S-scheme heterojunction g-C3N4/TiO2 with enhanced photocatalytic activity for degradation of a binary mixture of cationic dyes using solar parabolic trough reactor

• Published in: Chemical engineering research & design 2021-10, Vol.174, p.307-318
• Main Authors: Barzegar, Mohammad Hossein, Sabzehmeidani, Mohammad Mehdi, Ghaedi, Mehrorang, Avargani, Vahid Madadi, Moradi, Zohreh, Roy, Vellaisamy A.L., Heidari, Hadi
• Format: Article
• Language: English
• Subjects: Binary mixtures; Carbon nitride; Catalytic activity; Cationic dyes; Chemical synthesis; Continuous flow; Continuous flow loop photoreactor; g-C3N4/TiO2; Heterojunctions; Mathematical analysis; Methylene blue; Mixture dyes; Nanoparticles; Photocatalysis; Photodegradation; Pollutants; Rhodamine; Simultaneous degradation; Solar collectors; Solar energy; Solar parabolic trough; Titanium; Titanium dioxide
• ISSN: 0263-8762; 1744-3563
• DOI: 10.1016/j.cherd.2021.08.015

[Display omitted] •Preparation of g-C3N4/TiO2 as a S-scheme system in order to degrade MB and RhB dyes from aqueous solution.•Design and Fabrication of parabolic trough collectors as a continuous flow-loop photoreactor for photo-degradation.•Natural solar light irradiation and blue LED light irradiation are compared for the photocatalytic process.•Examine the effects of different operational parameters such as the amount of photocatalyst, dyes concentration and time. Developing photocatalytic systems by larger design to achieve degradation of dye pollutants by using solar light is highly desirable. Present work is devoted to the synthesis of step-scheme (S-scheme) g-C3N4/TiO2 heterojunction which subsequently employed for simultaneous degradation of a binary mixture of Methylene blue (MB) and Rhodamine B (RhB) solution in parabolic trough collectors (PTC) as continuous flow loop photoreactor. The as-prepared g-C3N4/TiO2 was analyzed by various techniques such as FE-SEM, EDS, XRD, FT-IR, BET, elements mapping and DRS. The composite central design (CCD) was applied to express mathematical relationships among variables such as process time, catalyst mass and initial concentrations of MB and RhB in the degradation process. The photocatalytic activity of the as-prepared composite is higher than pure TiO2 and g-C3N4 that is attributed to the positive synergetic effect of S-scheme between g-C3N4 and TiO2 nanostructure. Under solar irradiation in PTC, g-C3N4/TiO2 was able to degrade about 94.92 and 93.07% of binary mixture MB and RhB, respectively.