][232][233][234][235][236].…”

High performance Ce-doped ZnO nanorods for sunlight-driven photocatalysis

“…Due to the defects induced in the ZnO crystalline structure by Ce doping and the ability of this element to trap photogenerated charge carriers, Ce-doped ZnO (ZnO:Ce) particles have also gained high interest for photocatalysis. Recently, a few Ce 3+ - or Ce 4+ -doped ZnO photocatalyst containing large particles of spherical or needle morphology have been developed and their ability to degrade cyanide anions [28] or organic dyes [29–33] like methylene blue or methyl-orange has been demonstrated. The preparation of Ce–Cu, Ce–Pd or Ce–Ag co-doped photocatalysts to enhance the solar or the visible light catalytic response was also reported [34–36].…”

Enhanced photocatalytic activity of flowerlike CuO–ZnO nanocomposites synthesized by one-step hydrothermal method

“…It is worth noting that the UV emission intensity of all CuO-ZnO nanocomposites exhibits a distinct decrease compared to the pure ZnO. Since the UV emission mainly results from the recombination of photogenerated electrons and holes, a lower UV emission intensity indicates a lower recombination rate of photogenerated electron-hole pairs [26,27]. Therefore, a higher photocatalytic activity for CuO-ZnO nanocomposites would be expected.…”