Photocatalytic transformation of chlorophenols under homogeneous and heterogeneous conditions using palladium octadodecylthio phthalocyanine

Homogeneous and heterogeneous photosensitized transformations of 4-chlorophenol (4-CP) and pentachlorophenol (PCP) using palladium octadodecylthiophthalocyanine (PdODPc) were investigated. Under heterogeneous conditions, the photosensitizer was supported on functionalized single walled carbon nanotubes (SWCNTs). Homogeneous photosensitization proved to be more effective than the heterogeneous reaction in terms of percentage of transformation achieved. The kinetics of heterogeneous catalysis proved that ads-PdODPc–SWCNT–COOH (where SWCNT has been functionalized with COOH groups) was reusable for 4-CP while its activity degenerated when reused for PCP. Singlet oxygen was confirmed as playing an active role in the reactions.

Graphical abstractHomogenous photosensitization proved more effective than the heterogeneous reaction in terms of percentage of transformation of 4-chlorophenol and pentachlorophenol using palladium phthalocyanine as a photocatalyst.Figure optionsDownload full-size imageDownload high-quality image (145 K)Download as PowerPoint slideHighlights► Palladium phthalocyanine adsorbed onto single walled carbon nanotubes. ► Adsorbed conjugates used for photocatalysis of chlorophenols. ► Homogeneous photocatalysis also studied. ► Homogeneous catalysis more efficient than heterogeneous catalysis.