Nanoengineered CdSe quantum dot–montmorillonite composites: an efficient photocatalyst under visible light irradiation

Abstract

Intercalated CdSe–CTAB–MMT nanocomposites with uniform dispersion of CdSe QD's are fabricated by a facile self-assembly approach that significantly enhances visible light induced photocatalytic degradation of Indigo Carmine.

Synergism in semiconducting nanocomposites: visible light photocatalysis towards the formation of C–S and C–N bonds

“…It implies that longitudinal oscillations on the catalyst surface are responsible for negative photon dispersion that ultimately retains the photocatalytic activity even after continuous exposure to light. 41 Thus, it may be argued that the modification of the CdSe/MMT catalyst after continuous exposure to light results in the formation of a robust p-n junction through the passivation of surface structural defects. These features account for the better photostability and excellent photocatalytic efficiency of CdSe/MMT nanocomposites afforded by synergism in CdSe and MMT structures.…”

Orbital Engineering: Photoactivation of an Organofunctionalized Polyoxotungstate

“…Indigo dye has been employed recently as ac onvenientm odel pollutant for similar assays of the oxidation catalysis behaviour of POMs and is particularly useful given its characteristic strong absorption at 613 nm, which can be used as as pectroscopic handle to rapidly assess substrate concentration during photolysis. [15] Initially,c omparative studies between the three clusters were performed, whereby aDMF solution of Indigo dye (20 mm)w as irradiated with aX el amp (390 nm cut-off)i nt he presence of 4 mm POM catalyst( POM/ Indigo 1:5). The results of these experiments are presented in Figure 2b.A sw as expected based on their relative photo-reductionp erformances, {P 2 W 17 }s howed minimal activity in comparisont oa"blank" control( observed pseudo-first-order rate constant( k obs )4 .7 10 À5 s À1 ), whereas {P 2 W 18 }s howedm oderate/slowd ecomposition of the substrate (k obs 1.4 10 À4 s À1 ), and 1 showedb yf ar the best performance (k obs 6.0 10 À4 s À1 ).…”

Chemometrics investigation of the light-free degradation of methyl green and malachite green by starch-coated CdSe quantum dots

“…This is fuelled by size dependent opto-electrical propertiesof quantum dotsin addition to short distance available for charge carriers to reach the surface as size of quantum dots is generally less than minority carrier diffusion length [29,30].Cadmium selenide (CdSe) quantum dots is well-known example for its size tunable band gap that lays in visible region of solar spectrum from 1.74 eV to 3 eV by moving from bulk CdSe to 1.7nm quantum dots [31,32]. As a result, CdSe has potential to become an efficient photocatalyst for oxidation process because of its ability to absorb decent portion of ultraviolet-visible region of solar spectrum along with positive valance band that is suitable to drive oxidation reaction [33][34][35].…”