ABSTRACT
The ultrafine grain size of metal and semiconductor based materials (< 50 nm) has created an enormous interest in virtue of the optical, electrical, chemical and magnetic properties it conveys to them [1]. Several chemical routes to fabricate these nanoscale materials, as for example, the coprecipitation [2] the precursor concept [3] and the colloidal approaches [3,4], have been employed. Material transformation through reactions using chemical precursors can readily produce nanostructures in bulk quantities. One of the targets in tailoring novel materials is the way of arranging individual transition metals to form a cluster-like one. Recently, an alternative process has been developed which takes advantage of the reactivity of the transition metal carbonyls in solvents to tailor ruthenium based chalcogenide cluster-like materials [5]. Using this latter approach, nanoscale semiconducting MoSe2 material has also been synthesized [6]. Furthermore, the promotion of photoinduced charge separation to enhance the efficiency of photocatalytic reactions has been, for example, performed using noble metals such as platinum or gold deposited on semiconductor nanoclusters [7]. The development of heterogeneous photocatalysis, based on nanosized, nanostructured, or nanoparticulated semiconductor materials has now been placed in forefront [8]. Very recently we have synthesized novel materials based on transition metal compounds (within cluster or framework structures) in colloidal form [9].
