The obtained solution was put in a

The obtained solution was put in a 10 ml syringe with a stainless steel needle.A copper pin connected to a high voltagegenerator was inserted in the solution as a positive terminalwhereas a ground iron drum covered by polyethylene sheet served as counter electrode. The distance between the syringe needle tip and collector was fixed at 18 cm at 15 kV. The assynthesized mat of composite fiber was initially dried at 80 8C for 24 h under vacuum, and then calcined at 500 and 700 8C for 2 h in air atmosphere with a heating rate of 2 8C/min.