The continuous growth of industrial activities and increased emission rates negatively affected the air quality. Indoor air pollution, in particular, is a serious problem causing up to 3.2 million premature death yearly [1]. Formaldehyde is one of the major air pollutants occurring in the built environment. Exposure to formaldehyde puts human health in a risk due to its toxicity and carcinogenic effect. This, with the increased public awareness, is driving demand for mitigating indoor formaldehyde. The integrated adsorption-photocatalytic degradation has been viewed as a promising technique for air purification. In this process, the pollutants are captured on the porous adsorbent then, degraded by active photocatalysts (E.g., MnO2) deposited on the adsorbent. Carbonaceous materials, including biochar, are efficient adsorbents for air pollutants owing to their porous structure [2]. They have been successfully used as platform for immobilization of photocatalysts for removal of formaldehyde. For instance, Zhang et al. (2019) synthesized a lignocellulose-based activated carbon fiber paper loaded with MnO2. They observed a decrease in formaldehyde concentration of 59 ppm after 10h. Similarly, Dai et al. (2016) prepared δ-MnO2 deposited on activated carbon fibers. They reported that the formaldehyde removal efficiency reached 97% after 10h. Although prior studies reported high efficiency of carbon material-MnO2 in formaldehyde removal, they investigated high initial pollutant concentration (150 ppm) which is not the case for indoor conditions. Therefore, the investigation of integrated adsorption-photocatalytic degradation performance of biochar-MnO2 at ambient conditions and in the presence of low concentrations of formaldehyde is a topic of interest. Moreover, the utilization of the biochar-MnO2 hybrid for the development of a functional coating for indoor wood seems to be a promising way to potentially enhance the air quality and protect wooden surfaces.
Keywords: Functional, biochar, coating, air purification
Authors
Mariem Zouari
InnoRenew CoE, Slovenia
University of primorska, Slovenia
Miriam Kellock
VTT Technical Research Centre of Finland, Finland
Marc Borrega
VTT Technical Research Centre of Finland, Finland
Matthew Schwarzkopf
InnoRenew CoE, Slovenia
University of primorska, Slovenia
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