Chemically synthesized (Ag, Mn2O3)-codecorated ZnO nanoparticles for achieving superior visible light-induced photodegradation and enhanced gas sensing activity

Abstract

Heterostructural engineering and noble metal coupling are effective strategies to optimize semiconductor photocatalytic materials. In this work, (Ag, Mn₂O₃)-codecorated ZnO nanoparticles with different Mn₂O₃ contents (0–10 mol%) were synthesized by integrating the two strategies by a facile two-step polymer network-gel process. The photocatalytic activity of Ag/ZnO (AZM0) was significantly enhanced with the optimum Mn₂O₃ molar ratio of 3 mol%. The degradation efficiency of AZM3 is ∼3 times and ∼4.8 times higher than that of AZM0 for the degradation of methylene blue (MB) upon exposure to simulated sunlight and visible light, respectively. Also, this ternary nanocomposite exhibits enhanced gas sensing performance towards NO₂ under ultraviolet/visible light irradiation at room temperature. The analysis of its microstructural, optical and photoelectrical characteristics suggests the synergistic coupling effects of Ag and Mn₂O₃, in which the significantly enhanced visible light response and hetero-interface charge carrier migration are the critical factors for the improvement of photocatalytic efficiency and gas sensing activity. Furthermore, the effects of recycling ability, the influence of the initial solution pH, the catalyst dosage and the main active species during the catalysis process on photocatalytic activity were explored. This study develops a feasible pathway to consciously construct multiheterostructures for enhancing the photocatalytic activity with great potential applications in toxic pollution abatement and noxious gas detection.