Facile fabrication of Zr₂Ni₁Cu₇ trimetallic nano-alloy and its composite with Si₃N₄ for visible light assisted photodegradation of methylene blue

Novel Zr₂Ni₁Cu₇ trimetallic nano-alloy (TNA) and Zr₂Ni₁Cu₇/Si₃N₄ trimetallic nano-alloy composite (TNAC) have been successfully prepared by facile microwave reduction method. The synthesis of TNA and TNAC was ascertained by characterizing them by using various techniques such as SEM, TEM, XRD, EDX and FTIR etc. The EDX shows the presence of all constituents in TNA and TNAC. The XRD study demonstrated the crystalline and semi-crystalline nature of TNA and TNAC. The optical band gap study revealed that TNAC (2.47 eV) has lower band gap then TNA (2.54 eV). The visible light photocatalytic activity of Zr₂Ni₁Cu₇TNA and Zr₂Ni₁Cu₇/Si₃N₄ TNAC has been successfully utilized for the photodegradation of methylene blue (MB). The presence of H₂O₂ has been found to influence the photodegradation rate. Photodegradation results presented that maximum degradation was observed in the presence of H₂O₂ and Zr₂Ni₁Cu₇TNAC (92%). Scavenging activity has revealed that the hydroxyl radicals were the major reacting species. These species successfully degraded the MB into various intermediates that has successfully been determined by the LC-MS. Kinetic studies indicated that the degradation of MB by Zr₂Ni₁Cu₇ TNA and Zr₂Ni₁Cu₇/Si₃N₄ TNAC followed pseudo-first-order kinetics.