线性升温条件下纳米ZnSe的生成动力学

Kinetics of Formation of ZnSe Nanocrystals under Linear Temperature Increase Condition

用非等温TG-DTG技术,在5.0、10.0、15.0和20.0K·min-14个不同线性升温条件下,研究了从配合物ZnSe(C2H8N2)制备纳米ZnSe的过程动力学.结果表明:该过程为三维扩散机理;机理函数为反Jander方程,f(α)=23(1+α)2/3[(1+α)1/3-1]-{}1,G(α)=[(1+α)1/3-1]2;表观活化能E=209.61kJ·mol-1,指前因子A=1015.7s-1,动力学方程为dαdt=1015.732(1+α)2/3[(1+α)1/3-1]-{}1exp-25211.7()T.并用结果解释了实验现象.初次报导了纳米ZnSe在420℃左右氧化为粒度低于40nm的纳米ZnO.

The kinetics of formation of ZnSe nanocrystals from the complex ZnSe(C2H8N2) has been investigated by means of non-isothermal TG-DTG at various heating rates of 5.0, 10.0, 15.0 and 20.0 degreesC (.) min(-1). The results show that the formation of ZnSe nanocrystals was controlled by three-dimension diffusion. The most probable kinetic function in differential form, and in integral form, the apparent activation energy(E) and the pre-exponential constant(A) of the process are f(alpha) = {(3)/(2)(1+alpha)(2/3)[(1+alpha)(1/3)-1](-1)}, G(alpha) = [(1+alpha)(1/3)- 1](2), 209.61 kJ (.) mol(-1) and 10(15.7) s(-1), respectively. The kinetics equation is (dalpha)/(dt) = 10(15.7){(3)/(2)(1+alpha)(2/3)[(1+alpha)(1/3)-1](-1)}exp(-(25211.7)/(T)) The calculated results are in accordance with the experiments. ZnO nanocrystal with less than 40 mn size has also been obtained from ZnSe nanocrystals.