International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

In this paper, a two-dimensional (2D) material graphene with exceptional electronic and mechanical properties is discussed as a promising candidate for chemiresistive sensor applications. High surface area and superior charge carrier mobility of graphene enable rapid and sensitive detection of gaseous analytes, making it an attractive alternative to conventional metal oxide semiconductor (MOS) sensors. The review of recent advancements in graphene-based chemiresistive gas sensors is done, highlighting their operational principles, fabrication techniques, and performance enhancements through material modifications such as reduced graphene oxide (rGO). Additionally, we examine the application of graphene sensors in environmental monitoring, where their ability to detect pollutants like NO₂ , NH₃ , and CO₂ with high sensitivity and low power consumption provides a significant advantage over traditional sensing technologies. Despite these advancements, challenges such as selectivity, standardization, and sensor stability remain critical areas for future research.

Nowadays, the decrease of CO2 concentration in the atmosphere and/or its utilization need urgent resolution. At the same time, preparation of advanced graphene-based composites through effective environmentally benign procedures remains in the focus of intensive research. In the present work, composites consisted of reduced graphene oxide and nanocarbons (rGO/nC) were prepared by simultaneous reduction reaction of solid graphite oxide and CO2 gas over alkaline earth reductant. The structure and the morphology of the prepared composite material were examined employing X-ray diffraction analysis and scanning electron microscopy. It was revealed that the characteristic narrow peak of the graphite oxide (GtO) at low 2θ (~11o) was not present in the pattern of the composite suggesting its successful reduction. Instead, a broad one positioned at 26o was recorded which was attributed to the formed nanocarbons. The observed accordion-like morphologies typical for reduced-graphene-oxide type of graphene evidenced the detachment of the graphene layers during the thermal treatment, while the formed nanocarbons were with irregular shape. The rGO/nC composite exhibited specific surface area (485 m2/g) higher than the pure nanocarbons (417 m2/g) obtained without addition of GtO. The outcome was attributed to the influence of the layered rGO which hinders the aggregation of the nanocarbons and facilitates their homogeneous distribution. The prepared composite can be considered as candidates for gas and energy storage applications, while the suggested environmentally benign preparation method can be scaled up to industrial extent due to simplicity.

In this study, graphene oxide (GO) was synthesized from graphite by using the Hummer method. GO was reduced using hydrazine hydrate to achieve reduced graphene oxide (RGO). GO and RGO powders synthesized by these methods can be used as fillers in the production of polymer matrix composite. These synthesized powders was examined in detail using the Zeta Potential (ZP) measurements, Ultraviolet Visible Spectrophotometer (UV-VIS), X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM) equipped with Energy Dispersive Spectroscopy (EDS) analyzer and Thermogravimetric-Differential Thermal Analysis (TG-DTA). All analysis results confirmed the GO and RGO considered as fillers in the production of polymer matrix composite can be prepared successfully.