title: Photodegradation of 4-nitrophenol using cadmium sulphide nanoparticles.
abstract: An efficient method to degrade 4-nitrophenol (4-NP) using cadmium sulphide nanoparticles (CdS NPs) prepared by a novel method as a photocatalyst in the presence of H2O2 as a free radical generator was developed. To investigate the degradation mechanism, the interaction between the substrate (4-NP) and the catalyst (CdS NPs) was studied using UV-visible absorption and emission spectral techniques. Investigation on the effect of pH of the medium on the degradability of 4-NP revealed that neither the acidic (pH 4) nor alkaline (pH 9) is as suitable as pH 6 due to the desorption of 4-NP from the catalyst surface at the former condition and the existence of 4-NP in its most stable quinonoid form at the latter pH. Similarly, the effect of ratio between the photocatalyst (CdS NPs) and the substrate (4-NP) was also investigated to achieve higher efficiency in the photocatalytic reaction.
authors.forename: G
authors.initials: G
authors.lastname: Sangami
authors.forename: R
authors.initials: R
authors.lastname: Nirmala
authors.forename: H Y
authors.initials: HY
authors.lastname: Kim
authors.forename: N
authors.initials: N
authors.lastname: Dharmaraj
mesh_terms: D000042:Absorption; D000818:Animals; D019187:Cadmium Compounds / Q000737:chemistry*; D002384:Catalysis; D004528:Egg Shell; D005609:Free Radicals; D006861:Hydrogen Peroxide / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D053758:Nanoparticles / Q000737:chemistry*; D009596:Nitrophenols / Q000032:analysis*; D009930:Organic Chemicals / Q000032:analysis*; D010777:Photochemistry; D010782:Photolysis; D013056:Spectrophotometry, Ultraviolet; D013440:Sulfides / Q000737:chemistry*; D013997:Time Factors; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D019187:Cadmium Compounds; D005609:Free Radicals; D009596:Nitrophenols; D009930:Organic Chemicals; D013440:Sulfides; D014874:Water Pollutants, Chemical; C034939:cadmium sulfide; D006861:Hydrogen Peroxide; C024836:4-nitrophenol