title: Selective photo-reduction of p-nitrophenol to p-aminophenol by Au deposited CdS nanostructures of different shapes having large surface area.
abstract: The preparation and photocatalytic reductive ability of a new spongy flower or cotton bud like amorphous CdS microstructures (size = 200-300 nm) having intermediate crystal phase between cubic and hexagonal structure and possesses much larger surface area ca. 119 m2 g(-1) is demonstrated here. Structural analysis has been done by TEM, XRD, BET surface area, UV-Vis absorption, luminescence analysis, and photocatalytic study. The photoreactivity of as-prepared CdS for p-nitrophenol reduction to p-aminophenol conversion under visible light (150 W halogen lamp) irradiation has been found to be greatly enhanced from 62% to 94% (yield) and 81% to 100% (selectivity) after 1 wt% Au deposition. The obtained p-aminophenol yield is always better than 32% for CdS nanosphere (size 10-12 nm) and 40% for CdS nanorod (length/width in nm = 126/6). Surface passivation with a thin layer of SiO2 coating over this flower like spongy CdS appreciably increased the BET surface area to 158 m2 g(-1) and displayed stable photocatalytic activity for p-nitrophenol reduction up to 30 h of light exposure as compared to bare CdS of low activity because of its easy photodissolution. A good co-relation between the BET surface area and surface photoactivity of as-prepared CdS with the conventional cubic and hexagonal CdS nanoparticles of different dimensions is established here.
authors.affiliation: School of Chemistry and Biochemistry, Thapar University, Patiala, 147004 Punjab, India.
authors.forename: Nidhi
authors.initials: N
authors.lastname: Gupta
authors.forename: Bonamali
authors.initials: B
authors.lastname: Pal
mesh_terms: D000627:Aminophenols / Q000138:chemical synthesis* / Q000528:radiation effects; D019187:Cadmium Compounds / Q000737:chemistry* / Q000528:radiation effects; D003460:Crystallization / Q000379:methods*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006046:Gold / Q000737:chemistry* / Q000528:radiation effects; D008027:Light; D008422:Materials Testing; D049329:Nanostructures / Q000737:chemistry* / Q000528:radiation effects / Q000648:ultrastructure*; D009596:Nitrophenols / Q000737:chemistry* / Q000528:radiation effects; D010084:Oxidation-Reduction / Q000528:radiation effects; D010316:Particle Size; D018036:Selenium Compounds / Q000737:chemistry* / Q000528:radiation effects
chemical_list: D000627:Aminophenols; D019187:Cadmium Compounds; D009596:Nitrophenols; D018036:Selenium Compounds; D006046:Gold; C058667:cadmium selenide