Spontaneous Formation of Ultrasmall Noble Metal Nanoparticles on Cobalt-Based Layered Double Hydroxide for Electrochemical and Environmental Catalysis.

Supported noble metal nanoparticles (NMNPs) are appealing for energy and environment catalysis. To facilitate the loading of NMNPs, in situ reduction of Mn+ on the support with extra reductants/surfactants is adopted, but typically results in aggregated NMNPs with uneven size distributions or blocked active sites of the NMNPs. Herein, the use of cobalt layered double hydroxide (Co-LDH) is proposed as both support and reductant for the preparation of supported NMNPs with ultrasmall sizes and even distributions. The resultant Co-LDH-supported NMNPs exhibit excellent catalytic performance and stability. For example, Ir/Co-LDH displays a low overpotential of 188 mV (10 mA cm-2) for electrocatalytic oxygen evolution reaction and a long-term stability over 100 h (100 mA cm-2) in overall water splitting. Ru/Co-LDH can achieve a 4-nitrophenol reduction with high rate of 0.36 min-1 and S2- detection with low limit of detection (LOD) of 0.34 µm. Overall, this work provides a green and effective strategy to fabricate supported NMNPs with greatly improved catalytic performances.

Nitrophenol Reduction with Silver Oxide Nanostructures as a Sustainable Approach to Environmental Remediation.

We propose silver oxide as a cost-effective and sustainable alternative to noble metals for the catalytic reduction of nitroaromatics. In the present investigation, we adopt a facile and green synthetic route for the synthesis of silver oxide nanostructures. The prepared nanostructures were found to crystallize in the cuprite phase and exhibit absorbance across the entire visible range of the electromagnetic spectrum. The catalytic potential of the silver oxide was evaluated by following the kinetics of nitrophenol reduction under ambient conditions and is observed to follow pseudo-first order kinetics with the apparent rate constant k a p p = 4 . 24 × 10 - 3 ${{k}_{app}=4.24\ \times {10}^{-3}}$ s-1 at minimum concentration of the catalyst. We attribute the observed catalytic activity to the freshly generated catalytic surface featuring a partially reduced form of silver oxide during reaction. The findings highlight the efficacy of silver oxide in mitigating the environmental pollution originating from the recalcitrant nitroarenes.

A facile green synthesis of gold nanoparticles using Canthium parviflorum extract sustainable and energy efficient photocatalytic degradation of organic pollutants for environmental remediation.

Organic dye and nitrophenol pollution from textiles and other industries present a substantial risk to people and aquatic life. One of the most essential remediation techniques is photocatalysis, which uses the strength of visible light to decolorize water. The present study reports Canthium Parviflorum (CNP) leaf extract utilization as an effective bio-reductant for green synthesis of Au NPs. A simple, eco-friendly process with low reaction time and temperature was adopted to synthesize CNP extract-mediated Au-NPs (CNP-AuNPs). The prepared AuNPs characterization involving X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), energy-dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron microscopy (XPS) surface area analysis, ultraviolet-visible spectroscopy (UV-Vis). XRD results showed that the cubic-structured AuNPs had a crystallite size of 14.12 nm. Assessment of organic dyes performance in degrading brilliant green (BTG) and amido black 10B (AMB) under visible light irradiation highlights an impressive 83.25% and 86% degradation efficiency within 120 min, accompanied by a kinetic rate constant dyes was found to be 0.0828 min⁻1, BTG, and 0.0123 min⁻1, Furthermore, the reduction of 4-nitrophenol by NaBH4 using CNP-AuNPs as a catalyst demonstrated good catalytic performance and rapid degradation at 89.4%. and rate constant 0.099 min-1 followed pseudo-first-order. The LC-MS analysis identified various intermediates during the degradation of the CR dye. Radical trapping experiments suggest that photogenerated free electrons and hydroxyl radicals are crucial for degrading the amido black 10B dye The AuNPs influenced the significant factors responsible for the photocatalytic activity, such as the increase in range of absorbance, increased e- and h+ pair separation, improvement in the charge transfer process, and active site formation, which significantly enhanced the process of degradation. We found that the CNP-AuNPs could effectively remove dyes and nitrophenol from industrial wastewater.

Emulsion Liquid Membranes Based on Os-NP/n-Decanol or n-Dodecanol Nanodispersions for p-Nitrophenol Reduction.

Membrane materials with osmium nanoparticles have been recently reported for bulk membranes and supported composite membrane systems. In the present paper, a catalytic material based on osmium dispersed in n-decanol (nD) or n-dodecanol (nDD) is presented, which also works as an emulsion membrane. The hydrogenation of p-nitrophenol (PNP) is carried out in a reaction and separation column in which an emulsion in the acid-receiving phase is dispersed in an osmium nanodispersion in n-alcohols. The variables of the PNP conversion process and p-aminophenol (PAP) transport are as follows: the nature of the membrane alcohol, the flow regime, the pH difference between the source and receiving phases and the number of operating cycles. The conversion results are in all cases better for nD than nDD. The counter-current flow regime is superior to the co-current flow. Increasing the pH difference between the source and receiving phases amplifies the process. The number of operating cycles is limited to five, after which the regeneration of the membrane dispersion is required. The apparent catalytic rate constant (kapp) of the new catalytic material based on the emulsion membrane with the nanodispersion of osmium nanoparticles (0.1 × 10-3 s-1 for n-dodecanol and 0.9 × 10-3 s-1 for n-decanol) is lower by an order of magnitude compared to those based on adsorption on catalysts from the platinum metal group. The advantage of the tested membrane catalytic material is that it extracts p-aminophenol in the acid-receiving phase.

Facile synthesis of carbon quantum dot/silver nanocomposite and its antimicrobial, catalytic and sensing applications.

Environmentally benign synthesis of nanocomposite, a pivotal facet of nanotechnology, and gaining prominence due to the increasing demand for facile, sustainable, and safe synthesis methods. The present research reports an facile/cost-effective method for the preparation of carbon dots (CDs) and carbon dot silver nanocomposites ( CD@AgNCs) via a hydrothermal treatment of peanut shells. The well-dispersed and spherical CDs with an average diameter of 5-6 nm were obtained and further employed for the preparation of CD@AgNCs. The formation of CD@AgNCs. was confirmed by optical and microscopic studies and ared shift in the λmax from 277 nm (CDs) to 450 nm (CD@AgNCs) with a size range of 30-40 nm was observed. The synthesized CD@AgNCs exhibit excellent catalytic potency for the reduction of 4-nitrophenol to 4-aminophenol, and also displaying a unique interaction and sensing ability towards heavy metal ions (Hg2+), causing a pronounced change in color from reddish-brown to transparent with limit of detection (LOD) of 23.47 ppm. Also, the prepared composite exhibit efficient antimicrobial potential against gram-negative (Escherichia coli) bacteria. Consequently, this study delves into a unified effective remediation platform with the integration of catalysis, sensing, and antimicrobial potentials.

Precipitation of Pt, Pd, Rh, and Ru Nanoparticles with Non-Precious Metals from Model and Real Multicomponent Solutions.

This article presents studies on the precipitation of Pt, Pd, Rh, and Ru nanoparticles (NPs) from model and real multicomponent solutions using sodium borohydride, ascorbic acid, sodium formate, and formic acid as reducing agents and polyvinylpyrrolidone as a stabilizing agent. As was expected, apart from PGMs, non-precious metals were coprecipitated. The influence of the addition of non-precious metal ions into the feed solution on the precipitation yield and catalytic properties of the obtained precipitates was studied. A strong reducing agent, NaBH4 precipitates Pt, Pd, Rh, Fe and Cu NPs in most cases with an efficiency greater than 80% from three- and four-component model solutions. The morphology of the PGMs nanoparticles was analyzed via SEM-EDS and TEM. The size of a single nanoparticle of each precipitated metal was not larger than 5 nm. The catalytic properties of the obtained nanomaterials were confirmed via the reaction of the reduction of 4-nitrophenol (NPh) to 4-aminophenol (NAf). Nanocatalysts containing Pt/Pd/Fe NPs obtained from a real solution (produced as a result of the leaching of spent automotive catalysts) showed high catalytic activity (86% NPh conversion after 30 min of reaction at pH 11 with 3 mg of the nanocatalyst).

The Competition between 4-Nitrophenol Reduction and BH4- Hydrolysis on Metal Nanoparticle Catalysts.

Assessing competitive environmental catalytic reduction processes via NaBH4 is essential, as BH4- is both an energy carrier (as H2) and a reducing agent. A comprehensive catalytic study of the competition between the borohydride hydrolysis reaction (BHR, releasing H2) and 4-nitrophenol reduction via BH4- on M0- and M/M' (alloy)-nanoparticle catalysts is reported. The results reveal an inverse correlation between the catalytic efficiency for BH4- hydrolysis and 4-nitrophenol reduction, indicating that catalysts performing well in one process exhibit lower activity in the other. Plausible catalytic mechanisms are discussed, focusing on the impact of reaction products such as 4-aminophenol and borate on the rate and yield of BH4- hydrolysis. The investigated catalysts were Ag0, Au0, Pt0, and Ag/Pt-alloy nanoparticles synthesized without any added stabilizer. Notably, the observed rate constants for the 4-nitrophenol reduction on Ag0, Ag-Pt (9:1), and Au0 are significantly higher than the corresponding rate constants for BH4- hydrolysis, suggesting that most reductions do not proceed through surface-adsorbed hydrogen atoms, as observed for Pt0 nanoparticles. This research emphasizes the conflicting nature of BH4- hydrolysis and reduction processes, provides insights for designing improved catalysts for competitive reactions, and sheds light on the catalyst properties required for each specific process.

Nickel on Oxidatively Modified Carbon as a Promising Cost-Efficient Catalyst for Reduction of P-Nitrophenol.

The reduction of p-nitrophenol to p-aminophenol has become a benchmark reaction for testing the efficiency of new catalytic systems. In this study, we use oxidatively modified carbon (OMC) as a structural support to develop a new cost-efficient nickel-based catalytic system. The newly developed material comprises single nickel ions, chemically bound to the oxygen functional groups on the OMC surface. The highly oxidized character of OMC ensures the high lateral density of nickel ions on its surface at relatively low nickel content. We demonstrate excellent catalytic properties of the new material by using it as a stationary phase in a prototype of a continuous flow reactor: the reagent fed into the reactor is p-nitrophenol, and the product, exiting the reactor, is the fully converted p-aminophenol. The catalytic properties of the new catalyst are associated with its specific morphology, and with high lateral density of active sites on the surface. The reaction can be considered as an example of single-atom catalysis. The resulting material can be used as an inexpensive but efficient catalyst for industrial wastewater treatment. The study opens the doors for the synthesis of a new series of catalytic systems comprising transition metal atoms on the OMC structural support.

Synthesis by spray pyrolysis of gold nano species confined in iron oxide nanospheres effective in the reduction of 4-nitrophenol to 4-aminophenol.

The highly effective Au/Fe2O3-@Au/Fe2O3nanoreactors for the 4-nitrophenol (4-NP) reduction are successfully obtained by one-pot synthesis using the spray pyrolysis (SP) technique. The Au/Fe2O3-@Au/Fe2O3nanoreactors manifest superior catalytic activity in the reduction of 4-NP in the presence of sodium borohydride (NaBH4) compared to gold-iron oxide nanoreactors prepared via a colloidal approach. The negative effect of the reaction product accumulation, the 4-aminophenol (4-AP), on the catalytic reduction of 4-NP over Au/Fe2O3-@Au/Fe2O3is examined by a direct pre-injection of 4-AP to the reaction media. To the best of our knowledge, it is the first experimental evidence of gold active sites blocking by 4-AP. All obtained samples are characterized by the yolk-shell spherical hollow structure mainly consisted of two embedded hollow nanospheres. The reduction of iron oxide precursor concentration diminishes the diameter of final iron oxide nanospheres. According to STEM-EDS analysis and STEM, Au nano species are uniformly dispersed on both iron oxide nanospheres. The SP technique presently used to synthesize Au/Fe2O3-@Au/Fe2O3nanoreactors manifests high potential for the one-pot fabrication of a large variety of nanoreactors with various active materials applied as heterogeneous catalysts in numerous catalytic processes.

Metal-Organic Framework (MOF)-Derived Electron-Transfer Enhanced Homogeneous PdO-Rich Co3 O4 as a Highly Efficient Bifunctional Catalyst for Sodium Borohydride Hydrolysis and 4-Nitrophenol Reduction.

Developing a bifunctional catalyst with low cost and high catalytic performance in NaBH4 hydrolysis for H2 generation and selective reduction of nitroaromatics will make a significant impact in the field of sustainable energy and water purification. Herein, a low-loading homogeneously dispersed Pd oxide-rich Co3 O4 polyhedral catalyst (PdO-Co3 O4 ) with concave structure is reported by using a metal-organic framework (MOF)-templated synthesis method. The results show that the PdO-Co3 O4 catalyst has an exceptional turnover frequency (3325.6 molH2 min-1 molPd -1 ), low activation energy (43.2 kJ mol-1 ), and reasonable reusability in catalytic H2 generation from NaBH4 hydrolysis. Moreover, the optimized catalyst also shows excellent catalytic performance in the NaBH4 selective reduction of 4-nitrophenol to 4-aminiphenol with a high first-order reaction rate of approximately 1.31 min-1 . These excellent catalytic properties are mainly ascribed to the porous concave structure, monodispersed Pd oxide, as well as the unique synergy between PdO and Co3 O4 species, which result in a large specific surface area, high conductivity, and fast solute transport and gas emissions.

Highly secretory expression of recombinant cowpea chlorotic mottle virus capsid proteins in Pichia pastoris and in-vitro encapsulation of ruthenium nanoparticles for catalysis.

The applications of viral protein cages have expanded rapidly into the fields of bionanotechnology and materials science. However, the low-cost production of viral capsid proteins (CPs) on a large scale is always a challenge. Herein, we develop a highly efficient expression system by constructing recombinant Pichia pastoris cells as a "factory" for the secretion of soluble cowpea chlorotic mottle virus (CCMV) CPs. Under optimal induction conditions (0.9 mg/mL of methanol concentration at 30 °C for 96 h), a high yield of approximately 95 mg/L of CCMV CPs was harvested from the fermentation supernatant with CPs purity >90%, which has significantly simplified the rest of the purification process. The resultant CPs are employed to encapsulate Ruthenium (Ru) nanoparticles (NPs) via in-vitro self-assembly to prepare hybrid nanocatalyst, i.e. Ru@virus-like particles (VLPs). The catalytic activity over Ru@VLPs was evaluated by reducing 4-nitrophenol (4-NP) to 4-aminophenol (4-AP). The results indicate that, with the protection of protein cages, Ru NPs were highly stabilized during the catalytic reaction. This results in enhanced catalytic activity (reaction rate constant k = 0.14 min-1) in comparison with unsupported citrate-stabilized Ru NPs (Ru-CA) (k = 0.08 min-1). Additionally, comparatively lower activation energy over Ru@VLPs (approximately 32 kJ/mol) than that over Ru-CA (approximately 39 kJ/mol) could be attributed to the synergistic effect between Ru NPs and some functional groups such as amino groups (-NH2) on CPs that weakened the activation barrier of 4-NP reduction. Therefore, enhanced activity and decreased activation energy over Ru@VLPs demonstrated the superiority of Ru@VLPs to unsupported Ru-CA.

Development of a Simple Reversible-Flow Method for Preparation of Micron-Size Chitosan-Cu(II) Catalyst Particles and Their Testing of Activity.

A simple flow system employing a reversible-flow syringe pump was employed to synthesize uniform micron-size particles of chitosan-Cu(II) (CS-Cu(II)) catalyst. A solution of chitosan and Cu(II) salt was drawn into a holding coil via a 3-way switching valve and then slowly pumped to drip into an alkaline solution to form of hydrogel droplets. The droplets were washed and dried to obtain the catalyst particles. Manual addition into the alkaline solution or employment of flow system with a vibrating rod, through which the end of the flow line is inserted, was investigated for comparison. A sampling method was selected to obtain representative samples of the population of the synthesized particles for size measurement using optical microscopy. The mean sizes of the particles were 880 ± 70 µm, 780 ± 20 µm, and 180 ± 30 µm for the manual and flow methods, without and with the vibrating rod, respectively. Performance of the flow methods, in terms of rate of droplet production and particle size distribution, are discussed. Samples of 180 µm size CS-Cu(II) particles were tested for catalytic reduction of 0.5 mM p-nitrophenol to p-aminophenol by 100-fold excess borohydride. The conversion was 98% after 20 min, whereas without the catalyst there was only 14% conversion.

Gum Kondagogu/Reduced Graphene Oxide Framed Platinum Nanoparticles and Their Catalytic Role.

This study investigates an environmentally benign approach to generate platinum nanoparticles (Pt NP) supported on the reduced graphene oxide (RGO) by non-edible gum waste of gum kondagogu (GK). The reaction adheres to the green chemistry approach by using an aqueous medium and a nontoxic natural reductant-GK-whose abundant hydroxyl groups facilitate in the reduction process of platinum salt and helps as well in the homogenous distribution of ensued Pt NP on RGO sheets. Scanning Electron Microscopy (SEM) confirmed the formation of kondagogu gum/reduced graphene oxide framed spherical platinum nanoparticles (RGO-Pt) with an average particle size of 3.3 ± 0.6 nm, as affirmed by Transmission Electron Microscopy (TEM). X-ray Diffraction (XRD) results indicated that the Pt NPs formed are crystalline with a face-centered cubic structure, while morphological analysis by XRD and Raman spectroscopy revealed a simultaneous reduction of GO and Pt. The hydrogenation of 4-nitrophenol could be accomplished in the superior catalytic performance of RGO-Pt. The current strategy emphasizes a simple, fast and environmentally benign technique to generate low-cost gum waste supported nanoparticles with a commendable catalytic activity that can be exploited in environmental applications.

Preparation of Magnetic CuFe2O4@Ag@ZIF-8 Nanocomposites with Highly Catalytic Activity Based on Cellulose Nanocrystals.

A facile approach was successfully developed for synthesis of cellulose nanocrystals (CNC)-supported magnetic CuFe2O4@Ag@ZIF-8 nanospheres which consist of a paramagnetic CuFe2O4@Ag core and porous ZIF-8 shell. The CuFe2O4 nanoparticles (NPs) were first prepared in the presence of CNC and dispersant. Ag NPs were then deposited on the CuFe2O4/CNC composites via an in situ reduction directed by dopamine polymerization (PDA). The CuFe2O4/CNC@Ag@ZIF-8 nanocomposite was characterized by TEM, FTIR, XRD, N2 adsorption-desorption isotherms, VSM, and XPS. Catalytic studies showed that the CuFe2O4/CNC@Ag@ZIF-8 catalyst had much higher catalytic activity than CuFe2O4@Ag catalyst with the rate constant of 0.64 min-1. Because of the integration of ZIF-8 with CuFe2O4/CNC@Ag that combines the advantaged of each component, the nanocomposites were demonstrated to have an enhanced catalytic activity in heterogeneous catalysis. Therefore, these results demonstrate a new method for the fabrication of CNC-supported magnetic core-shell catalysts, which display great potential for application in biocatalysis and environmental chemistry.

Performance of Preformed Au/Cu Nanoclusters Deposited on MgO Powders in the Catalytic Reduction of 4-Nitrophenol in Solution.

The deposition of preformed nanocluster beams onto suitable supports represents a new paradigm for the precise preparation of heterogeneous catalysts. The performance of the new materials must be validated in model catalytic reactions. It is shown that gold/copper (Au/Cu) nanoalloy clusters (nanoparticles) of variable composition, created by sputtering and gas phase condensation before deposition onto magnesium oxide powders, are highly active for the catalytic reduction of 4-nitrophenol in solution at room temperature. Au/Cu bimetallic clusters offer decreased catalyst cost compared with pure Au and the prospect of beneficial synergistic effects. Energy-dispersive X-ray spectroscopy coupled with aberration-corrected scanning transmission electron microscopy imaging confirms that the Au/Cu bimetallic clusters have an alloy structure with Au and Cu atoms randomly located. Reaction rate analysis shows that catalysts with approximately equal amounts of Au and Cu are much more active than Au-rich or Cu-rich clusters. Thus, the interplay between the Au and Cu atoms at the cluster surface appears to enhance the catalytic activity substantially, consistent with model density functional theory calculations of molecular binding energies. Moreover, the physically deposited clusters with Au/Cu ratio close to 1 show a 25-fold higher activity than an Au/Cu reference sample made by chemical impregnation.

In Situ Growth of Pd Nanosheets on g-C3 N4 Nanosheets with Well-Contacted Interface and Enhanced Catalytic Performance for 4-Nitrophenol Reduction.

Loading novel metal nanosheets onto nanosheet support can improve their catalytic performance, but the morphological incompatibility makes it difficult to construct a well-contacted interface, which is of particular interest in supported catalysts. Herein, Pd nanosheets (Pd NSs) are supported onto graphitic carbon nitride nanosheets (CNNSs) with intimate face-to-face contact through an in situ growth method. This method overcomes the limitations of the morphological incompatibility and ensures the intimate interfacial contact between Pd NSs and CNNSs. The nitrogen-rich nature of CNNSs endows Pd NSs with abundant anchoring sites, which optimizes the electronic structure and improves the chemical and morphological stability of Pd NSs. The supported Pd NSs demonstrate high dispersion and exhibit largely enhanced activity toward the reduction of 4-nitrophenol. The concentration-normalized rate constant is up to 3052 min-1 g-1 L, which is 5.4 times higher than that obtained by unsupported Pd NSs. No obvious deactivation is observed after six runs of the recycling experiments. It is believed that the supported novel metal nanosheets with the intimately contacted interface may show promising applications in catalysis.

High Catalytic Efficiency of Nanostructured ß-CoMoO4 in the Reduction of the Ortho-, Meta- and Para-Nitrophenol Isomers.

Nanostructured ß-CoMoO4 catalysts have been prepared via the thermal decomposition of an oxalate precursor. The catalyst was characterized by infrared spectroscopy (FTIR), X-ray diffraction (XRD), Brunauer-Emmett-Teller method (BET), energy dispersive X-ray spectroscopy (EDX), and transmission electron microscopy (TEM). The efficiency of these nanoparticles in the reduction of ortho- and meta-nitrophenol isomers (2-NP, 3-NP, and 4-NP) to their corresponding aminophenols was tested using UV-visible spectroscopy measurements. It was found that, with a ß-CoMoO4 catalyst, NaBH4 reduces 3-NP instantaneously, whilst the reduction of 2-NP and 4-NP is slower at 8 min. This difference is thought to arise from the lower acidity of 3-NP, where the negative charge of the phenolate could not be delocalized onto the oxygen atoms of the meta-nitro group.

Preparation and Characterization of α-Zinc Molybdate Catalyst: Efficient Sorbent for Methylene Blue and Reduction of 3-Nitrophenol.

Zinc molybdate (ZnMoO4) was prepared by thermal decomposition of an oxalate complex under a controlled temperature of 500 °C. Analyses of the oxalate complex were carried out using Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). On the other hand, analyses of the synthesized zinc molybdate were carried out by X-ray diffraction (XRD), transmission electron microscopy (TEM), and Brunauer-Emmett-Teller technique (BET). The efficiency of the synthesized catalyst was tested with the reduction reaction of 3-nitrophenol (3-NP), and was also applied as a sorbent for methylene blue dye (MB) in aqueous solutions. The catalytic test of zinc molybdate shows a very high activity. The concentration reduction progress and adsorption of the dye were followed by an ultraviolet-visible (UV-vis) spectrophotometer.

Retraction: Gold nanoparticles immobilized on electrospun titanium dioxide nanofibers for catalytic reduction of 4-nitrophenol.

This study involves the preparation and catalytic properties of anatase titanium dioxide nanofibers (TiO2 NFs) supported gold nanoparticles (Au NPs) using a model reaction based on the reduction of 4-nitrophenol (NP) into 4-aminophenol (AP) by sodium borohydride (NaBH4). The fabrication of surfactant-free Au NPs was performed using pulsed laser ablation in liquid (PLAL) technique. The TiO2 NFs were fabricated by a combination of electrospinning and calcination process using a solution containing poly(vinyl pyrolidone)(PVP) and titanium isopropoxide. The adsorption efficiency of laser-generated surfactant-free Au NPs to TiO2 NF supports as a function of pH was analyzed. Our results show that the electrostatic interaction mainly controls the adsorption of the nanoparticles. Au NPs/TiO2 NFs composite exhibited good catalytic activity for the reduction of 4-NP to 4-AP. The unique combination of these materials leads to the development of highly efficient catalysts. Our heterostructured nanocatalysts possibly form an efficient path to fabricate various metal NP/metal-oxide supported catalysts. Thus the applications of PLAL-noble metal NPs can widely broaden.

Formation of iron oxide/Pd hybrid nanostructures with enhanced peroxidase-like activity and catalytic reduction of 4-nitrophenol.

Iron oxide/Pd hybrid nanostructures with controllable Pd loading from 0.05 to 1.0 (calculated as Pd/Fe molar ratio) have been synthesized by chemical reduction of Pd2+ on iron oxide particles. The combination of iron oxide and Pd exhibits enhanced peroxidase-like activity and catalytic activity toward reduction of 4-nitrophenol. The catalytic enhancements were found to be dependent on the Pd loading amount as well as the synergistic effect between iron oxide and Pd. These results suggest that iron oxide with unique surface chemical state can be an active supporter and suggest an effective way to design superior hybrid nanostructures for catalytic applications.