High entropy metal oxide/TiO2 nanocomposite for electrocatalytic overall water splitting

Here, high entropy metal oxide (HEMO) containing five elements (In, Co, Ni, Fe, and Zn) was loaded onto titanium dioxide (TiO2) and explored its electrochemical properties for overall water-splitting in alkaline media (1 M KOH). Here, we confirmed that HEMO-TiO2 nanocomposite boosts oxygen evolution reaction (OER) via lattice oxygen participation. Electrochemical investigations revealed that the HEMO-loaded TiO2 showed remarkable electrocatalytic properties for OER. The electrocatalyst demonstrated high performance for OER with low overpotential (336 mV @ 10 mA cm- 2), small Tafel slope (56 mV dec- 1), and high stability over 20 h. Moderate hydrogen evolution reaction (HER) performance was achieved for the HEMO-TiO2 nanocomposite regarding overpotential (191 mV @ 10 mA cm- 2) and Tafel slope (121 mV dec- 1) with high stability over 20 h. The HEMO-TiO2 based water-splitting device exhibited a low voltage (1.71 V) to reach 10 mA cm- 2. Notably, the modified interface at an electrode/electrolyte effectively alters the active sites and boosts the electronic transfer, leading to enhanced splitting efficiency. This study opens a new route for realistically creating heterogeneous interfaces to increase their electrochemical performances, which may help to speed up the progress of nonprecious catalysts for water splitting.