Passivated nanosized metal

Several works have been published on the preparation of sulfides from inorganic compounds. Table 11-1 lists some metal sulfides prepared by colloidal chemical processes. Compared with the sol-gel preparation of GeS films via route C, these metal sulfides are more stable than their oxides. Usually, nanosized metal sulfide particles were used to make sulfide films and bulk gels. Malier et al. (1998) reported the preparation of concentrated sols and transparent stiff gels of 11-Vl semiconductor nanocrystals. Sol stabilization and gelation control are achieved through successive passivation and depassivation of the surface of the nanocrystals, which are complexed with thiols. Thin films, as well as monoliths, could be prepared in this way. 

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