Narrow bandgap semiconductor MgIn 2 S 4 has been readily grown onto In 2 O 3 nanofibers by an in situ growing method. The so-formed MgIn 2 S 4 -In 2 O 3 hybrid nanofibers are characterized by strong visible light absorption and intimate MgIn 2 S 4 /In 2 O 3 heterointerfaces. Under visible light illumination ( λ ≥ 400 nm), the hybrid nanofibers demonstrate an exceptionally high photocatalytic activity for Escherichia coli ( E. coli ) disinfection, outcompeting pristine MgIn 2 S 4 , naked In 2 O 3 nanofibers, and many other photocatalytic systems reported. Specifically, the hybrid nanofibers achieve a 7 log reduction in viable cells for merely 20 min illumination while pristine MgIn 2 S 4 and naked In 2 O 3 nanofibers alone are almost inactive. Further analysis indicates that the hybrid nanofibers essentially form a type-II semiconductor heterojunctions which enable spatial separation of photocarriers. Owing to the intimate heterointerfaces, photocarriers can be promptly separated and accumulated respectively in In 2 O 3 and MgIn 2 S 4 thereby allowing continuous generation of copious reactive species for disinfection. This work signifies the usefulness of heterointerfaces in promoting photocarrier separation and provides a useful strategy to upgrade photocatalytic performance from otherwise almost inactive semiconductors.
Li Yunhe,Li Hao,Zhao Baogang,Ma Yanming,Liang Peiyuan,Sun Tianjun
The escalating levels of surface ozone concentration pose detrimental effects on public health and the environment. Catalytic decomposition presents an optimal solution for surface ozone removal. Nevertheless, catalyst still encounters challenges such as poisoning and deactivation in the high humidity environment. The influence of support on catalytic ozone decomposition was examined at a gas hourly space velocity of 300 L·g −1 ·h −1 and 85% relative humidity under ambient temperature using Cu-Mn–doped oxide catalysts synthesized via a straightforward coprecipitation method. Notably, the Cu-Mn/SiO 2 catalyst exhibited remarkable performance on ozone decomposition, achieving 98% ozone conversion and stability for 10 h. Further characterization analysis indicated that the catalyst’s enhanced water resistance and activity could be attributed to factors such as an increased number of active sites, a large surface area, abundant active oxygen species, and a lower Mn oxidation state. The catalytic environment created by mixed oxides can offer a clearer understanding of their synergistic effects on catalytic ozone decomposition, providing significant insights into the development of water-resistant catalysts with superior performance. Graphical