Substoichiometric two-dimensional molybdenum oxide flakes: a plasmonic gas sensing platform

Abstract

Two-dimensional (2D) molybdenum oxides at their various stoichiometries are promising candidates for generating plasmon resonances in visible light range. Herein, we demonstrate plasmonic 2D molybdenum oxide flakes for gas sensing applications, in which hydrogen (H2) is selected as a model gas. The 2D molybdenum oxide flakes are obtained using a grinding-assisted liquid exfoliation method and exposed to simulated sunlight to acquire its substoichiometric quasi-metallic form. After the exposure to H2 gas molecules, the quasi-metallic molybdenum oxide flakes are partially transformed into semiconducting states, thus gradually losing their plasmonic properties. The novel 2D plasmonic sensing platform is tested using different concentrations of H2 gas at various operating temperatures to comprehensively assess its sensing performance. The presented 2D plasmonic system offers great opportunities for future sensing and optical applications.

Green deposition of Pd nanoparticles on WO3 for optical, electronic and gasochromic hydrogen sensing applications

“…Different types of hydrogen sensors have been reported, utilizing catalytic, gasochromic, electrochemical, mechanical, optical, acoustic, thermal conductivity, resistance, work function and plasmon related detection schemes [2][3][4][5][6][7][8][9][10][11]. Since hydrogen detection often takes place in an explosive environment, (for leak detection or hydrogen-concentration measurements in gas streams) the use of optical and gasochromic hydrogen sensors have major advantages of being intrinsically safe nature and free of electric contacts in the sensing area [12].…”

Crystalline Molybdenum Oxide Thin-Films for Application as Interfacial Layers in Optoelectronic Devices

“…5 Furthermore, their usage has also been demonstrated to improve the stability of organic 6 and perovskite 7 solar cells, as well as of organic light emitting devices. 8 Other applications based on MoO x films, such as gas and chemical sensors [9][10][11] and storage devices such as memristive, memcapacitive 12 and Lithium-ion 13 devices were also reported recently.…”

A van der Waals Density Functional Study of MoO3 and Its Oxygen Vacancies

“…Inclusion of nonlocal bonding in the computation of MoO 3 helps with the description of anisotropic bulk properties as well as supporting the use of twodimensional sheets, belts and flakes in many electronic devices. [10][11][12][13][14][15] The thermodynamically stable phase of MoO 3 is a unique orthorhombic layered structure (Figure 1), space group Pbnm, with each layer comprising two sub-layers of MoO 6 distorted octahedra, edge-sharing along the c-axis and corner-sharing along the a-axis. The layers are bound by weak, mainly van der Waals, interactions and the separation between the layers is known as the van der Waals gap.…”