The NH4VO3 solution was added dropwise into a 250mL flask containing 40mL of CTAB solution (0.05M) in an oil bath at 60 ◦C. Afterwards, 2mmol of Bi(NO3)3·5H2O was added into 20mL of de-ionized water and stirred for about 10 min to form a hydrolyzed white floccule.