Morphology Control And Iron-Doping Of NiCo-Layered Double Hydroxide For Enhanced Oxygen Evolution Performance

Two-Dimensional(2D)nanomaterials have always been one of the research hotspots in nanotechnology.Compared with other dimensional nanomaterials,2D nanomaterials have significant small-sized effect,surface effect and so on.Layered Double Hydroxide(LDH)is a kind of important inorganic 2D nanomaterials,which ismainly composed of hydroxides with positive charge,intercalated anions between main layers and crystalline water molecules.LDHhas thermal stability,anion exchange capacity,memory effect and so on,and can be stripped to obtain positively charged 2D nanosheets in a dispersed state.The commonly prepared LDH is a 2D rigid nanosheet.In this paper,a Three-Dimensional(3D)spherical NiCo-LDH was prepared by a one-step hydrothermal method,and the factors affecting the morphologiesof 3D NiCo-LDHwere investigated viatuning a number of experimental parameters.At the same time,we also explored a method of synthesizing the open bowl-likedLDH in one step,and achieved certain results.Because of its unique structures and properties,LDH has important research and application value in catalytic field,especially in water electrolysis.In the comparative experiments of preparing spherical NiCo-LDH,we obtained a 2D multi-wrinkle(2DMW)nanomaterial.After physical characterization,we confirmed a new type of 2D multi-wrinkleNiCo-LDH(2DMF-NiCo-LDH)which has the characteristics of thin and multi-wrinkle surface.Chemical etching can increase the defects of LDH and the number of active sites to enhance its oxygen evolution reaction(OER)performance.The unique morphology and structure characteristics of the above-prepared 2DMW-NiCo-LDH have good application potential bychemical etch ing.Ferrous chloride is an acidic and reducing iron salt that can be used to etch multiple layers of 2DMW-NiCo-LDH.The OER performance of 2DMW-NiCo-LDH was improved after the ferrous chloride etching.The overpotential of NiCo-LDH after the ferrous chloride etching was reduced to115 mV(current density was 10 mA cm-2).The slope of the corresponding Tafel plot was also reduced from 137 mV dec-1 before etching to 50 mV dec-1 after etching,and 2DMW-NiCo-LDH also showedwell I-t stability at the same time.