Coral like gadolinium doped hematite nanostructure as stable and robust electrocatalyst for oxygen evolution water splitting

Due to the slow four-electron transference, the electrocatalytic oxygen evolution reaction (OER) is less effective at water splitting. Therefore, it is imperative to fabricate OER electrocatalysts that are highly active, durable, and scalable. Using in-situ hydrothermal growth, we preliminary grow hematite, and further gadolinium is doped on the already prepared iron oxide (Fe2O3) catalyst layer on the exterior of nickel foam (NF). This is done to produce a coral-like structure in three dimensions. According to electrochemical studies, the optimized Gd-Fe2O3 catalyst outperforms electrocatalytic OER catalysts as it requires only 245 mV to achieve 10 mA/cm2 current density, has a smaller Tafel slope (48 mV/dec) and is stable (10 mA/cm2 @50 h). The enhanced electrocatalytic performance results from coral-like three-dimensional shape that exposes more active sites and higher surface area. Future nanostructured novel catalysts for OER can be intelligently designed using the simple method employed in this study.

Automated summary

In this study, an in-situ hydrothermal growth method was used to preliminarily grow hematite on the already prepared iron oxide catalyst layer on the exterior of nickel foam, and gadolinium was further doped to form a three-dimensional coral-like structure. The optimized Gd-Fe2O3 catalyst shows excellent electrocatalytic performance in the oxygen evolution reaction, requiring only 245 mV to achieve a current density of 10 mA/cm2, with a smaller Tafel slope (48 mV/dec) and stability (10 mA/cm2 @50 h). The enhanced performance is attributed to the coral-like three-dimensional shape, which exposes more active sites and a higher surface area. Future nanostructured catalysts for OER can be intelligently designed using the simple method employed in this study.