Broad-Range Fast Response Vacuum Pressure Sensors Based on a Graphene Nanocomposite with Hollow α-Fe₂O₃ Microspheres

Abstract

This paper demonstrates the application of a graphene–ferric oxide (hollow mesoporous α-Fe2O3 microspheres) nanocomposite for the measurement of vacuum pressure. Numerous research and industrial systems essentially require a vacuum environment, and therefore, measurement of vacuum becomes vital for their efficient functioning. The presented graphene nanocomposite vacuum pressure sensor (GnVS) is fabricated using a reduced graphene oxide (rGO)/α-Fe2O3 nanocomposite synthesized by a facile and safe hydrothermal process. This sensor has an impressive operating range spanning 9 orders of magnitude down from atmospheric pressure (103 mbar) to high vacuum (∼4 × 10–6 mbar), a remarkable sensitivity of 2 × 10–4 mbar–1, and a response/recovery time of ∼3 s, which are major improvements over the reported graphene- and rGO-based vacuum sensors. The reason behind the exceptional device performance is proposed to be a coaction of gas chemisorption on sensor surface, thermal conductivity of the sensing material, and varying van der Waals force between rGO layers. The temperature dependence of the sensor has been examined, and an appropriate temperature compensation technique is suggested. GnVS promises to bring a one-step vacuum measurement solution with its high sensitivity, repeatability, broad range, simple cost-effective design, and potential to revolutionize the vacuum sensing technology.

Multifunctional Graphene Sensor Ensemble as a Smart Biomonitoring Fashion Accessory

“…Synthesis of graphene oxide was carried out via the modified Hummers' method. 53 GO was thermally exfoliated using microwave treatment in an LG Microwave oven at maximum power (800 W) for 1 min. 54 The GO instantly heats up and explodes with bright illumination.…”

Porous Fe2O3 Nanoparticles as Lithium-Ion Battery Anode Materials

“…In practical applications, it is widely used in water treatment, lithium-ion batteries (LIBs), magnetic recording, gas sensors, and catalysis . Because the pore size and morphology of pores have a greater impact on the physical and chemical properties of Fe 2 O 3 , various forms of α-Fe 2 O 3 have been prepared, such as rods, wires, tubes, pieces, loops, cubic, porous, core–shell, and hollow . The materials of these morphologies can be divided into two categories: one is a solid material without an internal cavity and the other is a hollow material.…”

“…6 Because the pore size and morphology of pores have a greater impact on the physical and chemical properties of Fe 2 O 3 , various forms of α-Fe 2 O 3 have been prepared, such as rods, 7 wires, 8 tubes, 9 pieces, 10 loops, 11 cubic, 12 porous, 13 core−shell, 14 and hollow. 15 The materials of these morphologies can be divided into two categories: one is a solid material without an internal cavity and the other is a hollow material. Compared with solid materials, hollow materials have more application prospects because hollow structures can enhance cycle stability and have a larger chemical reaction interface in some important areas.…”

A High–Performance Flexible Piezoresistive Pressure Sensor Features an Integrated Design of Conductive Fabric Electrode and Polyurethane Sponge

“…[23] Graphene oxide (GO) has a high concentration of hydrogen bonds and carboxyl groups, which contributes to its good dispersion in water. [24] The strategy of PU sponge impregnated in GO dispersion solution and reduced to prepare rGO@PU sponge, has been widely used in the construction for piezoresistive pressure sensor. [25] Yu et al introduced a fractured microstructure rGO@PU sponge pressure sensor with low-cost, high sensitivity, and excellent cycling stability (over 10 000 cycles).…”

“…Graphene oxide (GO) has a high concentration of hydrogen bonds and carboxyl groups, which contributes to its good dispersion in water. [ 24 ] The strategy of PU sponge impregnated in GO dispersion solution and reduced to prepare rGO@PU sponge, has been widely used in the construction for piezoresistive pressure sensor. [ 25 ] Yu et al.…”