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Abstract Humidity sensing has been offering a noticeable contribution in different industrial, medical, and agricultural activities. Here, graphene quantum dots doped with polyaniline (PANI) and MnO2 were successfully prepared. The synthesized system is exposed to a set of structural, morphological, and optical investigations. The apparent crystallite size is less than 30 nm, reflecting the nanoscale of the structure, and thus validating the preparation route as evident on XRD pattern. SEM images show a fibrous structure where polyaniline dominates and covers most of the structure’s surface. The evident bands of the FTIR spectrum are designated to the component used in synthesis confirming the chemical structure of the fabricated system. The humidity sensing study of the synthesized structure is carried out through a wide range of relative humidity (RH) levels range of 11–97%. The response and recovery times of the fabricated structure are found to be around 120 and 220s, respectively.

In this work, a novel electrochemical detection strategy was developed based on a metal-organic framework of zinc oxide nanorod nanoparticles and rutin for selective screening of Thiourea as toxic chemicals. The zinc oxide nanorod were synthesized by following direct chemical precipitation methods and characterized by X-ray diffraction and X-ray photoelectron spectroscopy analysis. The surface of modified electrodes was also characterized by field emission scanning electron microscopes, energy-dispersive X-ray spectroscopy, and attenuated total reflectance flourier transform infrared spectroscopy. Furthermore, the electrochemical activity of the developed sensor was tested by cyclic voltammetry, differential pulse voltammetry, and electrochemical impedance spectroscopy. The modified electrode showed outstanding electro-catalytic activity towards the detection of Thiourea in phosphate buffer saline at a high pH level of 12.0. The proposed sensor showed a linear range of linearity in a concentration ranging from 5.0 × 10−6 - 900 × 10−6 molL−1 and a detection limit of 2.0 × 10−6 molL−1. Moreover, the selectivity of the developed electrochemical sensor was investigated for the detection of Thiourea in the presence of organic compounds and a group of anions. Furthermore, the proposed strategy demonstrated an excellent recovery value in the spiked farmland water and fruit juice sample.

A nano-crystalline spinel ferrite (NC-SF) composites were synthesized using the standard ceramic method and were analyzed by several analytical techniques. The XRD characterization validates the production of a cubic spinel arrangement. Furthermore, XRD analysis showed that the bond length and ionic radii enlarge on A-sites and reduce slightly on B-sites with the increase in the content of Mn-Ti. Moreover, XRD analysis revealed that the crystallite size of Cd-Ti-Al-Mn lies in the range of 22.83-24.44nm. Additionally, the porosity of the Cd-Ti-Al-Mn ferrite samples reduces with increasing the content of Mn-Ti. The FT-IR spectra show one high-frequency band and three low-frequency bands in the range of 400-600 cm-1. The grain size was observed by SEM images to be uniformly distributed and lies within the range of ~0.66-1.18μm. The DC resistivity of the ferrite composite became greater with increasing the content of Mn-Ti. Moreover, the composite behaves electrically as semiconductor. The investigated Cd-Ti-Al-Mn ferrite composites exhibited current controlled negative resistance (CCNR) type of electrical switching characteristics at room temperature. The value of the switching electric field was noted to enlarge with the increase in the content of Mn-Ti. Additionally, there was no ageing observed for electrical switching property in the investigated ferrite composites

In this work, the corrosion inhibition of mild steel at ambient conditions by an antibiotic in a solution that contains silver nanoparticles (AgNPs) and graphene oxide (GO) was studied. GO and AGNPs were prepared by one-step simple and ecofriendly method and characterized by different techniques. Different concentrations of the inhibitor were prepared and their inhibition efficiency in acidic media was investigated. The adsorption characteristics of the inhibitor were studied and it was found that the antibiotic (Cefixime) alone and with GO combined with AgNPs inhibit the corrosion of mild steel by being adsorbed on the surface of mild steel by a physical adsorption mechanism. The adsorption of Cefixime and GO with AgNPs on the mild steel surface was found to be spontaneous. Incorporating AgNPs and GO with Cefixime showed an additional inhibition efficiency when compared with using only Cefixime. This indicates the strong inhibition efficiency offered by incorporating the antibiotic with AgNPs and GO.

In this work, the corrosion inhibition of mild steel at ambient conditions by an antibiotic in a solution that contains silver nanoparticles (AgNPs) and graphene oxide (GO) was studied. GO and AGNPs were prepared by one-step simple and ecofriendly method and characterized by different techniques. Different concentrations of the inhibitor were prepared and their inhibition efficiency in acidic media was investigated. The adsorption characteristics of the inhibitor were studied and it was found that the antibiotic (Cefixime) alone and with GO combined with AgNPs inhibit the corrosion of mild steel by being adsorbed on the surface of mild steel by a physical adsorption mechanism. The adsorption of Cefixime and GO with AgNPs on the mild steel surface was found to be spontaneous. Incorporating AgNPs and GO with Cefixime showed an additional inhibition efficiency when compared with using only Cefixime. This indicates the strong inhibition efficiency offered by incorporating the antibiotic with AgNPs and GO.