Morphology and photocatalytic properties of Ag2O nanoparticles synthesised in processes based on different forms of energy

In this study, the influence of the energy supply of the system on the properties of the obtained silver oxide nanoparticles (Ag2O NPs) was investigated, including properties that directly affect their photocatalytic properties, i.e. surface area, particle size and nanoparticle stability. The types of supplied energy used in the processes of obtaining nanoparticles, i.e. microwave radiation, infrared radiation, ultraviolet radiation, conventional heating, ultrasound, and mechanical energy were compared by determining their utility power of the appliance, the energy consumption of the appliance, the maximum energy exchange efficiency, and the heating efficiency. Synthesised materials were characterised using different techniques including XRD, STEM, UV-VIS, DLS, FTIR, BET, Raman, zeta potential. The smallest particle sizes were obtained using ultrasound as the energy source, for which the highest material heating gradient (29.89 K/min) was obtained, while the highest heating efficiency (72.37%) was obtained using microwave radiation. The use of microwave and ultrasonic energy ensured a high heating rate of the material while maintaining maximum heating efficiency. The highest photocatalytic activity was exhibited by Ag2O NPs obtained in the microwave reactor obtaining 87% rhodamine removal efficiency in visible light and 52% in UV light.