Construction of amorphous-RuOx / crystalline-WO3 heterostructures for high-performance triethylamine sensor

The introduction of amorphous phase to form the amorphous/crystalline (A/C) interface for exposing more active sites and enhancing device performance has proven to be an effective means. In this work, amorphous RuOx clusters were synthesized by a thermal annealing method. And then amorphous-RuOx/crystalline-WO3 composite heterostructures were prepared by self-assembling to fabricate gas sensor. This A/C heterostructure-based sensor exhibits a unique hybridized phase structure with abundant phase boundaries by combining crystalline and amorphous properties, which also shows abundant unsaturated active sites and enhanced catalytic performance. The sensor based on amorphous-RuOx clusters/crystalline-WO3 nanosheets showed a good response(∼36) to 10 ppm triethylamine at 140 °C as well as a fast response time (1 s), and lower limit of detection (0.5 ppm). This work provided a high-activity and good-stability A/C gas sensors, which proved the promising future of amorphous materials in gas sensors. •The oxygen vacancy in composites was regulated by introducing amorphous-RuOx clusters.•The heterostructures were formed between the amorphous-RuOx and the crystalline-WO3.•The amorphous-RuOx/crystalline-WO3-based sensor achieves highly sensitive detection of triethylamine at 140 °C.•The materials were characterized by SEM, TEM, and XPS in a vacuum environment to analyze the associated sensitization mechanisms.