Perovskite Nanoparticle-Sensitized Ga₂O₃ Nanorod Arrays for CO Detection at High Temperature

Abstract

Noble metal nanoparticles are extensively used for sensitizing metal oxide chemical sensors through the catalytic spillover mechanism. However, due to earth-scarcity and high cost of noble metals, finding replacements presents a great economic benefit. Besides, high temperature and harsh environment sensor applications demand material stability under conditions approaching thermal and chemical stability limits of noble metals. In this study, we employed thermally stable perovskite-type La(0.8)Sr(0.2)FeO3 (LSFO) nanoparticle surface decoration on Ga2O3 nanorod array gas sensors and discovered an order of magnitude enhanced sensitivity to carbon monoxide at 500 °C. The LSFO nanoparticle catalysts was of comparable performance to that achieved by Pt nanoparticles, with a much lower weight loading than Pt. Detailed electron microscopy and X-ray photoelectron spectroscopy studies suggested the LSFO nanoparticle sensitization effect is attributed to a spillover-like effect associated with the gas-LSFO-Ga2O3 triple-interfaces that spread the negatively charged surface oxygen ions from LSFO nanoparticles surfaces over to β-Ga2O3 nanorod surfaces with faster surface CO oxidation reactions.

Layer‐by‐Layer Assembled Conductive Metal–Organic Framework Nanofilms for Room‐Temperature Chemiresistive Sensing

“…[7] Ammonia (NH 3 )i satoxic,f lammable,a nd explosive gas but utilized extensively in chemical industries,f ertilizer factories,a nd so on. [8] It is also at ypical biomarker for the detection of kidney and liver diseases [9] for breath analysis. [10] At present, realizing high sensitive and selective detection of NH 3 at room temperature (RT) is still abig challenge.Inview of its high RT conductivity of 0.02 Scm À1 (Supporting Information, Figure S6), Cu 3 (HHTP) 2 -xC were utilized to fabricate chemiresistor sensors for the NH 3 detection of high sensitivity and selectivity.Cu 3 (HHTP) 2 -xC based chemiresistor sensors (Supporting Information, Figure S1a) were tested in ah ome-made sensing system reported in our previous works (for details,s ee the Supporting Information).…”

The Growth of Ga2O3 Nanowires on Silicon for Ultraviolet Photodetector

“…Third, Ag nanoparticles play the role of electron mediators that allow electrons to migrate from the surface of Ga 2 O 3 nanowires to the O 2 through the defect states of Ga 2 O 3 . As a result, the bulk defects of Ga 2 O 3 may act as a secondary factor in the sensing mechanism in addition to the surface defects [4]. Consequently, Ag NPs significantly reduce the density of electrons of Ga 2 O 3 and improve electrical conductivity, leading to better selectivity and sensitivity.…”

“…In recent years, gallium oxide (Ga 2 O 3 ) became one of the most important materials that can operate in harsh conditions. With a band-gap of 4.8 eV, a high melting point of 1900 °C, excellent electrical conductivity, high figure of merit for high-frequency applications, and photoluminescence [4,5], it is an ideal candidate for visible-blind UV-light sensors, particularly for power electronics, solar-blind UV detectors, and devices for harsh environments [6,7]. New processes have been investigated to synthesize Ga 2 O 3 nanowires (NWs) through a bottom-up approach, which include thermal oxidation [8,9], vapor-liquid-solid mechanism [10], pulsed laser deposition [11], sputtering [12], thermal evaporation [13,14,15], molecular beam epitaxy [16], laser ablation [17], arc-discharge [18], carbothermal reduction [19], microwave plasma [20], metalorganic chemical vapor deposition [21], and the hydrothermal method [22,23].…”

Influence of Silver as a Catalyst on the Growth of β-Ga2O3 Nanowires on GaAs

“…Ga 2 O 3 has attracted the attention of scientists due to its unique properties including a wide bandgap of 4.9 eV, a high melting point of 1900 • C, excellent electrical conductivity, and both high thermal and chemical stability [1,2]. These features have led to the consideration of Ga 2 O 3 nanowires as a useful material for applications in power electronics, solar-blind UV detectors, and device applications in harsh environments [3,4].…”