One-Atmosphere Aqueous-Solution Synthesis of Trimolybdate Nanomaterials and the Feasibility for Mass Production

Abstract

Mass production of low-cost functional nanomaterials is an important issue for the development of nanoscience and nanotechnology. With rich structural, physical and chemical properties, polyoxometalates are important functional materials for both industrial applications and fundamental research. We presented a family of alkali trimolybdate nanowires and nanorods that were synthesized by a one-atmosphere aqueous solution method from a mixture of two solutions, one consisting of (NH4)6Mo7O24 x 4H2O and the other of Li+, Na+, K+ and Rb+ ions, respectively. This family showed clear similarities in their Raman and infrared spectra. By systematic characterizations, we have figured out a universal formula theta(m)(NH4)(2-m)Mo3O10 x nH2O (theta = Li, Na, K, Rb; m = 1,2) for this family of hydrate nanomaterials. Among them, two new phases, namely Li2Mo3O10 x H2O and Rb2Mo3O10 x 3 x 4H2O were recognized. The method was also applied to synthesizing Ag-doped trimolybdate nanowires, and the feasibility for mass production of these nanomaterials with a continuous synthesis experiment was also clear demonstrated. The results of this work offered interesting experimental data for theoretical analysis of the unique growth mechanism.

Contact Mechanism of the Ag-doped Trimolybdate Nanowire as An Antimicrobial Agent

“…It showed that, under the conditions of our experiments, the minimum concentration of Ag + ion concentration for antibacterial application was somewhere between 18 ppm and 7 ppm, a value much higher than the 1.7±0.3 ppm measured from the suspensions of Ag-doped NWs. Therefore, the results have shown that the tiny amount of Ag + ion released in aqueous solutions from the solid Ag-doped NWs is not the major antibacterial factor observed in our experiments [32,33]. The aqueous solution of Ag + ions is known as a strong antibacterial agent.…”

“…The suspension was stirred thoroughly, kept for 24 hrs and filtered with a 0.45 μm-pore filter. In the suspension the concentration of Ag-doped NWs (1 wt%) was much higher than its minimum inhibitory concentration observed previously for antibacterial effect, which was 2-15 ppm [32,33]. This setup ensured that, if Ag + ions could be released from the Ag-doped NWs, in the filtered solution one should found enough Ag + ions, and the solution should have obvious antibacterial effect.…”

“…We have followed the method reported previously to synthesize the Ag-doped trimolybdate NWs [32,33]. Basically, the Ag-doped NWs were synthesized from a mixed aqueous solution of (NH 4 ) 6 Mo 7 O 24 ·4H 2 O (purity 99.999%) and AgNO 3 (purity 99.999%) that were separately dissolved in de-ionized water.…”

“…The crystalline structure of the Ag-doped NWs is similar to the alkali family of trimolybdate NWs, namely Θ m (NH 4 ) 2−m Mo 3 O 10 ·nH 2 O (Θ=Li, Na, K, Rb; m=1, 2). The Ag-doped NWs are hard to be dissolved in solutions with pH values of 2-9, but they can be dissolved in Martin broth [33].…”

The Unique Antimicrobial Effects of Trimolybdate Nanowires

“…We have followed the method reported previously to synthesize the trimolybdate NWs [11,12]. We first examined the antibacterial effects of K 2 Mo 3 O 10 •3H 2 O, and found its unique effect on Cuyitococcus Neofonmans (Cne).…”