Improved photocatalytic activity of CdSe-nanocomposites: effect of Montmorillonite support towards efficient removal of Indigo Carmine.
To ascertain the contribution of adsorptive capacity of Montmorillonite (MMT) towards photocatalytic process, CdSe-MMT nanocomposites are explored for adsorptive removal of Indigo Carmine (IC). The nanocomposites are prepared via two approaches: (a) in-situ formation and (b) wet impregnation of CdSe onto MMT support. XRD analysis of composites suggested the proper dispersion of CdSe nanoparticles in MMT clay matrix with spherical morphology of 5-10nm sized CdSe nanoparticles. These nanocomposites are employed for photocatalytic degradation of IC under visible light at various IC concentrations and different amount of catalyst. Kinetics of IC is found to be of pseudo-second order with 10% in-situ and 50% loaded nanocomposites exhibiting better photocatalytic activity at 1.0 g L(-)(1) catalyst and 100 mg L(-)(1)of IC. Dynamics of its adsorptive removal on the composite surface evaluated by employing error estimation tools clearly suggest that Redlich-Peterson and Flory-Huggins adsorption isotherms effectively describe the multi-layer process. It is observed that spontaneous, exothermic chemisorption process occurring on the surface indeed enhances photocatalytic activity. Moreover, such a feature is also found to be associated with diffusion of IC within mesoporous structure of MMT that subsequently favors pore-diffusion controlled adsorption process. IR spectral analysis demonstrated that IC molecule is degraded on the catalyst surface. Light or oxygenated species induced photocorrosion of CdSe is suppressed due to its composite formation with MMT that results in 620 ppm removal of IC during successive cycles; a feature ascribed as improved photocatalytic activity for CdSe nanoparticles.
Nanoscience Group, Department of Chemistry, Post-graduate and Research Centre, MES Abasaheb Garware College, Karve Road, Pune 411004, India. Electronic address: rajuchikate29@gmail.com.
Rajeev C
RC
Chikate
Nanoscience Group, Department of Chemistry, Post-graduate and Research Centre, MES Abasaheb Garware College, Karve Road, Pune 411004, India. Electronic address: brijesh_kadu@yahoo.co.in.
Brijesh S
BS
Kadu
D000327:Adsorption; D001546:Bentonite / Q000737:chemistry*; D019187:Cadmium Compounds / Q000737:chemistry*; D002384:Catalysis / Q000528:radiation effects; D004058:Diffusion; D006863:Hydrogen-Ion Concentration; D007203:Indigo Carmine / Q000302:isolation & purification*; D007700:Kinetics; D008027:Light; D008958:Models, Molecular; D053761:Nanocomposites / Q000737:chemistry* / Q000648:ultrastructure; D017711:Nonlinear Dynamics; D059027:Recycling; D018036:Selenium Compounds / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013696:Temperature; D013997:Time Factors; D014961:X-Ray Diffraction
D019187:Cadmium Compounds; D018036:Selenium Compounds; D001546:Bentonite; C058667:cadmium selenide; D007203:Indigo Carmine
Adsorption isotherms; CdSe nanocomposites; Indigo Carmine; Intra-particle diffusion; Photocatalysis