Rapid One-Pot Solvothermal Batch Synthesis of Porous Nanocrystal Assemblies Composed of Multiple Transition-Metal Elements

Abstract

The ability of a rapid-heating solvothermal process to synthesize porous nanocrystal assemblies composed of the multiple transition metals was demonstrated. The rapid heating facilitated the quick formation of nascent nanocrystals to generate homogeneous mixed transition-metal oxides. Systematic studies of the synthesis of mixed-metal oxides under various experimental conditions indicated that the present simple method is suitable to develop a wide variety of binary and ternary transition-metal systems such as Co/Mn, Ni/Mn, and Co/Mn/Fe mixed-metal oxides. The products obtained from the rapid heating process were hierarchically assembled porous nanospheres composed of sub-10 nm nanocrystals, which had an extraordinarily high surface area and nano/mesopores. Electrochemical tests revealed the high catalytic ability of the porous nanocrystal assemblies in water oxidation.

Ce3+-enriched spherical porous ceria with an enhanced oxygen storage capacity

“…Additional trials were performed using oxyethylene compounds as additives because these are well known chelating reagents based on the coordination of oxygen atoms to the central metal ions of metal salts. 27,28 These trials produced cubic CeO 2 aggregates with improved porous spherical morphologies in accordance with the number of oxyethylene units (Fig. 1e-g and 2e-g).…”

Insights into the solvothermal reaction for synthesizing tin(iv) oxide porous spheres

“…The combination of high reaction temperature of 300 C and short reaction time of 10 min of our solvothermal reaction nicely leads to smaller crystallites with huge specic surface area of the resultant nanoparticles in many cases. 29,31 Trials under the similar reaction conditions were summarized in Tables 1-3.…”

Porous niobia spheres with large surface area: alcothermal synthesis and controlling of their composition and phase transition behaviour

“…36 As mentioned in the introduction, composite MARIMOs consisting of plural metal oxides have been successfully synthesized. [10][11][12][13] Herein, a one-pot and single-step technique was used to obtain TiO 2 -Nb 2 O 5 composite MARIMOs.…”

“…Both solid and hollow MARIMOs can be obtained with TiO 2 . In addition, composite MARIMOs, including CeO 2 -ZrO 2 , 10 Al 2 O 3 -TiO 2 , 11 ZnO-TiO 2 , 11 SiO 2 -TiO 2 , 12 Co/Mn oxide, 13 Ni/Mn oxide, 13 and Co/Mn/Fe oxide 13 have been prepared via the solvothermal method with tightly controllable stoichiometry. Thus, solvothermal method is a versatile approach for obtaining metal oxides with a porous spherical structure, large surface area, and nano concave-convex surface structure.…”