Rational Fabrication Of Three-dimensional Transition-metal-based Electrocatalysts Via Interfacial Reactions For Advanced Water Splitting

Electrocatalytic water splitting is one of the most ideal and effective way to produce hydrogen.However,it is always suffered from sluggish reaction kinetics due to the multistep proton coupled electron transfer process.Therefore,it is imperative to develop highly efficient,stable and cost effective electrocatalysts,expediting the reaction process at a decent rate and enhancing overall efficiency.The elctrocatalytic performance is highly related to the surface and interfical properties,component and structure of electrocatalysts.Rational design and construct highly efficient electrocatalysts are crucial for achieving the unity of catalytic performance and structure composition.In this paper,several in-situ construction methods are developed for fabricating the electrocatalysts with specific composition and hierarchical nanostructure,such as interfacial ion exchange,redox reaction,interfacial coordination self-assembly etc.Detailed contents are summarized as follows:(1)Three-dimensional porous nickel-cobalt nitride nanosheets are fabricated via facile electrodeposition and thermal annealing process under NH3 atmosphere.The high conductivity of nitride,bimetal synergetic effect and porosity structure,facilitate rapid mass transfer and charge transfer process.Benefited from the merits,porous nickel-cobalt nitride demonstrates excellent oxygen evolution and hydrogen evolution bifunctional activity and long-term stability.(2)Combining interfacial ion exchange and in-situ deposition process,a universal synthesis strategy was proposed to achieve in-situ deposition of PBA on diverse metal oxide/hydroxide nanostructures.By monitoring the pH change and UV-Vis spectrum,the reversible growth mechanism under the control of solubility product difference and solution weak acidity was revealed.Via structural-function-oriented design and anionic interface regulation,the nitride derivative demonstrates dramatically boosted bifunctional electrocatalytic activities and impressive durability for water splitting(over 1200 h).(3)In order to further simplify the preparation process of three-dimensional hierarchical Prussian blue analogues,we developed a universal strategy for in situ synthesis of diverse PBAs with delicate morphology on various metal substrates via the interfacial redox reactions and in situ deposition process.By regulating reaction kinetics regulate the growth process of PBA,which further offers new opportunities to regulate the structure and morphology.Benefited from the hierarchical structure and binder free design,the obtained oxide derivative manifests excellent oxygen evolution catalytic activity and impressive durability.(4)Via interfacial coordination self-assembly process,an universal strategy was developed for the in-situ deposition tannic acid-metal ion coordination structures on diverse nanoarrays.The strong adhesion effect of tannic acid phenolic hydroxyl group and the metal complexation ability promoted the uniform deposition.Benefited from surface modification and electronic structure regulation,TA-Fe@Ni(OH)2/NF electrode exhibits excellent electrocatalytic water splitting performance.