Using ALD to prepare Al2O3 of core-shell composites to improve photochemical performance

In this work, plasma-assisted atomic layer deposition (ALD) was used to coat a uniform Al2O3 film on the COF surface to prepare COF/Al2O3 composites; subsequently, silver nanoparticles were loaded by a photoreduction method to obtain COF/Al2O3/Ag core-shell composites. Electrochemical impedance spectroscopy (EIS), Mott–Schottky analysis, and photocurrent response tests were conducted on the two composites using an electrochemical workstation. The results show that the addition of the Al2O3 intermediate layer significantly reduces the interfacial charge transfer resistance, regulates the flat band potential and carrier concentration of the semiconductor, and enhances the separation efficiency of photogenerated carriers, making Ag/Al2O3/COF exhibit stronger and more stable photocurrent responses. This also indicates that intermediate layer engineering via atomic layer deposition provides a simple and efficient strategy for optimizing COF-based photoelectrochemical materials.