Abstract:

In order to develop green synthesis of silver nanoparticles (AgNPs) and their catalytic reductions for organic dyes, the Eucommia Eucommia extract was selected as reducing and capping agent for AgNPs green synthesis, and catalytic reduction on Direct Orange 26 were conducted. It is revealed that AgNPs solution synthesized using Eucommia Ulmoides extract shows an intense peak at 436 nm in the UV-Vis spectrum, and the average diameter of AgNPs in the solution is the solution is around 40 nm measuring by the laser particle size analyzer. Catalytic reductions of Direct Orange 26 with NaBH4 and AgNPs were conducted. Without the existence of AgNPs, nearly no reduction for the Direct Orange 26 is carried out within 30 min. While, up to 93.2% of Direct Orange 26 is degraded after 30 min with the addition of AgNPs. Furthermore, the catalytic performance of AgNPs synthesized at different reaction temperatures shows variations on particles size distributions and catalytic performances. AgNPs synthesized at relative low temperature showed higher catalytic activity. After reductive degradation, azo groups in the dye molecular are broken, which also destroyed the macromolecular structure of Direct Orange 26.

Key words: Eucommia ulmoides silver nanoparticle, catalytic performance, Direct Orange 26, reductive degradation