Hematite/M(M = Au, Pd) Catalysts Derived from Double Hollow Prussian Blue Microstructure: Simultaneous Catalytic Reduction of o- and p-Nitrophenols.

Present study deals with Hematite/M(M = Au, Pd) catalysts converted from double hollow Prussian blue microstructure (DHPM). The unique Prussian blue (PB) microstructure (MS) is prepared by template-free solvothermal synthetic route in a single step reaction. Amine functionalized silicate sol-gel matrix (SSG) has served as a structure directing agent cum stabilizer for making DHPM. Synthesized DHPM is having unique structure; hollow core and in-situ etched porous surface. Growth mechanism is explored revealed by analyzing several experimental parameters such as HCl concentration, Fe source, effect of the added EtOH, silane concentration, and role of silanes' amine groups. It is identified that the superstructure consisted of a well-aligned PB Cubes growing radially from the core of the superstructure. Metal (Au and Pd) nanoparticles (NPs) is deposited on both interior and exterior of the PB MS through galvanic displacement reaction thus metal NPs loaded Hematite phase iron oxide (α-Fe2O3) nanomaterials were derived by annealing it in air. Catalytic activities of the Hematite/M(M = Au, Pd) MS are investigated towards simultanoeus catalytic reduction of o-nitrophenol (ONP) and p-nitrophenol (PNP). Resultant Hematite/Pd MS has shown high structural stability and catalytic active sites than Hematite/Au MS, which enhances the catalytic properties for the simultaneous catalytic reduction of both nitrophenols.