Synthesis of ZnO Nanoparticles Doped with Cobalt Using Bimetallic ZIFs as Sacrificial Agents

Abstract

<jats:p>We report here a simple two-stage synthesis of zinc–cobalt oxide nanoparticles. We used Zn/Co-zeolite imidazolate framework (ZIF)-8 materials as precursors for annealing and optional impregnation with a silicon source for the formation of a protective layer on the surface of oxide nanoparticles. Using bimetallic ZIFs allowed us to trace the phase transition of the obtained oxide nanoparticles from wurtzite ZnO to spinel Co3O4 structures. Using (X-ray diffraction) XRD and (X-ray Absorption Near Edge Structure) XANES techniques, we confirmed the incorporation of cobalt ions into the ZnO structure up to 5 mol.% of Co. Simple annealing of Zn/Co-ZIF-8 materials in the air led to the formation of oxide nanoparticles of about 20–30 nm, while additional treatment of ZIFs with silicon source resulted in nanoparticles of about 5–10 nm covered with protective silica layer. We revealed the incorporation of oxygen vacancies in the obtained ZnO nanoparticles using FTIR analysis. All obtained samples were comprehensively characterized, including analysis with a synchrotron radiation source.</jats:p>

Tri-metallic ZIF mediated synthesis of defect rich N-doped Co3O4/ZnO/NiO S-scheme heterostructure for detection and photocatalytic degradation of persistent organic pollutants

“…The bands at around 550 cm −1 and 430 cm −1 corresponded to Zn–O stretching vibration modes. 26 Meanwhile, the bands at around 666 cm −1 and 550–590 cm −1 could be attributed to the stretching vibration of Co 2+ in tetrahedral coordination and Co 3+ in octahedral environment, respectively. Hence, FT-IR studies clearly indicate the successful formation of all the synthesized materials.…”

Special Issue “Wet Chemical Synthesis of Functional Nanomaterials”

“…The synthesis of nanomaterials with novel or improved properties is the basis of advancement in technological applications. In this view, Soldatov and coworkers presented the synthesis of zinc–cobalt mixed oxide nanoparticles using ZIF-8 (zeolitic imidazolate frameworks) metal organic frameworks (MOFs) as sacrificial agents [ 3 ]. The authors observed doping of cobalt into zinc oxide, as well as the formation of spinel Co 3 O 4 depending on composition, and they also discovered that the addition of a silicon source could provide a protective SiO 2 layer on the surface of the nanoparticles.…”

“…This Special Issue aimed to provide a forum to present some of the latest results in the area of synthesis, characterization and application of functional nanomaterials which are synthesized using wet chemical methods. With five articles and one review covering polymer oxide composites for magnetic applications [1], TiO 2 /Au nanostructured films for hydrogen sensors [2], mixed oxide nanoparticles derived from sacrificial metal organic frameworks [3], highly doped metal oxide colloidal nanocrystals for plasmonics [4], sol-gel derived mixed alkali niobate coatings for piezoelectric micro-devices [5], and solution-processed thin films transistors based on oxide heterojunctions [6], this special issue is a perfect representation of the breadth and impact of this dynamic, multidisciplinary, and impactful research field.…”