In Situ Growth of Metal Particles on 3D Urchin-like WO₃ Nanostructures

Abstract

Metal/semiconductor hybrid materials of various sizes and morphologies have many applications in areas such as catalysis and sensing. Various organic agents are necessary to stabilize metal nanoparticles during synthesis, which leads to a layer of organic compounds present at the interfaces between the metal particles and the semiconductor supports. Generally, high-temperature oxidative treatment is used to remove the organics, which can extensively change the size and morphology of the particles, in turn altering their activity. Here we report a facile method for direct growth of noble-metal particles on WO(3) through an in situ redox reaction between weakly reductive WO(2.72) and oxidative metal salts in aqueous solution. This synthetic strategy has the advantages that it takes place in one step and requires no foreign reducing agents, stabilizing agents, or pretreatment of the precursors, making it a practical method for the controlled synthesis of metal/semiconductor hybrid nanomaterials. This synthetic method may open up a new way to develop metal-nanoparticle-loaded semiconductor composites.

Graphene-based transition metal oxide nanocomposites for the oxygen reduction reaction

“…For mono-, bi-, and multi-metal oxides supported on graphene sheets, EDX is effective for compositional determination of the nanocomposites combined with TEM or SEM. 105,106 Thermogravimetric analysis (TGA) is a widely used technique to characterize the thermal stability and the loading amount of a metal in graphene-based composites. [107][108][109] …”

Clean synthesis of Cu2O@CeO2 core@shell nanocubes with highly active interface

“…The main reason for the lack of successful hybridization is that the preformed Cu 2 O cores cannot withstand the conditions during the coating of CeO 2 in the following step (Cu 2 O could be severely etched by ammonium, which is indispensable during the CeO 2 coating process). However, recently, an important one-step synthetic strategy called 'clean synthesis' [17][18][19][20][21][22][23] inspired us to solve this problem. Herein, 'clean' means not only free of toxic raw materials, especially organic compounds, but also low-cost and low-temperature aqueous synthesis, a surface free of residues and a greatly simplified post-treatment process, which are extremely valuable for practical applications.…”

Embedding Ultrafine and High‐Content Pt Nanoparticles at Ceria Surface for Enhanced Thermal Stability

“…As detailed in the Experimental Section, the surface‐loaded sample was prepared by reacting preformed ceria intermediate nanorods (ceria/cerium hydroxide nanorods) with the K 2 PtCl 4 solution. Similar to our synthesis, this reaction has been known to load ultrafine Pt NPs on reduced oxide surfaces (Figure S3B, Supporting Information) 25, 26, 27. The encapsulated sample was prepared by simultaneously introducing K 2 PtCl 4 during the same time when ceria nanostructures were formed (Figure S4, Supporting Information).…”