Photocatalytic Reduction Efficiency of CO2 Depending on ZnO Particle Size

Abstract

In the face of increasing global carbon dioxide emissions and the urgent need to mitigate climate change, the development of efficient and sustainable strategies for CO2 conversion has gained significant attention. One of the methods of eliminating the harmful effects of CO2 is its photoreduction. In this paper, ZnO was used as an effective photocatalyst for the photoreduction of CO2 in a gas-phase system. The influence of particle size on the process efficiency was investigated. The ZnO materials applied in the studies were characterized using XRD, SEM, and low-temperature nitrogen adsorption (BET) methods. The pore volume distribution was calculated based on the DFT method. The investigation confirmed that it had a significant impact on the formation of the product of photocatalysis carbon dioxide. The main identified product was carbon monoxide. Hydrogen and methane were detected as well. Based on the results, it was found that the process efficiency was enhanced with decreasing ZnO particle size, and the most effective catalyst for the photoreduction of CO2 was the ZnO sample with the smallest particle size (18 nm).