Preparation And Investigation Of Layered Double Hydroxide Nanoring

Hollow inorganic micro-/nanostructures have aroused increasingly comprehensive attention in virtue of advantageous properties together with prosperous applications in diverse fields.Among multifarious hollow architectures,ringlike nanostructure derived from two dimensional(2D)substrates has currently emerged as an intriguing research hotspot to be explored for not only fundamentally scientific interest but also technological utilizations.Compared to conventional hexagonal nanosheet,LDHs with a typically ringlike construction inherently possess larger surface areas,higher chemical accessibility as well as more active sites,which are conducive to facilitating electrochemical catalytic performance of LDHs since electrochemical reactions typically occur on the surfaces of catalysts.Nonetheless,nearly rare synthetic route with respect to preparing LDH nanorings has been reported in addition to our previous work up to now.It is thus imperative yet challenging to develop a simple and inexpensive strategy to synthesize LDH nanorings effectively.To address the above issues,correspongding research efforts and accomplishments are listed as follows:1.By means of selective etching/dissolution of less stable elements(amphoteric Al species,for instance)via a relatively high concentration of alkali solution,small holes ranged from atomic size to nanoscale randomly occurred on the planar surface of the specific LDHs.Enlightened by the above progresses,we demonstrate the rational design of a novel ring-like LDH structure based on the etching of metals during the growth process via a facile urea hydrolysis method.Fortunately,MgAl LDH nanoring was successfully prepared by optimizing the synthetic conditions.And by tracing the morphologic evolution process,we illuminated relative mechanism for the fabrication of nanoring.Moreover,CoAl LDH nanoring and NiFeAl nanoring can be formed in the same way as well,which paves a novel route for fabricating Al-contained LDH efficiently and controllably.2.By taking CoAl LDH as an example,we use the supercapacitance test,OER and ORR as reaaction probes to study electrochemical properties of ring-like LDHs.And the prepared CoAl LDH nanoring shows improved electrochemical catalytic performances with onset potential of 0.88 V(RHE).The larger amount of exposed active sites resulted from nanoring structure contribute to the enhanced electrocatalytic performances of CoAl LDH nanoring.