Octahedral-Like CuO/In2O3 Mesocages with Double-Shell Architectures: Rational Preparation and Application in Hydrogen Sulfide Detection.

This contribution describes a facile strategy for constructing octahedral-like CuO/In2O3 mesocages with double-shell architectures. The synthetic method included first preparation of unifrom Cu2O as an ideal self-sacrificial template and then decoration by a In2O3 outer layer through room-temperature Cu2O-engaged redox etching reaction combined with subsequent annealing process. Various characterization techniques manifested that In2O3 nanoparticles were uniformly grown on the surface of CuO mesocages, resulting in a well-defined double-shelled heterostructure. When evaluated as a novel sensing material for hydrogen sulfide (H2S) detection, the resultant octahedral-like CuO/In2O3 heterostructures exhibited obviously enhanced sensing response, lower operating temperature as well as faster response/recover speed during the dynamic measurement compared to the pristine CuO particles, which is likely related to the high-level of adsorbed oxygen concentration, resistance modulation effect, and unique microstructure of as-prepared CuO/In2O3 heterostructure.