Synthesis and photophysics of 6‐dimethylaminopurine‐capped Q‐CdS nanoparticles—a study of its photocatalytic behavior

Abstract

Nanoparticles of CdS have been stabilized in aqueous medium by surface capping with 6- dimethylaminopurine at pH 11.0 in the presence of excessCd2+. The nucleation of the cluster is controlled through coordination of 6-dimethylaminopurinevia. -N(CH3)2group. 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 about9×109dm3mol−1s−1. Irradiation of the reaction mixture containing CdS and indole by light ofλ>360nm results in the formation of indigo with a quantum efficiency of 0.1.

Effects of Composition and Calcination Temperature on Photocatalytic Evolution over from Glycerol and Water Mixture

“…Nevertheless, the recombination of the photogenerated electrons and holes is still a considerable drawback. In order to improve the photoactivity of CdS, vast efforts have been devoted to the study of CdS preparation or modification, and fruitful achievements have been got, such as the formation of the size-quantized CdS nanocrystals [6,18], loading noble metals [7,19], and coupling CdS with other semiconductors [12,20]. Even some of the composite semiconductors form solid solutions instead of being simply coupled [20].…”

Biotemplated Inorganic Nanostructures: Supramolecular Directed Nanosystems of Semiconductor(s)/Metal(s) Mediated by Nucleic Acids and Their Properties

“…These particles were relatively much smaller (average diameter 2 nm) having a narrow size distribution. For these particles the fluorescence band is now moved to still higher energy at 2.36 eV (525 nm), and the Φ fl for these particles is now improved to about 0.03 . The appearance of a sharp excitonic peak in the optical absorption and band gap emission with a high quantum yield clearly indicate 6-DMAP to be acting as a better capping agent compared to purine and adenine.…”

“…Purines being the important constituents of nucleotides, Kumar and Mital synthesized cadmium sulfide capped with purine, adenine, 6-(dimethylamino)­purine (6-DMAP), and guanine. In these investigations chelation of Cd 2+ with the nucleic bases was observed to restrict the CdS nucleation and control the nanostructure size in a dynamic process.…”

The extraction of gold nanoparticles from oat and wheat biomasses using sodium citrate and cetyltrimethylammonium bromide, studied by x-ray absorption spectroscopy, high-resolution transmission electron microscopy, and UV–visible spectroscopy

“…Currently, amines with long alkane chains, aromatic amines, and other surfactants have been utilized in the preparation of metal nanoparticles [14][15][16][17]. These compounds are used for different purposes, including controlling the growth and extraction/dispersion of gold nanoparticles into different liquid phases.…”