"Nanocomposites and nanomaterials"

The mechanochemical synthesis of nanodispersed Bi2Mo3O12 composition
Sachuk O.V., Zazhigalov V.A., Kotynska L.Yo. 
Department of Heterogeneous Catalytic Oxidation Processes, Institute for Sorption and Problems of Endoecology of the NAS of Ukraine. General Naumov str., 13, Kyiv-03164, Ukraine. 
E-mail: Slena951@ukr.net 
Last time the bismuth molybdate Bi2Mo3O12 has been extensively studied to enhance catalytic, sorption, optical, photocatalytic and conductive properties. The mechanochemical treatment (MChT) is a promising method for synthesis of bismuth molybdate because the synthesis is carried out in the absence of a solvent, metal oxides or oxide and metal salt are used, and the process meets the needs of "green chemistry".
The complex Bi(NO3)3×5H2O/MoO3=1:1 composition was activated by mechanochemical method for 4 hours in air medium. XRD data show that MChT of Bi/Mo mixture leads to formation of monoclinic α-Bi2Mo3O12 phase with simultaneous decrease in particle sizes (L) (Table) for maximal reflex of Bi(NO3)3×5H2O. It was found that as a result of mechanochemical activation the increase of specific surface area (Table) is carried out. 
Table 
Some properties of obtained samples
Sample	Parameter	
	L, nm	SBET, m2/g	Safranin T destruction, *Kd·106s-1	
			UV	Visible light	
Initial	65	3	5.9	3.8	
After MChT	46	6	10.7	14.6	
*Kd - degradation rate constant
According to TG-DTA data the formation of new phase after activation is occurred as evidenced by the appearance of endothermic peak at 345°C that is connected with bismuth molybdate crystallization. However, the presence of endothermic effect at 147°C which is related with NO3- removal shows the presence of initial bismuth salt. That is the results demonstrate the incompleteness formation process of new phase in MChT but its formation at this treatment.
The studies of photocatalytic properties (Kd) of synthesized samples showed that the composition after mechanochemical activation demonstrates higher activity in photocatalytic decomposition of aqueous safranin T dye solution than initial sample (Table 1).