Chemical Etched Layered Double Hydroxides For Enhancing The Oxygen Evolution Reaction

Water splitting is promising for energy storage and conversion,but the sluggish oxygen evolution reaction（OER）hinders its wide application.The search for efficient and low-cost electrocatalysts for oxygen evolution has been pursued owing to their significance for green energy generation and storage.Noble metals and their oxides have seriously impeded their large-sacle applications because of their scarcity and high cost.Layered double hydroxides（LDHs）have been proposed as the most pro mising alternatives due to their unique layered structure and good intrinsic OER activity.Layered double hydroxides based materials are promising for the OER to improve this weakness.However,the wide application of LDHs is limited by their electronic properties and active sites.Chemical etched LDHs is used to optimize the structure and electronic properties for enhancing oxygen evolution reaction.The detailed research contents are as follows:1.Our work realized the desired product using a simple and effective method where HNO₃ was added to the LDHs suspension for etching,which results in the generation of multiple vacancies and optimization of structure.This can increase the disorder,improve the electronic conductivity and tune the surface propert ies.The XAFS data and TEM images provide strong evidence that multiple vacancies are formed after acid etching,resulting in the enhancement of the OER catalytic activity.Meanwhile,LDHs nanosheets which become thinner and smaller after acid etching exposure more active sites.This study not only demonstrates the key role of multiple vacancies for superior electrocatalysts,but also opens up a simple route to optimize the electronic structure and surface properties for advanced electrocatalytic performanc e in the future.2.Based on the bulk form and poor intrinsic conductivity,LDHs with rich defects and hierarchical structure was obtained by a simple and efficient hydrothermal method which use glycol.The thinner and smaller nanosheets,as well as the hi erarchical structure,tune the morphology and structure,exposure more active sites,and facilitate the electron transport.Moreover,a large number of defects are generated,which optimizes the electronic structure and improves the catalytic activity of o xygen evolution.After the hydrothermal reaction,the LDHs with rich defect s and hierarchical structure showed a very low onset potential of oxygen evolution,which achieved a great improvement in the catalytic performance of oxygen evolution.In addition,the LDHs with rich defects and hierarchical structure has a small Tafel slope,further proving that the introduction of defects improves the catalytic performance of oxygen evolution reaction.The method of tuning the structure and electronic properties b y defect engineering in this work will open a door for design and optimization of advanced catalysts in the future.