Natural wolframite as a novel visible-light photocatalyst towards organics degradation and bacterial inactivation

Publication date: Available online 6 December 2019Source: Catalysis TodayAuthor(s): Linghui Li, Yan Li, Yanzhang Li, Anhuai Lu, Hongrui Ding, Po Keung Wong, Hongli Sun, Junxian ShiAbstractTungstate oxide is a new kind of anionic semiconductor material, which has been received much attention due to its good photocatalytic performance and long-term stability. To facilitate large-scale application, the natural counterpart of tungstate oxide, wolframite, was firstly used as a visible-light mineral photocatalyst in this study. Its mineralogical and photocatalytic properties were characterized and compared with two synthetic end-member minerals, FeWO4 and MnWO4. The results showed natural wolframite in the form of (Fe,Mn)WO4, had a bandgap of only 1.5 eV, far lower than that of FeWO4 (2.3 eV) and MnWO4 (2.6 eV). Under visible-light, natural wolframite exhibited remarkable photoactivity towards degradation of methylene blue (MB, 5 mg/L) and disinfection of Escherichia coli K-12 (107 cfu mL−1) under neutral pH. The MB degradation rate in the presence of both wolframite and H2O2 was as 3-fold or 14-fold as that in the controls without light or H2O2, respectively. And the disinfection rate using wolframite was at least 5 times higher than that using MnWO4 or FeWO4. Hydroxyl radical (OH•), as detected by electron paramagnetic resonance, was demonstrated as the major reactive oxygen species by using different scavengers in the photocatalytic reactions. The production of OH•...
Source: Catalysis Today - Category: Chemistry Source Type: research