Interfacial Chemical Bond Induced Ni ₅ P ₄ /MnCdS Ohmic Junction Enhanced Built‐In Electric Field for Efficient Photocatalytic Hydrogen Evolution

Abstract The slow photogenerated carrier dynamics on the surface of photocatalyst have seriously hindered the progress of photocatalysis technology and the development of its industrial application. In this work, a Ni ₅ P ₄ /MnCdS ohmic junction with interfacial Ni─S chemical bond is constructed by electrostatic self‐assembly and hydrothermal method for highly efficient interfacial charge transfer. MnCdS nanosheets are successfully synthesized using solvothermal method and loaded onto metal rich Ni ₅ P ₄ nanoflowers. Ni ₅ P ₄ /MnCdS with atomically close contact interface through Ni─S bonds, resulting in a strong electronic coupling effect that regulates the direction of electron movement. The Ni ₅ P ₄ nanoflowers with a layered structure have outstanding porous properties, increasing the contact area with enhancing electron transfer efficiency. XPS and FTIR spectra confirmed the interfacial Ni─S chemical bond is formed. In situ XPS and density functional theory calculations (DFT) prove the successful construction of Ni ₅ P ₄ /MnCdS ohmic junction with strong electronic coupling effect, which effectively improved the charge separation and electron transfer. Consequently, the 3%Ni ₅ P ₄ /MnCdS achieved the highest hydrogen evolution rate of 25.24 mmol g ⁻¹ h ⁻¹ , exceeding the 3%Pt/MnCdS. This work provides valuable insights into the development of ohmic junctions by constructing interfacial chemical bonds.