with silver nitrate (99%) and deionized water. Then ammonium hydroxide (25%) was added into the solution to make it be turbid, continued until it being clear again. At the moment we get the solution A. The solution B was prepared with formaldehyde (38%), ethyl alcohol and deionized water which are 11 mL/L, 950 mL/L and 39 mL/L, respectively. Then solution A was added to solution B in the same volume quickly. Wool fabric was put into the mixed solution with the bath ratio of 1:50 and stirred for 20 min. After plated, the samples were rinsed and dried to get the final product.