Bio-assisted synthesized Pd nanoparticles supported on ionic liquid decorated magnetic halloysite: an efficient catalyst for degradation of dyes

Abstract

Using natural materials, i.e. halloysite nanoclay that is a biocompatible naturally occurring clay and Heracleum persicum extract that can serve as a green reducing agent, a novel magnetic catalyst, fe 3 o 4 / Hal-Mel-TEA(IL)-Pd, has been designed and fabricated. To prepare the catalyst, halloysite was first magnetized (magnetic particles with mean diameter of 13.06 ± 3.1 nm) and then surface functionalized with melamine, 1,4 dibromobutane and triethanolamine to provide ionic liquid on the halloysite surface (5 wt%). The latter was then used as a support to immobilize Pd nanoparticles that were reduced by Heracleum persicum extract. The characterization of the catalyst established that the loading of Pd in fe 3 o 4 /Hal-Mel-TEA(IL)-Pd was very low (0.93 wt%) and its specific surface area was 63 m 2 g −1 . Moreover, the catalyst showed magnetic property (Ms = 19.75 emu g −1 ) and could be magnetically separated from the reaction. The catalytic performance of the magnetic catalyst for reductive degradation of methyl orange and rhodamine B in the presence of NaBH 4 in aqueous media was investigated. The activation energy, enthalpy, and entropy for the reduction of methyl orange were estimated as 42.02 kJ mol −1 , 39.40 kJ mol −1 , and −139.06 J mol −1 K −1 , respectively. These values for rhodamine B were calculated as 39.97 kJ mol −1 , 34.33 kJ mol −1 , and −155.18 Jmol −1 K −1 , respectively. notably, fe 3 o 4 /Hal-Mel-TEA(IL)-Pd could be reused for eight reaction runs with negligible loss of the catalytic activity (~3%) and Pd leaching (0.01 wt% of the initial loading).Application of low-cost, biocompatible and available natural compounds for the catalytic purposes has attracted tremendous attention. In this regard, use of halloysite (Hal) that is a dioctahedral 1:1 clay of the kaolin group has received growing interest 1-3 . Apart from high thermal, chemical and mechanical stability, the cylindrical morphology and opposite chemical and electrical properties of inner and outer surfaces of Hal, make it distinguished from other clays and broaden its utility for many applications such as cleaning 4 , adsorbents 5,6 , energy storage, catalysis, flame retardancy 1 , sustainable release of drugs etc. Regarding catalysis, Hal not only can be utilized as a catalyst, but also can be applied as a support for the development of reusable catalysts. To date, various chemical, photochemical and electrochemical transformations such as coupling reactions 7,8 , hydrogenation 9,10 , oxidation have been promoted by using Hal-based catalysts [11][12][13][14][15] . Organic dyes such as methylene blue, rhodamine B (RhB) and methyl orange (MO) are toxic chemicals with potential health threat 16 . The release of these compounds in the industrial waste water has raised many concerns and motivated many studies for the efficient removal of these hazardous pollutants or their conversion into less toxic compounds 17,18 . In this context, several approaches, such as use of adsorbents, photodegradation, electrochemical degradations, membrane p...

Pd on magnetic hybrid of halloysite and POSS‐containing copolymer: An efficient catalyst for dye reduction

“…Hal magnetization was performed using the reported method. [ 38 ] Typically, Hal (2.5 g) and dissolved iron salts (FeCl 3 .6H 2 O [1.37 g] and FeCl 2 .4H 2 O [0.5 g]) in water were thoroughly mixed for 2 h at room temperature. Then, the reaction temperature was elevated to 60°C, and 10 mL of aqueous ammonia was added to form the precipitate.…”

“…Catalytic dye degradation was performed according to classic procedure [ 38 ] in which MO or RhB was used as organic dyes and MNPs/Hal‐POSS‐HEMA‐Pd as well as NaBH 4 was applied as catalyst and reducing agent respectively. In short, NaBH 4 (0.3 mL, 0.1 M) and the optimum content of the catalyst (see Section 3) and dye (3 mL) were mixed and agitated at different temperatures (see Section 3).…”

Gold nanoparticles decorated biguanidine modified mesoporous silica KIT-5 as recoverable heterogeneous catalyst for the reductive degradation of environmental contaminants

“…The procedure successfully transforms the organic pollutants to safer chemicals being tender to natural waters. There have been several reports published in recent years involving different kind of nanomaterials to catalyze the reduction of organic dyes [21][22][23][24][25][26][27][28][29] . Being a part of this study, towards the continuous development of this protocol 27 , we wish to report gold nanoparticle embedded biguanidine functionalized and amine modified mesoporous KIT-5 as a novel nanocomposite catalyst in the reduction of some specific organic dyes, namely, Methylene Blue (MB), Methyl Orange (MO) and Rhodamine B (RhB) using NaBH 4 as reducing agent (Scheme 1).…”

In situ decoration of Au NPs over polydopamine encapsulated GO/Fe3O4 nanoparticles as a recyclable nanocatalyst for the reduction of nitroarenes

“…In continuation to our current research on the precise designing and sustainable development of novel heterogeneous nano materials as effective catalysts 15 , 18 , 20 , 21 , 52 – 69 , we thought, it is worthwhile to construct a noble metal adorned magnetically isolable high surface area nanocomposite and examine its catalytic activity. We are specifically interested in nanocatalyzed organic transformations being conducted under green conditions in order to keep the environment safe and clean.…”