Mesoporous In2O3 structures: Hydrothermal synthesis and enhanced Cl2 sensing performance

Efficient and stable low-temperature CO oxidation over Pt/In–SnO2 composite triggered by abundant oxygen vacancies and adsorption sites

In ion doping can greatly improve the active oxygen migration ability in the Pt/In–SnO₂ catalyst, which is beneficial to CO oxidation at low temperature.

Facile metal-organic frameworks-templated fabrication of hollow indium oxide microstructures for chlorine detection at low temperature

Metal oxides with the hollow microstructure by the facile synthetic strategy are hopeful in applications for photocatalysis, supercapacitor, and gas sensor owing to their large surface areas, porosity ratio and rich active sites. In this work, indium oxide porous hollow rods (In₂O₃ PHRs) are successfully prepared using metal-organic frameworks (MOFs) as the template. The morphology of In₂O₃ PHRs is hexagonal hollow micro-rods with a porous structure. The investigation on the gas-sensing performance reveals that the In₂O₃ PHRs sensor displays outstanding sensitivity and selectivity toward 10 ppm chlorine gas (Cl₂) at low operational temperature (160 °C). Furthermore, the In₂O₃ PHRs sensor displays a low detection limit (3.2 ppb) and short response and recovery time (38/13 s). The unique morphology and abundant oxygen vacancies are conduced to the excellent gas-sensing activities, which is benefited from the utilization and decomposition of In-MOFs precursor. In addition, the gas sensing mechanism of reducing gases and oxidizing gases is deduced in detail for the In₂O₃ PHRs sensor.

Hydrothermal synthesis and Cl2 sensing performance of porous-sheets-like In2O3 structures with phase transformation

Phase transformation (bcc-In₂O₃ to rh-In₂O₃) and high Cl₂ sensing performance of Fe doped porous-sheets-like In₂O₃.

Solution combustion synthesis and enhanced gas sensing properties of porous In2O3/ZnO heterostructures

Self-assembled porous In₂O₃/ZnO heterostructures are synthesized via a low temperature solution combustion method. An extremely high gas sensitivity can be reached when exposed to Cl₂ at 370 °C.

Template-free preparation of mesoporous single crystal In2O3 achieving superior ethanol gas sensing performance

Mesoporous single crystal In₂O₃ with high specific surface area and oxygen vacancy concentration are prepared for enhanced ethanol gas sensing performance.

DFT investigation on interaction of chlorine with In2O3 nanostructures

The structural, electronic, and adsorption properties of chlorine on pristine, tin-, aluminum-, and fluorine-substituted In2O3 nanostructures are successfully optimized and computed using density functional theory along with the B2LYP/LanL2DZ basis set. The electronic properties of pristine, tin-, aluminum-, and fluorine-substituted In2O3 nanostructures are discussed in terms of ionization potential, HOMO–LUMO gap, and electron affinity. The dipole moment and point symmetry group of In2O3 nanostructures are also reported. The structural stability of pristine, tin-, aluminum-, and fluorine-substituted In2O3 nanostructures are investigated in terms of formation energy. The adsorption properties of chlorine on In2O3 are studied and the most appropriate adsorption sites of Cl2 on In2O3 nanostructures are reported. The adsorption properties of hydrogen on In2O3 nanostructures are also investigated and inferred that In2O3 exhibits good sensing characteristics towards hydrogen. The adsorbed energy, HOMO–LUMO gap, Mulliken population analysis, and average energy gap variation are used to identify the prominent adsorption site of Cl2 on In2O3 material. The substitution of fluorine in In2O3 nanostructures enhances the Cl2 adsorption properties in the mixed gas atmosphere.

Real-time detection of chlorine gas using Ni/Si shell/core nanowires

We demonstrate the selective adsorption of Ni/Si shell/core nanowires (Ni-Si NWs) with a Ni outer shell and a Si inner core on molecularly patterned substrates and their application to sensors for the detection of chlorine gas, a toxic halogen gas. The molecularly patterned substrates consisted of polar SiO2 regions and nonpolar regions of self-assembled monolayers of octadecyltrichlorosilane (OTS). The NWs showed selective adsorption on the polar SiO2 regions, avoiding assembly on the nonpolar OTS regions. Utilizing these assembled Ni-Si NWs, we demonstrate a sensor for the detection of chlorine gas. The utilization of Ni-Si NWs resulted in a much larger sensor response of approximately 23% to 5 ppm of chlorine gas compared to bare Ni NWs, due to the increased surface-to-volume ratio of the Ni-Si shell/core structure. We expect that our sensor will be utilized in the future for the real-time detection of halogen gases including chlorine with high sensitivity and fast response.

Porous corundum-type In2O3 nanoflowers: controllable synthesis, enhanced ethanol-sensing properties and response mechanism

Porous rhombohedral In₂O₃ (corundum-type In₂O₃, rh-In₂O₃) with a morphology of uniform nanoflowers was fabricated by using a mild, facile solvent-thermal method.