Electrical, Photocatalytic, and Humidity Sensing Applications of Mixed Metal Oxide Nanocomposites

Abstract

Mixed metal oxide nanocomposites (NCs) comprising Cu–Sr (CS), Sr–Cd (SC), and Cd–Cu (CC) were fabricated via a sol–gel method. Structural investigations of fabricated samples were carried out via X-ray diffraction (XRD), scanning electron microscopy (SEM), diffuse reflectance spectroscopy (DRS), and X-ray photoelectron spectroscopy (XPS). The Maxwell–Wagner model, attributing to poor conducting layers around the conducting grains, was indicated to be followed by all of the NCs while investigating the dielectric properties. The Space-charge polarization and hoping mechanism contributed to low AC conductivity at lower frequencies and high AC conductivity at higher frequencies. The as-synthesized NCs effectively degraded two toxic water contaminants, such as crystal violet (CV) and Congo red (CR). Furthermore, the NCs were also evaluated for humidity sensing measurements. All of the NCs indicated efficient response/recovery time with better stability. The extensive investigation suggested the synthesized NCs, well suited for various optical and microelectronic applications.

Electrospun Nickel Manganite (NiMn2O4) Nanocrystalline Fibers for Humidity and Temperature Sensing

“…Precision agriculture requires smart humidity sensors as part of a wireless sensor network [ 4 , 5 ], that includes monitoring of plant soil moisture essential for good plant growth [ 6 , 7 ]. Semiconductor materials, especially metal oxides, are widely applied in gas and humidity sensors [ 8 ] and remain the focus of much research [ 9 , 10 ]. A good sensing material needs to show high sensitivity, good selectivity, and be low-cost, reliable and easy to fabricate [ 8 ].…”

Multifunctional Flexible Humidity Sensor Systems Towards Noncontact Wearable Electronics

“…Similar to metal sulfides, metal oxides-based nanomaterials also exhibit hydrophilic property for sensitive humidity sensors [ 105 ]. Owing to the relatively narrow bandgap nature, metal-oxides nanomaterials with excellent electronic properties are mainly applied for resistive or impedance-type flexible humidity sensors [ 80 , 106 ].…”

Recent advances in cellulose-based membranes for their sensing applications

“…(Blank et al 2016 ; Lv et al 2019a , b ). However, most of the commercially available humidity sensors were based on porous ceramics or metal oxides, which existed some shortcomings, such as the rigid structure, the complicated integration process, the restricted accuracy and sensitivity under high temperature or humidity (Wang et al 2016a , b ; Shaheen et al 2020 ). Therefore, it is vital to develop the humidity sensors with flexibility, wide response range, fast response, high sensitivity and low hysteresis.…”