Speaker
Description
Nitrogen oxides (NOx) are among the most hazardous air pollutants emitted from combustion processes in mining, industrial, and transportation sectors, posing severe risks to human health and atmospheric quality. The development of semiconductor based gas sensors that combine high sensitivity with low power consumption remains a critical challenge. In this study, Pd-sensitized Co3O4/NiTiO3 nanostructured heterojunctions were synthesized via the microwave-assisted hydrothermal route, followed by wet impregnation with 0.5, 0.75, and 1 wt.% Pd. Structural, surface, and chemical-state analyses confirmed the successful formation of heterojunctions and the uniform dispersion of metallic Pd nanoparticles on the semiconductor surface. Gas‑sensing measurements revealed that the Pd sensitization significantly enhanced NOx sensing performance, with 0.75 wt% Pd demonstrating superior sensitivity and rapid response–recovery characteristics. The enhanced performance is primarily attributed to the metal–semiconductor Schottky junctions, which generate additional depletion regions and modify the local band structure at the interfaces, leading to pronounced resistance modulation during NOx adsorption. Simultaneously, Pd nanoparticles acted as efficient catalytic mediators, facilitating electron exchange via spillover effects and accelerating surface reaction kinetics, thereby enhancing sensitivity, lowering the detection limit, and enabling fast response kinetics. Importantly, the enhanced sensing activity was achieved at reduced operating temperatures, leading to significantly lower power consumption, which is an essential requirement for portable and battery‑powered sensors. These findings underscore the importance of interface engineering and energy‑efficient materials design in advancing sustainable gas‑sensing solutions for environmental and industrial applications.
| Apply for student award at which level: | None |
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