The "green synthesis of a natrolite zeolite/palladium nanocomposite" was proposed in 2015, by Hatamifard et al., "and its application as a reusable catalyst for the reduction of organic dyes in a very short time". "A natrolite zeolite/palladium (natrolite zeolite/Pd) nanocomposite has been successfully synthesized applying a simple in situ reduction method using an aqueous extract of fruits of Piper longum as a reducing and stabilizing agent. … The catalytic activity of the natrolite zeolite/Pd nanocomposite is excellent for organic dye reduction at room temperature and remains the same for several cycles" .