A facile approach to tailor electrocatalytic properties of MnO2 through tuning phase transition, surface morphology and band structure

The band structure and surface morphology of oxide-based electrocatalysts are key factors which determine their electrochemical performance, while it is still challenging to synergistically align the band gap and tune the surface morphology through facile approaches.In this work, through designing a nanosheet-nanowire hybrid architecture with superior band gap alignment, improved oxygen evolution reaction and hydrogen evolution reaction have been demonstrated in alpha MnO2.The experimental results indicate that the K + in the solution plays an important role in the formation of MnO2 with different phases.The phase of MnO2 changed from delta to alpha, and the nanowires formed on the nanosheets with the increase of reaction time, which highly improve the surface area of MnO2.First principle calculations indicate that the phase and oxygen vacancies are responsible for the improvement of electrochemical performance.