MOF template catalysts derived dual heterojunction sensitization: PdO@ZnWO4–WO3 composite nanofibers with enhanced acetone sensing properties

• Published in: Journal of alloys and compounds 2025-01, Vol.1010, p.178086, Article 178086
• Main Authors: Sun, Jie, Tao, Yulin, Zhang, Jinniu, Gao, Jianzhi, Lu, Hongbing, Sun, Yaojie
• Format: Article
• Language: English
• Subjects: Gas sensors; MOF; Multiple heterojunctions; Nanofibers; WO3
• ISSN: 0925-8388
• DOI: 10.1016/j.jallcom.2024.178086

The construction of multiple effective heterostructures and the catalytic effects of noble metal catalysts can significantly enhance the sensing response, accelerate response and recovery rates, and reduce the operating temperature of metal oxide-based gas sensors. In this study, metal–organic framework (MOF)-derived PdO@ZnWO4–WO3 (PZW) dual heterojunction nanofibers (NFs) were constructed using Pd@ZIF-8 as a novel catalyst loading platform to effectively sensitize porous WO3 NFs. The PZW-2 NFs prepared with an optimal volume of 2.0 mL Pd@ZIF-8 solution possessed enhanced resistance modulation capacity and reduced sensing reaction activation energy. Consequently, the PZW-2 NFs demonstrated excellent sensing properties characterized by high acetone responses (Ra/Rg = 24.6–20 ppm) and short response/recovery times (4 s/6 s). The PZW-2 NFs also exhibited good selectivity and stability towards acetone. These improved sensing performances were attributed to the synergistic interactions in several aspects, including the generation of dual heterojunctions, the catalytic effects of PdO nanoparticles, and the unique porous nanofiber structure with a high specific surface area. This work provides a new strategy to fabricate noble metal@MOF-derived dual heterojunction NFs with high gas-sensing performances. [Display omitted] •MOF-derived PdO@ZnWO4–WO3 (PZW) dual heterojunction NFs were constructed.•The sensing reaction activation energy of PZW-2 NFs was decreased.•The PZW-2 NFs showed a high response and short τres/τrec (4/6 s) to 20 ppm acetone.•Multiple heterojunctions were formed between PdO, ZnWO4, and WO3 nanoparticles.•The acetone sensing enhancement mechanism of MOF-derived PZW-2 NFs was discussed.