Synthesis of eosin modified TiO2 film with co-exposed {001} and {101} facets for photocatalytic degradation of para-aminobenzoic acid and solar H2 production.

• Eosin modified TiO 2 film with co-exposed {001} and {101} facets was synthesized. • Sulfite/Eosin-TiO 2 system was used as SO 4 − based Advanced Oxidation Process. • Degradation of PABA was performed by sulfite/Eosin-TiO 2 /solar system. • Under visible light irradiation, Eosin-TiO 2 showed appreciable H 2 production rate. • Solar/Eosin-TiO 2 (/SO 3 2–) is a promising method for environmental sustainability. Owing to the increasing photosensitivity and DNA damage properties of para -aminobenzoic acid (PABA), concerns have been raised over the exposure of humans to PABA. Solar light-driven photocatalysis (SPC) provides a promising solution for the effective removal of organic pollutants especially when directed towards sulfate radical (SO 4 −) production. Herein, we have developed a sulfite-enhanced SPC using Eosin-Y sensitized TiO 2 /Ti film as a photocatalyst. The removal efficiency of PABA was enhanced by coupling Eosin-Y with TiO 2 /Ti film as revealed from 23.6 and 48.9 % PABA degradation by reference-TiO 2 /solar and Eosin-TiO 2 /solar, respectively. The apparent rate constant of PABA degradation by Eosin-TiO 2 was improved by 4.7 times in presence of 5 mM sulfite. Interestingly, Eosin-TiO 2 showed appreciable H 2 production rate under visible light illumination. Solar/sulfite/Eosin-TiO 2 system is a promising technology for environmental sustainability by using the renewable solar energy and air pollutants since sulfite is a waste from flue gas desulfurization process. [ABSTRACT FROM AUTHOR]