Photocatalytic Degradation of Methylene Blue, Rhodamine B, Methyl Orange and Eriochrome Black T Dyes by Modified Zno Nanocatalysts: A Concise Review

The rapid expansion and development of industrial sectors and corridors pose a significant threat to the world today owing to the deteriorating air quality resulting from the release of harmful and toxic gases into the atmosphere. To combat and tackle air pollution, reliable and precise sub-ppm detection of these gases is highly desirable for human safety and the environment. For a gas sensor to perform its level best, the choice of nanomaterials is a critical factor that can significantly impact the robustness, stability, cost-effectiveness, sensitivity, and selectivity of the sensing device. Molybdenum trioxide (MoO3), as an n-type semiconducting metal oxide, has been rated as a research hotpot material in recent years due to its utility in a wide range of important technological applications. Owing to the advancement of synthetic techniques, it has been made possible to explore numerous novel nanostructures and integrate them into smart gas sensing devices. In this quest, this review is an effort to highlight the various nanostructures of MoO3 and the influence of these morphologies on the gas sensing performance. A detailed morphological overview of pristine MoO3 nanomaterials ranging from one-dimensional (1-D) to three-dimensional (3-D) nanostructure formation, followed by the preparation of different heterostructures including MoO3/metal oxides (p-type and n-type), MoO3/noble metal decoration, and MoO3/2D materials in the thematic domain of gas sensing, has been presented. Finally, a future outlook on the further progress of MoO3 gas sensors based on the current scenario is also suggested.

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Advances in the designs and mechanisms of MoO3 nanostructures for gas sensors: a holistic review

Synthesis and Characterization of ZnO/CuO Nanocomposites as an Effective Photocatalyst and Gas Sensor for Environmental Remediation

ABSTRACT In this work, we have successfully fabricated Sr-doped porous LaFeO3 samples via sol–gel method. The results reveal that Sr2+ cation is effectively doped into LaFeO3 crystal lattice substituting La3+ cation. The visible light catalytic performance of the materials was evaluated by the degradation of 2,4-dichlorophenol (2,4-DCP) and Rhodamine B (RhB). The amount-optimized Sr-doped porous LaFeO3 sample exhibited outstanding visible-light catalytic performance for the degradation of the model pollutants compared to the porous LaFeO3 alone. The enhanced performance was accredited to the enlarged surface area, absorption extension via the surface states of the introduced Sr2+ below the conduction band bottom of LaFeO3, and promoted charge carrier’s separation as confirmed by various experiments. Experiments of radical trapping reveal that •OH species are dominant intermediate oxidants involved in the oxidation of 2,4-DCP and RhB over the optimized sample. This research will provide new routes for environmental remediation based on the LaFeO3 semiconductor.

https://www.tandfonline.com/doi/pdf/10.1080/17518253.2022.2112093?needAccess=true

High-performance visible-light active Sr-doped porous LaFeO3 semiconductor prepared via sol–gel method

“Fe3+ modified zinc oxide nanomaterial as an efficient, multifaceted material for photocatalytic degradation of MB dye and ethanol gas sensor as part of environmental rectification”

In this experiment we studied morphological, structural and gas sensing properties of the In2O3-α-Fe2O3 nanocomposite films prepared by mechanical mixing. Iron oxide (α-Fe2O3) was prepared by co-precipitation method. We added 1 wt%, 3 wt%, 5 wt% and 7 wt% of In2O3 in synthesized iron oxide by mechanical mixing. Films of In2O3 additive and iron oxide were prepared using screen printing method. XRD study was employed to find out content and structure of the films. SEM analysis was carried out to understand film morphology. EDS analysis was carried out to understand elemental constituents of the films. Static gas sensing apparatus was used to study response of films for various gases. Properties like sensitivity, selectivity, response and recovery time were calculated. Petrol vapor sensors are not reported yet. At 250 °C these In2O3-α-Fe2O3 nano-composite films showed good response of 50% for petrol vapors as compared to other four gases. We discussed probable mechanisms for gas sensing.

https://iopscience.iop.org/article/10.1088/2053-1591/aaed90/pdf

Vikas V. Deshmane

Papers

Synthesis and Characterization of ZnO/CuO Nanocomposites as an Effective Photocatalyst and Gas Sensor for Environmental Remediation

Study of In2O3 and α-Fe2O3 nano-composite as a petrol vapor sensor

Synergy of semiconductor (Hematite) & catalytic (Ni) properties enhance gas sensing behavior to NO2

Cobalt oxide doped hematite as a petrol vapor sensor

Orthorhombic molybdenum trioxide micro-planks as carbon monoxide gas sensor