Yes these are strong reducing agents and might be little dangrous but you can you some surface capping agents to protect the metal surface that might be helpful.

Dear Nasir Mahmood, 

Many thanks. What is your suggestion? However, I want to prepare zero state metal nanoparticles by a hydrothermal method.  

You probably can use Ethylene Glycol as capping agent. I havn't try that, have a good read before trying: http://pubs.acs.org/doi/pdf/10.1021/cg100740e

Thanks Mobin. Ethylene Glycol is able to reduce metal ions without reduction agent? Indeed, I want to, maybe I scared, use hydrothermal method without any gas generation during synthesis of metal nano particles.   

Don't know what exactly you mean but EG is a relatively strong reducing agent and it has been used to synthesis metal (zero charge) NPs through hydrothermal process. 

Many thanks Mobin Arab.