RESUMEN
Organic pollutants such as dyes and pharmaceutical drugs have become a significant environmental problem due to their unrestricted discharge, especially in water bodies. As a result, an economically viable and environmentally friendly approach to their degradation in water bodies is required and the incorporation of metal tungstate with single metal oxide has attracted attention due to its potential ability towards the photocatalytic degradation of pollutants. The work demonstrates a WO3/g-C3N4/V2O5 nanocomposite synthesized using a facile route wet impregnation method. The results revealed that WO3/g-C3N4/V2O5 nanocomposites are suitable, mainly for their better surface properties, enhanced visible-light absorption, and preferred band positions. Besides that, the degradation of methylene blue (MB) dye is carried out and demonstrated that the complete degradation occurs over 120 min using 10 mg L-1 of WO3/g-C3N4/V2O5 nanocomposite under UV-visible-light irradiation. The scavenger experimental result implies that the photogenerated free electrons and superoxide radials are important role in MB dye degradation. In addition, a possible mechanism is proposed for the photocatalytic activity of WO3/g-C3N4/V2O5 nanocomposite. Moreover, the stability analysis demonstrated that the WO3/g-C3N4/V2O5 nanocomposite can be recycled multiple times.
RESUMEN
Herein, a Bi2S3/Cu2S was successfully synthesized via a simple one-step wet impregnation process. The compositional behavior and electrical and optical properties of photocatalysts were investigated in detail. Photocatalytic technology has shown great promise in wastewater treatment, splitting water to hydrogen, and converting CO2 to fuel. Researchers or scientist are attempting to design sulfate-based heterojunction photocatalytic systems in order to develop novel photocatalysts with excellent performance. Photodegradation of methylene blue (MB) dye and tetracycline (TC) drug under visible light irradiation was used to assess the photocatalytic activity of as-prepared samples. As a result, 2:1% wt of Bi2S3/Cu2S heterostructure composite revealed superior visible light degradation performing of MB dye, and TC drug efficiency as 90.2% and 87.5%, respectively. The prepared hybrid photocatalyst has demonstated a potential for use in the photocatalytic degradation of antibiotic durgs and dyes, indicating a promissing future for its application.
RESUMEN
Catalytic ozonation based on heterogeneous metal oxides is a promising approach to removing ammonia as gaseous nitrogen from water. Herein, MgO/Co3O4/CeO2 was prepared for catalytic ozonation of ammonia in an aqueous solution. The influence of various reaction conditions was systematically investigated and optimized, in which the reaction kinetics was also analyzed. After doping Ce, the catalyst with Mg-Co-Ce molar ratio of 4:1:1 and calcined at 700 °C for 3 h, has abundant surface oxygen vacancies and exhibited excellent performance for the selective catalytic oxidation of ammonia to gaseous nitrogen by ozone. It was found that the catalytic activity of catalysts was positively related to oxygen vacancies concentration on the composites surface, which might play a vital role in selective catalytic ozonation. Under the optimal conditions, the ammonia removal rate in MgO/Co3O4/CeO2 catalytic system was 0.03328 min-1 (R2 = 0.99942), about 2.1 times greater than that of MgO/Co3O4 (0.01597 min-1, R2 = 0.99813), and the selectivity was further enhanced from 73.57% to 86.94%. Moreover, the evolution of nitrogen and chlorine species was determined to discuss the mechanism of selective oxidation of ammonia in the low chlorine-containing solution. This study might promote the understanding of catalytic ozonation of ammonia to gaseous nitrogen selectively.
