Template-based Surface Modification And Three-dimensional Architectured Method

Functional materials with controllable three-dimensional?3D?architectures have attracted tremendous attention due to their broad applications in Li-ion battery,supercapacitor,electrocatalysis,etc.Templated synthesis,which employs pre-existing substrates as templates to fabricate 3D architectures,is one of the most effective strategies to produce architectured functional materials.To overcome the possible incompatibility between a functional material and a substrate,surface modification processes like chemical treatment,plasma treatment,chemical vapor deposition,and layer-by-layer assembly are often required.But these processes have complex procedures,require high-tech equipment,or rely on specificities between modification reagents and substrates.Meanwhile,several facile and versatile modification methods,including the cross-linking of random copolymer,the self-polymerization of dopamine,and the assembly of catechol Fe³⁺complexes,are also applied in surface modification.The modification layers formed in these methods include abundant catechol groups?cross-linking groups in random copolymers?,which attribute to the strong adsorption with substrates.However,these organic-based modification layers are instable in acidic or alkaline environments and will significantly destroy the electrical conductivities of the original substrates.Hence,these surface modification methods are rarely applied in electrical fields?e.g.electrocatalysis and supercapacitors?,where surface modification is indispensable for generating a uniform layer of active materials on conductive substrates.To overcome these two problems,new versatile surface modification methods,which have negligible negative influence on the substrate conductivity,are highly required.Inspired by the modification mechanism of dopamine,we develop Ce⁴⁺as a powerful surface modification reagent for several kinds of substrates.Meanwhile,the modified substrates are versatile platform for fabricating architecture functional materials and applied in electrics.The main results as follows:?1?Ce⁴⁺is a facile and versatile surface modification reagent for a broad range of substrates?butterfly wings,carbon paper,nickel foam,and PET?with various structural features?from dozens of nanometers to several micrometers?because of its strong oxidizing ability and Lewis acid nature.?2?The modification yields abundant oxygen containing functional groups and discrete CeO₂ nanoparticle layers on template surfaces.The abundant defects in CeO₂ nanoparticles decrease the adsorption energy of transitional metal ions,providing effective heterogeneous nucleation sites for fabricating architectured oxide and hydroxide.?3?Through hydrothermal method,these Ce⁴⁺modified templates can be further employed to fabricate architectured functional materials with intact and smooth layers of CeO₂ nanoparticles,Ni?OH?₂ nanowires,FeOOH,nanosheets,and WO₃ nanosheets.During the hydrothermal process,the structural characteristics of the substrates are well reserved and the morphology of the nanoparticles can be regulated with suitable additives.?4?The modified nickel foam keeps a conductivity in the same order of magnitude of its original counterpart because of the retained original nickel foam surface.Compared with the FeOOH on unmodified NF,the FeOOH on Ce⁴⁺modified nickel foam shows a uniform large?area coating and lower overpotential?241 mV at 10 mA/cm²?for oxygen evolution reaction.This method will provide a powerful tool for fabricating 3D architectured materials,which are essential to avoiding nanoparticle aggregation,fully exposing active sites,facilitating mass transport,and exploring new structure-induced functions for functional materials.So,this facile and versatile strategy might have broad applications in their diverse applications,especially for electrical applications.