Sustainable synthesis of indium oxide nanoparticles via Aloe Vera for gas sensing applications

A green synthesis approach was used to produce nanocrystalline indium oxide (In₂O₃) nanoparticles from the Aloe Vera Barbadensis Miller species. The obtained In₂O₃ powder was subsequently employed as a functional material to build thick film resistors (TFR) as a sensor on a porous alumina substrate using screen printing method. The TFR samples were sintered at three different temperatures: 600, 700, and 800 °C. A variety of analytical techniques was used to characterize the nanocrystalline In₂O₃ powder, including Fourier Transform Infrared (FTIR), Ultraviolet–Visible–Near Infrared (UV–Vis–NIR) spectroscopy, Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS), and X-Ray Diffraction (XRD). Additionally, electrical properties and sensor performance were evaluated. The results showed that the electrical resistivity of the thick film sensor created using the green synthesis method was much higher than that of traditional synthesis techniques. The green synthesis of nanocrystalline In₂O₃ with Aloe Vera not only benefits the environment, but it also improves the material's sensitivity and function as an ethanol sensor. This investigation demonstrates the promise of green synthesis techniques for creating high-performance sensing materials and devices.