Revealing the photocatalytic performance of the dual Z-scheme MIL-100(Fe)@Bi2MoO6/MoS2 heterojunction in the degradation of Acid Blue 92 azo dye

Bi₂MoO₆ is recognized as a promising photocatalyst for water post-treatment. However, its effectiveness is limited by rapid electron-hole recombination and poor sensitivity to visible light. In this study, a MIL-100(Fe)@Bi₂MoO₆/MoS₂ ternary composite was synthesized via hydrothermal method. Initially, a nanoflower-like Bi₂MoO₆@MoS₂ structure was synthesized, utilizing MoS₂ as a stable framework for Bi₂MoO₆ nanoflakes. This configuration enhances light absorption and increases the number of catalytic active sites. Incorporation of MIL-100(Fe) into the binary photocatalyst creates a core–shell structure that increases the surface area and reduces electron-hole recombination. The characterization techniques confirm the successful immobilization of Bi₂MoO₆ and MIL-100(Fe) on the surface of MoS₂ and the binary composite, respectively. The MIL-100(Fe)@Bi₂MoO₆/MoS₂ ternary composite exhibits superior photocatalytic activity in degrading nonbiodegradable pollutants, achieving 82 % degradation of Acid Blue 92 under visible light, compared to 40 % of pure Bi₂MoO₆. The improved photocatalytic activity is primarily attributed to the synthesis of MIL-100(Fe)@Bi₂MoO₆/MoS₂ composite, which facilitates efficient electron-hole separation and transfer. According to active radical trapping experiments, the most active reactive species identified are photogenerated O₂^•−, h⁺. A potential mechanism underlying the improved photocatalytic activity of the MIL-100(Fe)/Bi₂MoO₆/MoS₂ heterostructure has been explored and discussed based on the results of the scavenger experiments.