Synthesis and photophysics of 6-dimethylaminopurine-capped Q-CdS nanoparticles—a study of its photocatalytic behavior. (2004)

• Record Type: Journal Article
• Authors: Kumar, Anil; Mital, Shipra
• Is Part Of: International journal of photoenergy. Volume 6:Number 2(2004)
• Page Start: 61
• Page End: 68
• Publication Date: 2004
• Subjects: Photochemistry -- Periodicals; Photobiology -- Periodicals; Chemistry, Physical and theoretical -- Periodicals; Photochimie; Photobiologie; Chimie physique et théorique; Chemistry, Physical and theoretical; Photobiology; Photochemistry; Electronic journals; Periodicals; 541.35
• DOI: 10.1155/S1110662X04000091
• Languages: English
• ISSNs: 1110-662X

Abstract

Abstract : Nanoparticles of CdS have been stabilized in aqueous medium by surface capping with 6- dimethylaminopurine at pH 11.0 in the presence of excessCd 2+ . The nucleation of the cluster is controlled through coordination of 6-dimethylaminopurine via . -N ( CH 3 ) 2 group. Excess 6-dimethylaminopurine binds to the core structure through H-bonding involving protonated N(9). CdS capped with 6-dimethylaminopurine produced relatively small sized particles (2 nm) having a narrow size distribution. These particles did not exhibit any Ostwald's ripening and its solid sample could be fully redispersed in aqueous medium. Thermolysis results in the growth of these particles but demonstrates a better photocatalytic activity. Relaxation kinetics reveals the surface to contain a large number of surface states and the emission is originated by the presence of sulfur vacancies on the particle. The addition of indole simply quenches the emission of CdS in a bimolecular collisional process at a diffusion-controlled rate of about9 × 10 9 dm 3 mol − 1 s − 1 . Irradiation of the reaction mixture containing CdS and indole by light ofλ > 360 nm results in the formation of indigo with a quantum efficiency of 0.1.