Photodegradation of orange G by the hetero-junction x%Bi2S3/TiO2 under solar light. (1st December 2016)

• Record Type: Journal Article
• Authors: Boumaza, S.; Bellal, B.; Boudjemaa, A.; Trari, M.
• Is Part Of: Solar energy. Volume 139(2016)
• Page Start: 444
• Page End: 451
• Publication Date: 2016-12-01
• Subjects: Bi2S3/TiO2 -- Hetero-junction -- Orange G -- Photo-degradation -- Solar light; Solar energy -- Periodicals; Solar engines -- Periodicals; 621.47
• DOI: 10.1016/j.solener.2016.10.009
• Languages: English
• ISSNs: 0038-092X

Abstract

Highlights: The work deals with the photoelectrochemistry of the new hetero-junction Bi2 S3 /TiO2 . The hetero-junction Bi2 S3 /TiO2 is elaborated by precipitation. The enhanced photoactivity is due to the effective dispersion of Bi2 S3 . The OG oxidation follows a pseudo first-order kinetic model. The photoactivity is enhanced under solar irradiation because of TiO2 activation. Abstract: The preparation and characterization of the hetero-junctions x%Bi2 S3 /TiO2 (x = 1, 5, 10 and 15%) and their photocatalytic performances for the degradation of orange G (OG) under visible light irradiation are reported. The hetero-junctions are synthesized by precipitation method from bismuth nitrate on TiO2 . The forbidden bands of Bi2 S3 and TiO2 are found to be 1.54 and 3.43 eV respectively. Bi2 S3 acts as sensitizer and exhibits n -type conductivity evidenced from the anodic photocurrent and capacitance measurements. The degradation of OG is confirmed by spectrophotometry and chemical oxygen demand (COD). The photocatalytic efficiency of the hetero-junction is dependent on the proportion of Bi2 S3 . Under visible light, a fast degradation is obtained on 10% Bi2 S3 /TiO2 and the OG degradation (10 mg L − 1 ) follows a first order kinetic with a rate constant of 0.32 h −1 . The performance of the prepared hetero-junction is better than that of the direct mixture of compounds due to intimate contact Bi2 S3 /TiO2 . Under solar light, the photoactivity is strongly enhanced with a rate constant of 3.42 h −1 .