Heterostructure interfaces and dimensionally transformed GaO/ZnO nanostructures for room-temperature hydrogen gas sensors

This work demonstrates the significant prospective of GaO/ZnO hybrid nanostructures for high-performance hydrogen gas sensing. The wavy grains of GaO support the structural transformation of ZnO nanorod into nanosheets by providing appropriate nucleation sites for ZnO growth. Compared to pure ZnO and GaO, GaO/ZnO exhibited a sixfold increase in H2 response (60% at 500 ppm), excellent selectivity towards H2 among other interfering gases, and outstanding long-term stability (retaining 98% of its initial response after 36 days). This greater performance rises from the unique morphology and different surface interactions within the GaO/ZnO hybrid nanostructure, assisting multiple adsorption sites and various hydrogen interaction pathways. Alloying effects, internal strain, and the presence of both GaO and ZnO regions within the nanosheets further contribute to enhanced sensitivity, selectivity, and stability.