High-performance Nanocatalyst Research Articles

Ultrafast degradation of methylene blue from aqueous media by Fe3O4/rGO/SiO2 magnetic nanocomposite in dark catalyst process

Water pollution by organic dyes has been one of the great challenges in recent days. The application of nanostructure and nanocatalyst for the degradation of organic dyes is a very effective and useful method for the treatment of water and industrial wastewater. In this research, Fe3O4/rGO/SiO2 dark catalyst nanomaterial was used to remove methylene blue dye from aqueous media. The Fe3O4/rGO/SiO2 nanocatalyst was prepared by an ultrasonic probe approach. The physical, chemical, and morphology properties of synthesized Fe3O4/rGO/SiO2 nanocomposites were investigated by transmission electron microscopy (TEM), energy X-ray dispersion (EDS), Fourier Transform infrared (FT-IR), vibrating sample magnetometer (VSM), Raman, field emission scanning electron microscopy (FESEM), and X-ray diffraction (XRD) analysis. XRD, FT-IR, and Raman analysis results confirmed the successful formation of Fe3O4/rGO/SiO2 structure. VSM analysis results showed that Fe3O4/rGO/SiO2 nanocomposites had good superparamagnetic behavior with a magnetization saturation of 40 emu/g. TEM and FESEM results showed that SiO2 and Fe3O4 were grown on rGO nanosheets, spherically. The Fe3O4/rGO/SiO2 nanocomposites had excellent catalyst activity and methylene blue dye completely degraded in 4 min. The radical scavenger experiment and Zeta potential analysis confirmed that surface electrons of Fe3O4/rGO/SiO2 nanocomposites had an essential role in the dark catalyst activity of Fe3O4/rGO/SiO2 nanocomposite. The experimental results confirmed that Fe3O4/rGO/SiO2 magnetic nanocomposites have good potential to be used as a recyclable and high-performance nanocatalyst for the treatment of water from methylene blue dye.

Upcycling Waste Snail Shells into High-Performance Nanocatalyst for Optimized Biodiesel Production: A Sustainable Approach

The transesterification of soybean oil (SO) to biodiesel utilizing a basic CaO nanocatalyst derived from waste snail shells has been reported in this work. The steady rise in greenhouse gas emissions contributes to environmental pollution, posing a significant threat to human life due to the escalating rates of petroleum consumption worldwide. Thus, biodiesel appears as a potential liquid fuel for replacing petroleum diesel. Here we have utilized waste snail shells as a cost-effective material which will reduce the overall biodiesel manufacturing cost. We obtained a remarkable biodiesel yield of 96.1 % with a very low activation energy (30.45 kJ mol−1). The catalyst displayed exceptional stability, maintaining consistent catalytic activity over six consecutive cycles without experiencing a notable decline. Using life cycle cost analysis (LCCA) it has been discovered that the estimated cost of producing 1kg of biodiesel is merely $ 0.935, highlighting its robust potential for extensive commercial adoption.

Photocatalytic oxidative demercaptanization/denitrogenation of gasoline catalyzed by MAX-phase@rGO@PW11Zn as a high-performance nanocatalyst

The new catalyst (assigned as MAX-phase@rGO@PW11Zn) was prepared based on [(n‐C4H9)4N][PW11ZnO39] (PW11Zn), Ti3AlC2 (MAX-phase), reduced graphene oxide (rGO) and used in photocatalytic oxidative denitrogenation (photocatalytic-ODN) and demercaptanization (photocatalytic-ODS). The photocatalysis process adjusted to demercaptanization of real gasoline and oxidation of model fuel (thiophene (TH) and pyridine (PY)). Intercalation effect of PW11Zn to Ti3AlC2 MAX-phase and reduced graphene oxide accelerate electron transfer and prevent the recombining of electron-hole pairs. MAX-phase@rGO@PW11Zn catalyst exhibited enhanced photocatalytic application and excellent reusability in the elimination of TH and PY, and producing ultra-clean fuels: 97.72% and 98.94% efficiency were achieved for thiophene (TH) and pyridine (PY), respectively at 35 °C. The good activity of MAX-phase@rGO@PW11Zn/H2O2/CH3COOH proves that this photocatalytic system can be a promising strategy for a high-performance catalyst for the generation of ultra‐low‐sulfur gasoline.

Synthesis and characterization of new nanocomposite based on di-substituted Keggin-type phosphotungstate@ceramic as a new and high-performance nanocatalyst for O2 evolution from water oxidation reaction

In this research, a new nanocomposite was synthesized via the sol-gel method by covalent immobilizing of di-substituted Keggin-type heteropolyanion containing cobalt (PW10Co2) on the surface of manganese oxide (MnO2) ceramic. The desired nanocomposite (PW10Co2@MnO2) was used as an effective heterogeneous catalyst in the water oxidation reaction for oxygen evolution. The PW10Co2@MnO2 nanocatalyst was identified through Fourier transform infrared (FT-IR), ultraviolet–visible (UV–vis), X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray (EDX) methods in detail. After confirming the preparation of the PW10Co2@MnO2, its catalytic activity in the water splitting reaction was assessed in the presence of cerium (Ⅳ) ammonium nitrate (CAN) as an efficient oxidant at different pH (pH = 7 and 9). The PW10Co2@MnO2 nanocatalyst demonstrated turnover number (TON), turnover frequency (TOF), and O2 evolution of 520.12 mmolO2molCo.s, 178 mmolO2molCo, and 0.003 mgO2L.S, respectively, which are the highest values at pH = 9 in the water oxidation process. Moreover, the effect of CAN concentration, pH, and the amount of KOH was assessed on the catalytic activity, and a plausible reaction mechanism was proposed. In the present study, the PW10Co2@MnO2 nanocatalyst provides valuable insights into the design of other catalysts for the water oxidation reaction and beyond.

Palladium doped with boron and phosphorus on activated carbon: a high-performance nanocatalyst for the hydrogenation of alkenes

Fabrication of high-performance palladium on activated carbon (Pd/AC) nanocatalysts for hydrogenation of alkenes to reduce the cost of reaction products has always been of interest to researchers and industries. Herein, the purpose was the step-by-step investigation of the simple precipitation-reduction method to determine the best chemicals usable in producing the high-performance 10%Pd/AC nanocatalyst for the hydrogenation of alkenes. Hence, different types of carbon supports, alkaline agents, and reducing agents were selected for this purpose. Catalytic hydrogenation of cinnamic acid to hydrocinnamic acid was used as a well-known standard test for evaluating the activity of the nanocatalysts. The AC prepared by pine wood, H2PdCl4, KHCO3, and NaBH4/NaH2PO2 were the most suitable materials for producing high-performance Pd/AC using the mentioned method. It was specified that activity is increased with the lower amount of oxygenated acidic functional groups on the AC, greater cation radius of the alkaline agent, weaker alkaline agent, and higher reduction power of the reducing agent. NaH2PO2 and especially NaBH4 increase the activity more than other reducing agents because of their high reduction power and adding phosphorus (P) and boron (B) to Pd, respectively. Three nanocatalysts with the most activity were chosen for more investigations by different analyses. The results of these analyses were according to the procedure obtained for their catalytic activity. The reusability test of chosen nanocatalysts indicated that the stability of Pd/AC is increased by doping the Pd with B and especially P. According to the obtained results, Pd nanocatalyst doped with both P and B is strongly recommended for application in alkenes hydrogenation.

Green synthesis of Ag ultra-fine nano-catalyst supported on layered double oxide and chitosan: Accelerated reduction of 4-nitrophenol to 4-aminophenol

In this research, the green synthesis of a silver nanoparticle (Ag NPs) based nano-catalyst for reducing 4-nitrophenol (4-NP) pollutants were explained. Hence, instead of using chemical reductant, natural extract of green tea was utilized as reducing agent to prepare Ag NPs. The obtained Ag NPs had uniform size and shape. The small size of Ag NPs helps exited electron to be stabilized and extends lifespan during a reduction reaction. Then, layered double hydroxides (LDHs) was prepared, and after calcination was added to Ag NPs. The calcination of LDH leads to a significant increase in the number of catalytic active sites, thereby enhancing catalyst function. Besides, chitosan (CS) was chosen as a natural polymer matrix. Ag-LDH hybrids can remain immobilized and well-dispersed on CS matrix. The CS matrix also facilitates the separation process. More importantly, it enhances reusability of the nano-catalyst noticeably and accordingly plays an important role in the synthesis of the reusable high-performance nano-catalyst. Finally, the prepared CS/Ag-LDH NC film reduced 4-NP to 4–aminophenol in 5 min with a conversion percentage of 99.01% ± 0.13. The effect of various parameters like pH, catalyst amount, NaBH4 concentration, and 4-NP concentration was evaluated. Based on the obtained findings, reaction kinetics is pseudo-first-order with an apparent rate constant of 1.65 × 10−2 (s−1), and the activation energy was calculated to be 13.93 kJ mol−1. Presence of CS enhanced reusability of the nano-catalyst noticeably so that, performance of the nano-catalyst remained unchanged after five reuse cycles.

Microwave-assisted synthetic method of novel Bi2O3 nanostructure and its application as a high-performance nano-catalyst in preparing benzylidene barbituric acid derivatives.

In this study, controllable and optimal microwave irradiation has been used to synthesize the novel nanostructures of Bi2O3 under environmental conditions. The final products had a thermal stability of 210°C, an average particle size distribution of 85 nm, and a surface area of 783 m2/g. The high thermodynamic stability of Bi2O3 nanostructures was confirmed by TG and differential scanning calorimetry (DSC) analyses. The nanostructure nature of compounds, and most importantly, the use of an effective, cost-effective, and rapid synthesis route of microwave have created significant physiochemical properties in the Bi2O3 products. These unexpected properties have made the possibility of potential application of these products in various fields, especially in nano-catalyst applications. It is well-documented that, as Lewis acid, bismuth nano-catalyst exhibits a great catalytic activity for the green synthesis of some bio-active barbituric acid derivatives using precursors with electron-donating or electron-withdrawing nature in high yields (80%–98%). After incorporating this catalyst into the aqueous media, all the reactions were completed within 2–3 min at room temperature. The main advantages of this method are practical facility, the availability of starting materials, and low costs besides the catalyst reusability. Additionally, the catalyst synthesis process may be carried out in the aqueous media for a short period with medium to high yields. The obtained results have opened a new window for the development of a novel nano-catalyst with practical application.

Exploring the In Situ Formation Mechanism of Polymeric Aluminum Chloride-Silica Gel Composites under Mechanical Grinding Conditions: As a High-Performance Nanocatalyst for the Synthesis of Xanthene and Pyrimidinone Compounds.

The use of mechanical ball milling to facilitate the synthesis of organic compounds has attracted intense interest from organic chemists. Herein, we report a new process for the preparation of xanthene and pyrimidinone compounds by a one-pot method using polymeric aluminum chloride (PAC), silica gel, and reaction raw materials under mechanical grinding conditions. During the grinding process, polymeric aluminum chloride and silica gel were reconstituted in situ to obtain a new composite catalyst (PAC–silica gel). This catalyst has good stability (six cycles) and wide applicability (22 substrates). The Al–O–Si active center formed by in situ grinding recombination was revealed to be the key to the effective catalytic performance of the PAC–silica gel composites by the comprehensive analysis of the catalytic materials before and after use. In addition, the mechanism of action of the catalyst was verified using density functional theory, and the synthetic pathway of the xanthene compound was reasonably speculated with the experimental data. Mechanical ball milling serves two purposes in this process: not only to induce the self-assembly of silica and PAC into new composites but also to act as a driving force for the catalytic reaction to take place. From a practical point of view, this “one-pot” catalytic method eliminates the need for a complex preparation process for catalytic materials. This is a successful example of the application of mechanochemistry in materials and organic synthesis, offering unlimited possibilities for the application of inorganic polymer materials in green synthesis and catalysis promoted by mechanochemistry.

From a Chemotherapeutic Drug to a High-Performance Nanocatalyst: A Fast Colorimetric Test for Cisplatin Detection at ppb Level.

A rapid point-of-care method for the colorimetric detection of cisplatin was developed, exploiting the efficient conversion of the chemotherapeutic drug into a high-performance nanocatalyst with peroxidase enzyme mimics. This assay provides high specificity and ppb-detection sensitivity with the naked eye or a smartphone-based readout, outperforming many standard laboratory-based techniques. The nanocatalyst-enabled colorimetric assay can be integrated with machine-learning methods, providing accurate quantitative measurements. Such a combined approach opens interesting perspectives for the on-site monitoring of both chemotherapeutic patients to achieve optimal treatments and healthcare workers to prevent their unsafe exposure.

Synthesis and characterization of a new hybrid nanocomposite based on di-substituted heteropolyanion-quantum dots as a high-performance nanocatalyst for organic dye removal from wastewater

In this manuscript, a new hybrid nanocatalyst (PMo10Ni2/ZnS@CS) based on di-substituted heteropolyanion (PMo10Ni2) and ZnS quantum dot was synthesized via the hydrothermal method. PMo10Ni2/ZnS@CS is a candidate for removal of environmental pollutants. The synthesized hybrid nanocatalyst was analyzed by TEM, UV-vis, FT-IR, XRD, and EDX techniques. The results of XRD analysis showed the average crystallite size of the PMo10Ni2/ZnS@CS nanocomposite particles is about 33 nm, which was consistent with the TEM results. The nano-catalytic activity of PMo10Ni2/ZnS@CS hybrid nanocomposite was investigated in photocatalytic decolorization of organic dyes. The experimental results showed that the inorganic-organic hybrid nanocomposite (PMo10Ni2/ZnS@CS) had excellent photocatalytic efficiency with 98% dye removal. The recovery of the photocatalyst in the decolorization process was investigated and the results indicate a reduction of photocatalytic power after the second and third stage recovery, respectively. In the present study, PMo10Ni2/ZnS@CS was proposed as a heterogeneous nanocatalyst with broad nanocatalytic applications of dye removal.

Biodiesel production from waste cooking oil using heterogeneous nanocatalyst-based magnetic polyaniline decorated with cobalt oxide

The development of novel heterogeneous catalyst materials with unique chemical/physical properties has attracted great attention in biodiesel production. Herein, the binary functional organic–inorganic nanocomposite based on polyaniline decorated with magnetic iron oxide and cobalt oxide nanoparticles were used to synthesis MPANI@Co3O4 as novel nanocatalyst. The proposed material was fabricated through a facile hydrothermal technique coupled with a one-pot polymerization method. The morphology and structure of as-prepared MPANI@Co3O4 materials were evaluated using field-emission scanning electron microscope (FESEM), Fourier transform infrared spectroscopy (FTIR), vibrating-sample magnetometer (VSM), and energy dispersive X-Ray spectrometer (EDX). The FESEM-EDX provided the metal oxide nanoparticles well incorporated onto polyaniline with C (28.32 %), N (48.45 %), O (21.44 %), Fe (1.69 %), and Co (1.10 %). The MPANI@Co3O4 was successfully used as a high-performance nanocatalyst in transesterification of waste cooking oil (WCO) to FAMEs (biodiesel). Due to the acidic-alkaline nature of the proposed catalyst, it has high potential to produce methoxy ions followed by attacking the carbonyl groups of triglycerides. In further experiments, the satisfactory reaction conditions obtained were MPANI to Co3O4 ratio of 1:1, WCO to methanol molar ratio of 1:10, 240 min reaction time and at 90 °C reaction temperature. Moreover, under optimum conditions, the catalyst offered desirable catalytic performance (>93%) to catalyze the triglycerides of WCO to biodiesel (FAMEs). Therefore, the novel binary organic–inorganic nanocomposite can be used as co-catalyst material in biodiesel processing.

Improvement of Steam Injection Processes Through Nanotechnology: An Approach through in Situ Upgrading and Foam Injection

This study aims to evaluate a high-performance nanocatalyst for upgrading of extra-heavy crude oil recovery and at the same time evaluate the capacity of foams generated with a nanofluid to improve the sweeping efficiency through a continuous steam injection process at reservoir conditions. CeO2±δ nanoparticles functionalized with mass fractions of 0.89% and 1.1% of NiO and PdO, respectively, were employed to assist the technology and achieve the oil upgrading. In addition, silica nanoparticles grafted with a mass fraction of 12% polyethylene glycol were used as an additive to improve the stability of an alpha-olefin sulphonate-based foam. The nanofluid formulation for the in situ upgrading process was carried out through thermogravimetric analysis and measurements of zeta potential during eight days to find the best concentration of nanoparticles and surfactant, respectively. The displacement test was carried out in different stages, including, (i) basic characterization, (ii) steam injection in the absence of nanofluids, (iii) steam injection after soaking with nanofluid for in situ upgrading, (iv) N2 injection, and (v) steam injection after foaming nanofluid. Increase in the oil recovery of 8.8%, 3%, and 5.5% are obtained for the technology assisted by the nanocatalyst-based nanofluid, after the nitrogen injection, and subsequent to the thermal foam injection, respectively. Analytical methods showed that the oil viscosity was reduced 79%, 77%, and 31%, in each case. Regarding the asphaltene content, with the presence of the nanocatalyst, it decreased from 28.7% up to 12.9%. Also, the American Petroleum Institute (API) gravity values increased by up to 47%. It was observed that the crude oil produced after the foam injection was of higher quality than the crude oil without treatment, indicating that the thermal foam leads to a better swept of the porous medium containing upgraded oil.

Facile Fabrication of Novel Hetero-Structured Organic–Inorganic High-Performance Nanocatalyst: A Smart System for Enhanced Catalytic Activity toward Ciprofloxacin Degradation and Oxygen Reduction

In this study, a novel organic–inorganic polyaniline/silver/silver molybdate (PANI/Ag/Ag2MoO4) heterojunction nanocatalyst has been fabricated by in situ depositing Ag2MoO4 on p-type PANI to explore two different catalytic properties, e.g., photocatalytic degradation of antibiotic ciprofloxacin (CIP) and electrocatalytic reduction of oxygen. After hybridization of Ag2MoO4 with PANI, the p-n heterojunction developed and consequently z-scheme induced efficient photogenerated charge carrier separation and migration occur due to the internal electric field developed at the heterojunction interface. Compared with pure Ag2MoO4, the heterojunction nanocomposite possessed significantly enhanced photocatalytic activity as evidenced by the degradation of Congo Red (CR) dye under UV light irradiation. The optimum composite with 20 wt % PANI nanorods exhibited paramount photocatalytic activity over all the composites. Subsequently, 99.99% of CIP removal was achieved with this optimal composite within 40 min. On the o...

Novel Z-scheme composite Ag2CrO4/NG/polyimide as high performance nano catalyst for photoreduction of CO2: Design, fabrication, characterization and mechanism

The evolution of new Z-scheme composites aids to solve the increasing energy demand via artificial photosynthesis. This research introduced novel Z-scheme nanocomposite, Ag2CrO4/nitrogen-doped graphene /Polyimide (Ag2CrO4/NG/PI), and its photocatalytic activity in CO2 reduction under simulated sunlight irradiation. The nanocomposite was prepared with ultrasound-assisted in-situ deposition of different amounts of Ag2CrO4-NPs on NG/ PI and completely characterized using various techniques such as AFM, FE-SEM, XPS, XRD, FT-IR, DRS and PL which confirmed the presence of Ag2CrO4, NG and PI in the composite structure. The photocatalytic investigations showed a significant promotion for light absorption ability of Ag2CrO4 on NG and PI. The high performance photocatalytic activity of Ag2CrO4/NG/PI can be interpreted by the gap of EHPs in the photocatalyst as a Z-scheme due to the construction of hetero-linkage structure between Ag2CrO4 and PI. Meanwhile, the presence of the pyridinic N as an unique selective site toward CO generation, can reduce the free energy barrier for the potential-limiting step to compose important intermediates which lead to high-efficiency photocatalyst activity. The optimal Ag2CrO4/NG/PI (25AN) photocatalyst presented a CO2 photoreduction rate of 352.1 μmol h−1·gcat −1, which was higher than previously reported works under similar condition. This investigation introduces a novel photocatalyst nanocomposite of the, Ag2CrO4/NG/PI, in concurrent natural resources conservation and green productivity.

One-step hydrothermal synthesis of MoNiCoS nanocomposite hybridized with graphene oxide as a high-performance nanocatalyst toward methanol oxidation

A carbon based nanocatalyst in the form of graphene hybridized MoNiCoS (MoNiCoS/Go) was synthesized in a single step hydrothermal method for methanol oxidation in a direct methanol fuel cell, as a substitution for expensive and rare platinum. The results obtained from methanol oxidation over the graphene hybridized MoNiCoS modified electrode revealed suitable electrocatalytic properties and a considerable diffusion current, confirmed by the Tafel plots through calculating the exchange current (io) as an important kinetic parameter of electron transfer. It was found that the above composite could be an appropriate alternative in designing a DMFC fuel cell as a clean energy generator.

High-Performance Nanocatalyst for Adsorptive and Photo-Assisted Fenton-Like Degradation of Phenol: Modeling Using Artificial Neural Networks

High-performance activated carbon-zinc oxide (Ac–ZnO) nanocatalyst was fabricated via the microwave-assisted technique. Ac–ZnO was characterized and the results indicated that Ac–ZnO is stable, had a band gap of 3.26 eV and a surface area of 603.5 m2g−1, and exhibited excellent adsorptive and degrading potentials. About 93% phenol was adsorbed within 550 min of reaction by Ac–ZnO. Impressively, a complete degradation was achieved in 90 min via a photo-Fenton/Ac–ZnO system under optimum conditions. An artificial neural network (ANN) model was developed and applied to study the relative significance of input variables affecting the degradation of phenol in a photo-Fenton process. The ANN results indicate that increases in both H2O2 and Ac–ZnO dosage enhanced the rate of phenol degradation. The highest rate constant at the optimum conditions was 0.093 min−1 and it was found to be consistent with the ANN-predicted rate constant (0.095 min−1).

Mono Mn(II)-substituted phosphotungstate@modified graphene oxide as a high-performance nanocatalyst for oxidative demercaptanization of gasoline

Abstract In this study, the removal of hazardous sulfur compounds from gasoline was provided based on catalytic oxidation demercaptanization technique. The cesium salt of mono Mn(II)-substituted Keggin-type polyoxometalate Cs5PMnW11O39 (PMnW11) was successfully synthesized and immobilized on modified graphene oxide (mGO) as a new nanocatalyst (PMnW11@mGO) for demercaptanization process. The synthesized materials were characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), ultraviolet–visible (UV–vis), Fourier transform infrared spectroscopy (FT-IR), and cyclic voltammetry (CV) analysis. Characterization of the prepared nanocomposite was confirmed that the structures of the PMnW11 and mGO were retained after immobilization. The sulfur-containing molecules in real gasoline and simulated fuel were oxidized and extracted efficiently under mild reaction condition. After treatment, the mercaptans and total sulfur content of real gasoline were lowered with 98.8% and 98% yield, respectively. The PMnW11@mGO hybrid nanocatalyst was separated and reused conveniently at the end of the reaction for five times. The excellent performance of this new catalytic oxidation system can be a promising rout to achieve ultra-clean gasoline.

Nitrogen doped graphene nanosheet supported platinum nanoparticles as high performance electrochemical homocysteine biosensors.

Functional carbon nanomaterials are significantly important for the development of high performance sensitive and selective electrochemical biosensors. In this study, graphene supported platinum nanoparticles (GN-PtNPs) and nitrogen doped graphene supported platinum nanoparticles (N-GN-PtNPs) were synthesized by a simple chemical reduction method and explored as high performance nanocatalyst supports, as well as doped nanocatalyst supports, toward electrochemical oxidation of homocysteine (HCY) for the first the time. Our studies demonstrate that N-doped graphene supported PtNPs show higher electrocatalytic activity for HCY with an experimental detection limit of 200 pM. Moreover, N-doped graphene supported Pt was demonstrated to have excellent selectivity in the electrochemical oxidation of HCY i.e., the detection of HCY is successful in the presence of a 20-fold excess of ascorbic acid (AA). The practical application of N-doped graphene supported PtNP materials is effectively shown for the determination of HCY in both human blood serum and urine samples, by differential pulse voltammetry under optimized conditions. Our findings conclude that N-doped graphene supported PtNPs can be developed as a high performance and versatile nano-electrocatalyst for electrochemical biosensor applications.