This review article emphases on the modern approaches to the types of sol-gel materials that are beneficial for electrochemistry, monitored by a report of recent advances in the numerous fields of sol-gel electrochemistry. Modified electrodes for sensors and supercapacitors as well as anti-corrosion are described. Sol-gel synthesis expands the capabilities of technologists to obtain highly porous, homogeneous, and hybrid thin-film materials for supercapacitor electrode application. The widespread materials are transition metal oxides, but due to their low conductivity, they greatly impede the rate capability of electrochemical supercapacitors. The way to optimize their properties is the production of complex oxides or different composites. Among the new materials, a special place is occupied by perovskites and materials with an olivine-type structure, which can be easily obtained by the sol-gel method. The sol-gel coating process has demonstrated excellent chemical stability to advance the corrosion resistance of the various metal alloy substrates. Furthermore, the sol-gel process is a user-friendly technique for applying a hybrid sol-gel coating to provide corrosion resistance. The hybrid sol-gel coating technique is the most attractive, easy to prepare at a lower temperature, and has shown the potential to swap Cr-based coatings. The hybrid sol-gel coating has exhibited promising properties of adherent and uses chemically inert to enhance the corrosion resistance of the metal and alloys. Hence, this review article emphases on the recent advances and approaches in the sol-gel coating processes that influence the belongings of its hybrid sol-gel coating for protecting metal substrates and their alloys from corrosion. In addition, the author discusses the current problem and challenges of hybrid anti-corrosion sol-gel coatings. Metal oxides and composites based on them are actively used to create electrochemical sensors. They synthesized, including the anhydrous and citrate sol-gel methods. Such materials are widely used as glucose biosensors and harmful gas sensors.
The SiO2ZrO2 composite films were prepared by means of sol-gel technology and characterized by scanning electron microscopy, energy dispersive X-ray (EDX) analysis, and X-ray diffraction. The presence of the stable monoclinic ZrO2 with an impurity of tetragonal phases is shown. The film surface is characterized by the presence of ZrOCl2·6H2O or ZrCl(OH)/ZrCl(OH)2 grains. The crystallite size negligibly depends on the annealing temperature of the film and amount to 10–12 nm and 9–12 nm for the films thermally treated at 200 °C and 500 °C, respectively. The film’s resistance is rather sensitive to the presence of NO2 impurities in the air at a low operating temperature (25 °C). Accelerated stability tests of the initial resistance showed high stability and reproducibility of the sensor based on the SiO2ZrO2 film thermally treated at 500 °C.
Silicon-carbon films have been deposited on silicon and Al2O3/Cr-Cu substrates, making use of the electrolysis of methanol/dimethylformamide-hexamethyldisilazane (HMDS) solutions. The electrodeposited films were characterized by Raman spectroscopy and scanning electron microscopy, respectively. Moreover, the nucleation and growth mechanism of the films were studied from the experimental current transients.