In situ formation of CeO2 coupled with hollow NiCo-LDH nanosheets for efficient photocatalytic hydrogen evolution

Abstract

Designing heterojunction hydrogen evolution photocatalysts with advanced hierarchical structures and rational compositions is crucial to achieving efficient conversion of green energy, but remains challenging. Here, a facile in situ modification strategy was developed to couple CeO₂ while forming hollow NiCo-LDH nanosheets, leading to a unique NiCo-LDH/CeO₂ nanosheet heterostructure catalyst with enhanced photocatalytic hydrogen production performance. Through experiments and dynamic simulations, the reaction process was deeply studied, confirming the formation of heterojunction rather than doped products. Surprisingly, thanks to the advantages of a hollow lamellar architecture and the presence of interfacial interactions, the hydrogen production rate of dye-sensitized NiCo-LDH/CeO₂ nanosheets under visible light irradiation reaches 4312 μmol h⁻¹ g⁻¹, which is twice as much as that of NiCo-LDH nanosheets. Meanwhile, the Ni sites in the NiCo-LDH/CeO₂ heterojunction having a smaller Gibbs free energy may act as active centers. The current work provides new insights into the rational design and construction of efficient heterojunction catalysts with hierarchical structures.