Preparation Of Copper Oxide And Its Carrier Transport Behavior And Active Site Characteristics

Due to its unique photovoltaic effect,semiconductors are widely used as catalysts in the fields of water oxidation and photogenerated cathodic protection.Semiconductors as catalysts can change the reaction path,reduce the activation energy of the reaction,and reduce the energy consumption and cost required for energy preparation.It is the material basis for preparing new energy.There is an urgent need to develop a stable and highly active catalyst made of earth-abundant elements to reduce dependence on precious metals.Copper oxide semiconductor materials have been extensively studied due to their advantages of low cost,high abundance,and extensive redox characteristics.However,it also has problems such as low self-conductivity,fast photogenerated carrier recombination,large oxygen evolution potential,and insufficient understanding of intrinsic active sites.In this paper,a simple anodizing method and electrodeposition method are used to synthesize electrode materials with a variety of different microstructures to reduce the internal resistance of the material,improve the separation of carriers,reduce the recombination probability,promote surface dynamics,identify Increase the active site,and conduct catalytic performance research and corresponding mechanism analysis through a variety of characterization methods.（1）The n-type nanostructured cruciate flower-like Cu₂O@Cu thin film was deposited on the conductive glass by controlling the p H of the deposition solution.The results show that the morphology plays an important role in the electronic and optical properties of the film.The mechanical energy introduced during film growth and the synergistic effect of surface plasmon resonance with the proper amount of Cu generated on the surface promote the separation and migration of carriers.304SS has a maximum negative potential shift of 179 m V under light and a maximum instantaneous photocurrent density of 0.12 m A·cm^-2,providing the best photogenerated cathodic protection.（2）By controlling the deposition potential,the n-type nanostructured cruciate flower-like Cu₂O@Cu thin film was deposited on the conductive glass,and the effect on the electronic structure and optical properties of the thin film was explored.The results show that the band gap structure is not affected by the deposition potential.The obtained Cu₂O@Cu--0.2 and Cu₂O@Cu--0.3 films were coupled with 304SS for photogenerated cathodic protection test.It was found that 304SS had a maximum negative potential displacement of 160 m V and a maximum instantaneous photocurrent density of 0.132 m A·cm^-2under light,but Cu₂O@Cu--0.3 film has lower recombination probability and recombination rate,and has higher stability.It shows that the deposition potential is-0.3 V,and the generated Cu₂O and Cu clusters have the most suitable crystallinity combination to provide the best photogenerated cathodic protection.（3）Through a simple two-step anodizing method,three-dimensional nanorod-shaped Cu（OH）₂/Cu and petal-shaped CuO/Cu electrodes with good mechanical strength and good electrical contact were prepared on copper foil.Linear scanning results show that the oxygen evolution overpotential of the CuO/Cu electrode current density of 10 m A·cm^-2only needs 440 m V,which shows a high catalytic activity.Further research found that the CuO/Cu electrode exhibited a specific surface area of1.966 m²/g and a wetting angle of 10°.Compared with the Cu（OH）₂/Cu electrode,the CuO/Cu electrode has a larger specific surface area and more a small wetting angle can maximize the contact area of the electrode material and the electrolyte,reduce the interface adsorption energy,and promote ion exchange,thereby showing stronger catalytic activity than Cu（OH）₂/Cu.Through real-time in-situ electrochemical Raman component analysis,when oxygen evolution reaction occurs,in addition to the characteristic peak of the electrode material itself,a new 603 cm^-1Raman peak related to water oxidation is generated as the active site of the catalytic substance for electrochemical water oxidation.