Synthesis of Ni2+–Al3+–LDHs with flower-like morphology assembled from an ultrathin platelets structure: Phenomenon of enhanced photocatalytic performance

This study was initiated to explore a method for producing higher photocatalytic performance in layered double hydroxides (LDHs) through the preparation of ultrathin nanosheets, which would generate higher surface area (SA). Herein, a method is detailed for fabricating Ni2+-Al3+-LDHs with flower-like morphology assembled from an ultrathin nanosheet (Ni2+-Al3+-LDHs-U) employing a low temperature-reflux method together with a surfactant. The resulting products’ structures, morphologies, porous properties, and bandgaps were investigated using a series of characterization techniques, which confirmed the formation of Ni2+-Al3+-LDHs-U with an ultrathin nanosheet structure (4–8 nm) and large SA (151 m2/g), which were nearly three times greater than the Ni2+-Al3+-LDHs comprising a thick nanosheet structure (50 nm, Ni2+-Al3+-LDHs-T). In addition, the bandgaps of these new Ni2+-Al3+-LDHs-U materials were 5.11 electron volts lower than the Ni2+-Al3+-LDHs-T material (5.26 eV). These flower-like morphology assembled from an ultrathin nanosheet exhibited a greatly enhanced light response that utterly decomposed methyl orange and Rhodamine B in water, which represented far better photodegradation under similar conditions compared to the thicker Ni2+-Al3+-LDHs-T and thicker Ni2+-Fe3+-LDHs-T. The increased photoreaction efficiency was explained by higher SA and catalytically active sites of the experimental product.