A highly efficient immobilized ZnO/Zn photoanode for degradation of azo dye Reactive Green 19 in a photocatalytic fuel cell

• Published in: Chemosphere (Oxford) 2017-01, Vol.166, p.118-125
• Main Authors: Lee, Sin-Li, Ho, Li-Ngee, Ong, Soon-An, Wong, Yee-Shian, Voon, Chun-Hong, Khalik, Wan Fadhilah, Yusoff, Nik Athirah, Nordin, Noradiba
• Format: Article
• Language: English
• Subjects: Azo Compounds - chemistry; Azo Compounds - isolation & purification; Azo dye Reactive Green 19; Coloring Agents - chemistry; Coloring Agents - isolation & purification; Conductivity; Degradation; Electric Power Supplies; Electricity generation; Electrodes; Immobilized ZnO/Zn; Photocatalytic fuel cell; Photochemical Processes; Waste Water - chemistry; Water Purification - instrumentation; Water Purification - methods; Zinc - chemistry; Zinc Oxide - chemistry
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2016.09.082

Photocatalytic fuel cell (PFC) is a potential wastewater treatment technology that can generate electricity from the conversion of chemical energy of organic pollutants. An immobilized ZnO/Zn fabricated by sonication and heat attachment method was applied as the photoanode and Pt/C plate was used as the cathode of the PFC in this study. Factors that affect the decolorization efficiency and electricity generation of the PFC such as different initial dye concentrations and pH were investigated. Results revealed that the degradation of Reactive Green 19 (RG19) was enhanced in a closed circuit PFC compared with that of a opened circuit PFC. Almost 100% decolorization could be achieved in 8 h when 250 mL of 30 mg L−1 of RG19 was treated in a PFC without any supporting electrolyte. The highest short circuit current of 0.0427 mA cm−2 and maximum power density of 0.0102 mW cm−2 was obtained by PFC using 30 mg L−1 of RG19. The correlation between dye degradation, conductivity and voltage output were also investigated and discussed. [Display omitted] •A sustainable photocatalytic fuel cell in the absence of supporting electrolyte.•An efficient immobilized ZnO/Zn photoanode was fabricated.•Close circuit gave higher degradation than opened circuit photocatalytic fuel cell.•Conductivity of the dye solution increased with increase of intermediate products.