Metal precursor solution

Metal Precursor solution Template Solidification gelation Template removal Crystal phase Properties and application s Ref. 

Metal Precursor solution Template Solidification gelation... 

In order to produce a three-dimensionally ordered macroporous structure, the metal precursor solution should fulfil the following criteria (1) Sufficient metal should be present in the voids to form a macroporous wall, and the metal concentration should therefore be high. (2) Reactivity of the metal precursor should be mild so that it can infiltrate the voids. If the metal precursor reacts with a functional group on the surface of the template or moisture in the air before it infiltrates the voids, an ordered porous structure cannot be obtained. (3) The metal precursor should be solidified in the voids before the template is removed and the produced... 

Metal Precursor solution Template Solidification Template removal Crystal Phase " Properties and application Ref. 

The synthesis methods used for the preparation of carbon supported PtRuMo nanoparticles could be classified as adsorption of metal colloids onto the carbon surface, or impregnation of carbon support with metals precursor solution. Additionally, the incorporation of the metals has been carried out in a (1) one step method or with simultaneous incorporation of the three metals, and in (2) two step methods or sequential incorporation of Mo and PtRu nanoparticles ... 

In the case of metals supported on inorganic gels, it is sometimes possible to find a salt of the desired metal which is soluble in the initial sol-gel solution whose solvent most often is an alcohol [136, 138, 145]. It is also possible to realize a dissolution of the metal salt in an adequate solvent and to add that metal precursor solution to the sol-gel solution [9, 16, 17, 143]. The preliminary dissolution of the metal salt in the water which will be used to hydrolyze the support precursor alkoxyde is often encountered [14, 15, 111, 112, 137, 139, 144]. 

Another strategy to fill the inner cavity of CNTs is the use of anodic aluminum oxide (AAO) template. First, an AAO template is synthesized and the CNTs selectively grown in the channels by CVD, permitting CNTs with uniform diameter and length. Next, the metallic precursor solution is introduced in the CNTs, followed by a calcination/reduction process to produce the NPs [133-136]. Finally, the AAO template is dissolved in NaOH and the NPs confined inside CNTs can be recovered. Even if this method produces uniform CNTs it suffers of scale-up difficulties. 

In summary, the wet chemistry method has proven extranely versatile in confining a plethora of different NPs inside the CNT channels. This strategy allows selective introduction of metallic precursor solutions or preformed NP suspensions in CNTs through playing with experimental parameters such as the nature of the solvent, ultrasonic and extended stirring, introduction of selectively washing... 

Abstract Silver, palladium, and rhodium nanoparticles were prepared by heterogeneous nucleation in the interlamellar space of a layered kaolinite support. Disaggregation of the lamellae of nonswelling kaolinite was achieved by intercalation of dimethyl sulfoxide. The kaolinite was suspended in various metal precursor solutions and the adsorbed metal cations were reduced with NaBH4 The diameter of the silver particles (4-10 nm) prepared in this way depends on the initial Ag" " concentration. Palladium and rhodium particles were stabilized by polymers and by the lamellae of kaolinite. The effect of the molecular mass and the concentration of the polymers on the size of the particles... 

Many reduction methods can be employed for production of the desired library. For instance, metal reduction by H2 atmosphere is largely utilized for the s)mthesis of catalysts and can be applied in the preparation of the catalyst library. An example of this approach can be obtained elsewhere in the literature [114]. Briefly, small amounts of the metal precursor solution are deposited at defined stoichiometric proportions onto a sheet of conductive support (carbon paper, carbon cloth, etc.) (Figure 15.7) and are reduced to the corresponding metal under hydrogen atmosphere at high temperature. The arrays can be prepared manually, by using micropipette [114] or an ink jet printer [115]. 

The sonochemical method is similar to the precipitation process, using a metal precursor solution (ionic), a reducing agent, and a compound that prevents agglomeration which is a molecular stabilizer and/or a support. 

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