Magnetic-Field-Enhanced H₂S Sensitivity of Cu₂O/NiO Heterostructure Ordered Nanoarrays

Abstract

Magnetism is a promising external intervention for gas sensitivity based on a heterogeneous interfacial structure caused by the regulation of the heterogeneous interface conductivity and the surface oxygen adsorption. In this study, Cu 2 O/NiO heterostructure-ordered nanoarrays were prepared with a two-dimensional (2D) electrodeposition in situ assembly method for H 2 S gas detection at room temperature under the action of a magnetic field. The nanoarrays were multibarrier structures with a strictly periodic structure that was greater than hundreds of microns in size. The experimental data confirmed that the response of 50 ppm of H 2 S based on the nanoarrays was improved by nearly 61% with a relatively weak magnetic field. Particularly at a low concentration (≤20 ppm), the effect of the magnetic field enhancement on the sensitivity was more obvious. We attributed the enhancement of the gas sensitivity with the magnetic field to the regulation of the Cu 2 O− NiO interface conductance and the surface oxygen adsorption. This study demonstrated that a magnetic field could significantly enhance the gas sensitivity based on heterostructures. Results of this study provide an important reference for the application of magnetism in gas detection and the design of new gas-sensitive materials.

Insights into Shape Selectivity and Acidity Control in NiO-Loaded Mesoporous SBA-15 Nanoreactors for Catalytic Conversion of Cellulose to 5-Hydroxymethylfurfural

“…The modification of NiO/PVP-HPA@SBA-15 with PVP effectively anchored the NiO nanoparticles on these samples. The ratio of the intensities of the Ni­(II) 2p 3/2 and Ni­(II) 2p 1/2 signals was approximately 2:1 with binding energies of 854.3 and 871.8 eV for NiO/HPA@SBA-15 and 856.9 and 874.8 eV for NiO/PVP-HPA@SBA-15, respectively. , Two additional lower intensity peaks at higher bending energies were attributed to the satellites Ni­(II) 2p 3/2 and satellites Ni­(II) 2p 1/2 signals (860.2 and 877.7 eV for NiO/HPA@SBA-15 and 863.4 and 882.1 eV for NiO/PVP-HPA@SBA-15). , The higher binding energy values observed in the case of NiO nanoparticles loaded on the nanoreactors compared with the values for pure bulk NiO are ascribed to the different chemical environment caused by the presence of heteroatoms in the nanoreactor skeleton. These heteroatoms acted as electrophilic centers such that they drew in electron density to produce (NiO) δ+ sites. , The partial positive charges on the (NiO) δ+ sites were partly compensated for by electron donation from the -OH groups on SBA-15.…”

“…31,32 Two additional lower intensity peaks at higher bending energies were attributed to the satellites Ni(II) 2p 3/2 and satellites Ni(II) 2p 1/2 signals (860.2 and 877.7 eV for NiO/HPA@SBA-15 and 863.4 and 882.1 eV for NiO/PVP-HPA@SBA-15). 33,34 The higher binding energy values observed in the case of NiO nanoparticles loaded on the nanoreactors compared with the values for pure bulk NiO are ascribed to the different chemical environment caused by the presence of heteroatoms in the nanoreactor skeleton. These heteroatoms acted as electrophilic centers such that they drew in electron density to produce (NiO) δ+ sites.…”

Cu2O/Co3O4nanoarrays for rapid quantitative analysis of hydrogen sulfide in blood

“…A 2D electrodeposition in situ assembly method similar to that in our previous reports 36,37 was used to synthesize Cu 2 O/Co 3 O 4 nanoarrays. The electrolytes were prepared by dissolving 0.5821 g Co(NO 3 ) 2 and 0.7248 g Cu(NO 3 ) 2 in 49.95 mL deionized water, aer which 0.05 mL nitric acid (pH = 3) was added to the 49.95 mL electrolyte to adjust its pH.…”

Enhanced Sensitivity of ZnFe2O4 Based on Ordered Magnetic Moment Induced by Magnetic Field: A New Insight into Mechanism

“…[ 19 ] Zhang and co‐workers attributed the enhancement of the gas sensitivity with the magnetic field to the regulation of the Cu 2 O–NiO interface conductance and the surface oxygen adsorption. [ 20 ] Although some scholars have paid attention to the positive role of magnetic field in the application of gas sensors, there are few studies on the regulation of gas sensors by magnetic effect. It is not known whether the action regularities of magnetic field on sensitive materials are universal.…”