Novel synthesis of Ti-Fe2O3/MIL-53(Fe) via the in situ process for efficient photoelectrochemical water oxidation

The slow kinetics of water oxidation has become a challenge for photoelectrochemical hydrogen production. Here, a novel organic-inorganic integrated photoanode system was constructed by using MIL-53(Fe) formed during the in-situ etching process as a cocatalyst to modify Ti-Fe2O3. The photocurrent density of Ti-Fe2O3/MIL-53(Fe) reaches 2.5 mA/cm2, 10 times that of bare Ti-Fe2O3 at 1.23 V vs. RHE, and the water oxidation photocurrent onset potential shifts 105 mV negatively. Ti-Fe2O3/MIL-53(Fe) reaches 52% at 390 nm for IPCE. The excellent photoelectrochemical performance is due to iron oxide clusters boost charge separation and transfer, in-situ etching exposes more reactive sites, and the tight connection reduces interfacial resistance, which greatly accelerates the surface kinetics of Ti-Fe2O3. The in-depth understanding is provided for in-situ modification of photoanodes by metal organic frameworks in this work. & COPY; 2023 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

The slow kinetics of water oxidation is a challenge for photoelectrochemical hydrogen production. In this study, a novel organic-inorganic integrated photoanode system was constructed using MIL-53(Fe) as a cocatalyst to modify Ti-Fe2O3. The Ti-Fe2O3/MIL-53(Fe) exhibited significantly enhanced photocurrent density and water oxidation performance due to iron oxide clusters boosting charge separation and transfer, in-situ etching exposing more reactive sites, and the tight connection reducing interfacial resistance. This work provides an in-depth understanding of in-situ modification of photoanodes by metal organic frameworks.