Onion-Ring-like Carbon and Nitrogen from ZIF‑8 on TiO2/Fe2O3 Nanostructure for Overall Electrochemical Water Splitting

The carbon and nitrogen derived from ZIF-8 embedded in TiO2/Fe2O3 (i.e., C,N-ZIF/TiFe) nanostructures exhibit superior electrocatalytic performance toward oxygen evolution reactions (OER), hydrogen evolution reactions (HER), and overall H2O splitting. The results showed that the C,N-ZIF/TiFe nanostructure was the best catalyst in comparison to ZIF/TiFe and TiFe nanostructures toward HER and OER. These results revealed that combining the highly active carbon and nitrogen from ZIF-8 with a TiO2/Fe2O3 semiconductor enriched the overall H2O splitting. A possible OER mechanism is attributed to some groups that support the surface active site of the catalyst and adsorbent intermediate species. Finally, this inexpensive electrocatalyst was synthesized without noble metals and showed superior electrocatalytic activity and great stability with the potential to achieve ground-breaking and novel applications in fuel cells.