An aminolytic approach toward hierarchical β-Ni(OH)_2 nanoporous architectures: A Bimodal forum for photocatalytic and surface-enhanced Raman scattering activity

摘要

A surfactantless, trouble-free, and gentle wet chemistry approach has been used to interpret the precisely controlled growth of β-Ni(OH)_2 with the assistance of ammonia and nickel acetate from seedless mild hydrothermal conditions. A thorough investigation of the reaction kinetics and product morphology with varied concentration of NH_3 and different reaction times suggests that a putative mechanism of dissolution, recrystallization, and oriented attachment supports the intelligent self-assembly of nanobuilding blocks. Associated characterizations (FTIR, PXRD, FESEM, EDAX, HRTEM, and Raman) have identified it to be pure β-Ni(OH) _2 without any signature of contamination. The assembled units result in porous frameworks (nanoflowers and nanocolumns) and are indeed full of communally intersecting nanopetalsanoplates with both lengths and widths on the order of micrometer to nanometer length scale. The as-synthesized material could also be used as a precursor for nanometric black NiO under calcination. The hydroxide has been found to be a potent and environmentally benign material because it warrants its photocatalytic activity through dye mineralization. Finally, Ni(OH)_2 has been photochemically derivatized with dosages of silver nanoparticles bringing a competent composite authority Ag@Ni(OH) _2, to give a full-proof enhanced field effect of prolific SERS activity. In a nutshell, these results are encouraging and fetch new promise for the fabrication of a low-cost and high-yielding greener synthetic protocol for a functional material with promising practicability.