Highly reduced ecotoxicity of ZnO-based micro/nanostructures on aquatic biota: Influence of architecture, chemical composition, fixation, and photocatalytic efficiency.
Water Res
; 169: 115210, 2020 Feb 01.
Article
em En
| MEDLINE
| ID: mdl-31670084
ABSTRACT
Developing efficient sunlight photocatalysts with enhanced photocorrosion resistance and minimal ecotoxicological effects on aquatic biota is critical to combat water contamination. Here, the role of chemical composition, architecture, and fixation on the ecotoxicological effects on microalgae of different ZnO and ZnO@ZnS based water decontamination photocatalysts was analyzed in depth. In particular, the ecotoxicological effects of films, nanoparticles and biomimetic micro/nano-ferns were carefully assessed by correlating the algae's viability to the Zn(II) release, the photocatalyst-microalgae interaction, and the production of reactive oxygen species (ROS). The results showed a drastic improvement in algal viability for supported ZnO@ZnS core@shell micro/nanoferns, as their ecotoxicity after 96â¯h light exposure was significantly lower (3.7-10.0% viability loss) compared to the ZnO films (18.4-35.5% loss), ZnO micro/nanoferns (28.5-53.5% loss), ZnO nanoparticles (48.3-91.7% loss) or ZnO@ZnS nanoparticles (8.6-19.2% loss) for catalysts concentrations ranging from 25â¯mgâ¯L-1 to 400â¯mgâ¯L-1. In particular, the ZnO@ZnS micro/nanoferns with a concentration of 400â¯mgâ¯L-1 exhibited excellent photocatalytic efficiency to mineralize a multi-pollutant solution (81.4⯱â¯0.3% mineralization efficiency after 210â¯min under UV-filtered visible light irradiation) and minimal photocorrosion (<5% of photocatalyst dissolution after 96â¯h of UV-filtered visible light irradiation). Remarkably, the ZnO@ZnS micro/nanoferns showed lower loss of algal viability (9.8⯱â¯1.1%) after 96â¯h of light exposure, with minimal reduction in microalgal biomass (9.1⯱â¯1.0%), as well as in the quantity of chlorophyll-a (9.5⯱â¯1.0%), carotenoids (8.6⯱â¯0.9%) and phycocyanin (5.6⯱â¯0.6%). Altogether, the optimized ZnO@ZnS core@shell micro/nanoferns represent excellent ecofriendly photocatalysts for water remediation in complex media, as they combine enhanced sunlight remediation efficiency, minimal adverse effects on biological microorganisms, high reusability and easy recyclability.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Poluentes Químicos da Água
/
Óxido de Zinco
/
Nanoestruturas
Idioma:
En
Ano de publicação:
2020
Tipo de documento:
Article