Development of phthalocyanine functionalised TiO and ZnO nanofibers for photodegradation of methyl orange

• Published in: New journal of chemistry 2020-10, Vol.44 (38), p.1634-1635
• Main Authors: Mapukata, Sivuyisiwe, Nyokong, Tebello
• Format: Article
• Language: English
• ISSN: 1144-0546; 1369-9261
• DOI: 10.1039/d0nj03326j

The photocatalytic activity of TiO 2 and ZnO based catalysts, which is based on their ability to generate electron-hole pairs upon photoillumination is limited due to their wide band gaps and lack of efficient retrievability post-application. This work reports on the fabrication, characterisation and comparison of electrospun TiO 2 and ZnO nanofibers when bare vs when functionalised with a phthalocyanine. The generated photocatalysts are attractive because they absorb visible light and are easily retrievable and hence reusable. With the Pc anchored onto their surfaces, the anatase TiO 2 nanofibers and the wurzite ZnO nanofibers possessed singlet oxygen quantum yields of 0.22 and 0.16 in water, respectively. Evaluation of the photocatalytic efficiencies of the nanofibers was conducted by studying the photodegradation of methyl orange. The Pc decorated nanofibers were found to be more effective photocatalysts than the bare ones with the phthalocyanine TiO 2 nanofibers being the best. The degradation kinetics were found to follow pseudo first order kinetics and obeyed the Langmuir Hinshelwood model. The nanocatalysts reported herein are therefore feasible candidates for real-life water purification applications. Due to their wide band gaps the use of semiconductor based catalysts for water purification is limited, hence in this work phthalocyanine functionalised TiO 2 and ZnO nanofibers were employed for efficient degradation of organic pollutants.