An comprehensive review on the spray pyrolysis technique: Historical context, operational factors, classifications, and product applications

Nanotechnology is the study and application of materials, structures, devices, and systems that are based on phenomena at the nanoscale, which is about one hundred nanometers or smaller. One method for synthesizing nanomaterials is spray pyrolysis (SP), which involves spraying a precursor solution or suspension into a high-temperature furnace or other heated environment, where it decomposes to form nanoparticles. SP is considered to be a cost-effective method that can be easily transferred from a laboratory setting to industrial manufacturing, and it has the ability to produce a wide range of nanomaterials, including metals, semiconductors, and ceramics, in a single step. There are various types of SP, including tubular reactors, FSP, ECM,PSP, VFSP, and USP. These processes have unique parameters and requirements, with some using a flame as the source of heat and reactants and others using ultrasonic waves to generate the spray. Electrostatic spray deposition (ESD) is a process that uses charged particles to deposit thin films or coatings on a substrate. Emulsion, a mixture of two immiscible liquids stabilized by an emulsifying agent, can also be used in SP. SP has the potential to be used in various applications, such as nanomedicine, sensing, electrochemical devices, catalysis, and energy conversion and storage. However, further research is needed to fully understand the potential of this unique synthesis mechanism and to develop new applications for SP-produced nanomaterials. •Spray pyrolysis is a utilized technique for depositing thin films of metals, semiconductors, and oxides.•SP is one of the promising methods used to produce particles with controlled characteristics including size, morphology, and composition.•To obtain nanoparticles in spray pyrolysis, it is crucial to control salt's solubility, solvent evaporation rate, and precipitate diffusion.