2D CeO2 and a Partially Phosphated 2D Ni-Based Metal-Organic Framework Formed an S-Scheme Heterojunction for
Haiming Gong1, Youji Li2, Hongying Li1
1School of Chemistry and Chemical Engineering, Ningxia Key Laboratory of Solar Chemical Conversion Technology, Key Laboratory for Chemical Engineering and Technology, State Ethnic Affairs Commission, North Minzu University, Yinchuan 750021, P. R. China.
Abstract:
Here, an S-scheme heterojunction was constructed on the basis of the modification of a Ni-based metal-organic framework (Ni-MOF) by different in situ treatment strategies. First, NiS2, NiO, and Ni2P were derived in situ on the surface of Ni-MOF through surface sulfonation, oxidation, and phosphatizing treatments. They can efficiently accept the electrons from the conduction band of Ni-MOF as the trap centers, thus improving the hydrogen production activity. Additionally, phosphatizing makes the electronegativity of Ni-MOF/P stronger than that of the original Ni-MOF, which can enhance the absorption of protons, thus promoting the hydrogen evolution reaction. Next, the S-scheme heterojunction was successfully built by the coupling of 2D CeO2 with Ni-MOF/P. The maximum hydrogen production rate of the hybrid catalyst (6.337 mmol g-1 h-1) is 14.18 times that of the untreated Ni-MOF due to the full utilization of photo-induced electrons. Finally, the probable hydrogen evolution mechanism was proposed by analyzing a series of characterization results and by the density functional theory (DFT) calculation.
