Non-Hydrothermal Synthesis of Cu(I)-Microleaves from Cu(II)-Nanorods

Abstract

Simultaneous transformation of structural morphology, material dimension and oxidation state of Cu (II)-nanorod was achieved with 3-(Triethoxysilyl)propylamine, (APTS) and 4-nitrobenzaldehyde (4-NB) under non-hydrothermal condition. Morphology of the modified Cu(I) material was found to resemble with the leaf of colocasea. Conversion of a Cu(II) based nono-material to a Cu(I)-based micro-material was confirmed from EPR, MAS- NMR and cyclic voltametric (CV) study. BET-surface area, Raman signal intensity and thermal stability of the Cu(I)-microleaf was greatly enhanced due to presence of Cu-O−Si linkage. Both the Cu(II) and Cu(I) material were found to be effective catalyst systems for nitro-aldol reaction as well as catalytic oxidation of methylene blue (MB) dye in presence of H2O2. High %yield (>90 %) of nitro-aldol product was obtained with both the catalyst. Catalytic reaction under microwave irradiation was found to bring substantial decrease in reaction time. Cu (II)-material was however not recyclable because of its soft nature. While the Cu(I)-microleaf was recycled upto four consecutive cycles. These materials were found to degrade methylene blue dye within 20 min in presence of H2O2 but in absence of light. Dark phase catalytic oxidation of MB was monitored both via UV-vis and cyclic voltametric study.