Kindly, is it applicable and save to put teflon autoclave stainless steel inside traditional domestic oven for preparation of nanoparticles or standard oven is required?
The laboratory scale oven will have a better temperature controller and less thermal gradient than that of domestic (kitchen) oven. If you have a way of controlling the temperature of your autoclave then you can use a kitchen oven. You can save money but if it is safe or not - that depends on the design of autoclave.
Autoclaves are usually used at temperatures below 200 ° C for more than one hour to synthesize nanoparticles. So if you can control the temperature and time with the domestic oven there is no problem in using it.