Fabrication of Ni²⁺ incorporated ZnO photoanode for efficient overall water splitting

In this work, we present an effective and facile approach for deposition of zinc oxide, and nickel incorporated zinc oxide thin films to fabricate photoanode of photoelectrochemical cell. Incorporation of Ni²⁺ in the host ZnO matrix results in the dramatic shape evolution of the resulting films from simple bullet like structures to complex punch like microstructures with increased estimated electrochemically active surface area. In addition to the role of Ni²⁺ in structure determination, it significantly enhanced the photoelectrochemical performance by improving the charge transport properties and conductivity of the parent host matrix. This work demonstrates a move towards tailoring functional properties of the films via controlled incorporation of different ionic species. This simple incorporation scheme can further be applied to attain a variety of compositionally tunable unique structures for desired applications by judiciously adjusting precursor choices and manipulating relative concentrations of the incorporated precursors during growth.