Constructing Z-scheme heterojunctions of Zr-MOF/g-C3N4 for highly efficient photocatalytic H2 production under visible light

Abstract

The construction of heterojunction photocatalysts is an effective strategy to improve photocatalytic activity. Inspiringly, this is studied by the successful fabrication of new composites of a robust Zr-MOF and low-cost g-C₃N₄via a simple method of mechanical grinding followed by low-temperature heating. The synthesized composites exhibit characteristics of wide-range visible-light absorption, good long-term stability and significant photocatalytic hydrogen production. The optimal H₂ production rate of the Zr-MOF/g-C₃N₄ (5.0 wt%) heterojunction was 1.252 mmol h⁻¹ g⁻¹, which was 41.7 and 15.7 times higher than that of pure Zr-MOF and g-C₃N₄, respectively. The Z-scheme charge transfer mechanism in Zr-MOF/g-C₃N₄ effectively improves charge separation and maintains its high redox ability, thus greatly enhancing photocatalytic hydrogen production activity. This study presents the rational fabrication of heterojunctions for photocatalytic applications and also provides new high-performance and low-cost MOF/g-C₃N₄ photocatalysts for H₂ production.