Metal oxide and other powders

A recent investigation has demonstrated the usefulness of ultrasonic irradiation in the preparation of delaminated zeolites, which are a particular type of modified oxides - microporous crystalline aluminosilicates with three-dimensional structures - having a greater catalytic activity than the layered structures (clays) and mesoporous catalysts. In an attempt to increase the pore size of zeolites, a layered zeolite precursor was 

Although the topic of sonoelectrochemistry will be treated in the subsequent section, it should also be mentioned that pulsed sonoelectroreduction of metallic salts gives rise to finely divided reactive metals which can be employed in organometallic synthesis see above [85]. The synthesis of nanocompounds of semiconductors such as cadmium and lead selenides can also be achieved using similar methodology [169]. 

A continuous process based on hydrodynamic cavitation can be employed to prepare a wide variety of metal oxides in grain sizes of 1 -10 nm, such as iron oxide, bismuth molybdate, perovskites, platinum-loaded zeolite, and other ceramics and superconductors [170]. The method uses a microfluidiser for mechanically generating hydrodynamic cavitation and the internal pressure of the liquid media is elevated from ambient pressure to between 1000 to 25 000 psi. 

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