In situ confined growth of g-C3N4/pigment compound catalyst in porous diatomite for enhancing photocatalytic nicotine elimination and bacterial inactivation

Abstract

Humans spend at least 70% of their time indoors, but indoor air pollution has received very little attention compared to outdoor pollution. Indoor air pollutants include inhalable particulate matter, volatile organic pollutants, and biological pollutants. In particular, nicotine in second-hand smoke and pathogenic microorganisms in the air are the most overlooked pollutants, which pose serious threats to human health. Here, low-cost inorganic pigments and diatomite have been selected to modify g-C3N4 to obtain five novel g-C3N4-based photocatalysts, which are intensely colored and show excellent nicotine degradation performance under both simulated sunlight and white LED illumination. Five g-C3N4-based photocatalytic textiles obtained by supporting the colored photocatalysts on low-melting-point skin–core composite polyester (LMPET) still exhibited outstanding photocatalytic degradation performance and cyclability in removing nicotine. Some of the photocatalytic textiles also displayed highly efficient bacterial inactivation towards E. coli and S. aureus under white LED illumination. Mechanistic research has revealed that the combination of inorganic pigments and diatomite effectively promotes the separation of photogenerated electrons and holes. Moreover, •O2-, 1O2, and •OH have been identified as the main active species in the colored photocatalyst systems. Notably, the colored photocatalysts may be used as dyes to make wall coverings, sofa covers, and so on, which could conceivably purify indoor air while playing a decorative role.