Synthesis of the silver nanoparticles by using morinda citrifolia’s roots from hot water extractand their degradation of methylene blue / Fairuza Husna Mohamad Jufly

The synthesized of the silver nanoparticles (AgNPs) by using the M. citrifolia
extract hot water (MHW) was applied for photocatalytic degradation dye.
Nanoparticles (NPs) had been synthesized by various methods which used the
toxic chemical. The objectives of this study are to extract M. citrifolia’s root using hot water and to synthesize the AgNPs for methylene blue (MB) dye degradation. Powder of M. citrifolia was added with hot water at 100 °C. The AgNPs was
prepared by mixing 90 ml of AgNO3 solution with the MHW extract heated for 15
minutes and the colour changes from light yellow to brown. The effect of initial pH of MHW, incubation time, temperature, different concentration of MHW and
AgNO3 were investigated in the formation of AgNPs. The AgNPs synthesized was analysed by using FTIR and UV-vis spectrophotometer. The application on the
photocatalytic degradation of dyes was determined by UV-vis spectrophotometer.
After exposing to solar light, the AgNPs degraded the dye nearly 96.9% after 6 hours. The intensity of absorbance peak of methylene blue (660 nm) was
decreased while intensity for AgNPs (420 nm) increased over the time. This study revealed that the MHWN have a good catalytic activity on the reduction of
methylene blue dye and can be used as an alternative method for water treatment
in future.