Facile synthesis of IrO 2 nanoclusters and their application as catalysts in the degradation of azo dyes

Authors : Rajni LASYAL, Anjali GOEL

Pages : 941-957

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Publication Date : 0000-00-00

Article Type : Research Paper

Abstract :  A robust synthesis of iridium oxide insert ignore into journalissuearticles values(IrO 2 ); ` role=`presentation`> 2 ); 2 ); _{2}); nanoclusters using methanol as a reducing agent via the chemical reduction method is reported in this article. Polyvinylpyrrolidone insert ignore into journalissuearticles values(PVP); and polyoxyethyleneinsert ignore into journalissuearticles values(23); lauryl ether insert ignore into journalissuearticles values(POLE); were used as stabilizers. The formation of IrO 2 ` role=`presentation`> 2 2 _{2} nanoclusters was confirmed by the appearance of new absorption peak at 230 nm in UV-vis spectra. XRD and TEM were used to determine the degree of crystallinity and size of nanoclusters, respectively. Further characterization studies were carried out by FT-IR spectroscopy to investigate the coordination between IrO 2 ` role=`presentation`> 2 2 _{2} nanoclusters and stabilizers. The size of the nanoclusters was found to be a factor of the ratio of solvent to reductant and precursor to stabilizer. It was found that PVP-stabilized IrO 2 ` role=`presentation`> 2 2 _{2} nanoclusters are smaller in size with narrow distribution in contrast to POLE-stabilized IrO 2 ` role=`presentation`> 2 2 _{2} nanoclusters. The catalytic activity of these nanoclusters was examined in the degradation of some azo dyes, acid orange 10 insert ignore into journalissuearticles values(AO 10);, acid red 14 insert ignore into journalissuearticles values(AR 14);, and acid red 26 insert ignore into journalissuearticles values(AR 26);, in aqueous medium. PVP-stabilized IrO 2 ` role=`presentation`> 2 2 _{2} nanoclusters are catalytically more efficient than POLE-stabilized IrO 2 ` role=`presentation`> 2 2 _{2} nanoclusters, which was supported by the calculation of turnover frequencies. Thus, IrO 2 ` role=`presentation`> 2 2 _{2} nanoclusters are expected to play an imperative role in the field of catalysis and environmental remediation.
Keywords : IrO 2 nanoclusters, polyvinylpyrrolidone, polyoxyethylene 23, lauryl ether, turnover frequency, environ mental remediation