Catalytic Reduction Efficiency Research Articles

Uncovering the discharge structure evolution and electrochemical performance of sulfur cathode host 2D-Fe0.89M0.11S2 (M = Ti, V)

The sulfur cathode host materials with excellent electronic conductivity and catalytic performance are the key to highly efficient Li-S redox chemistry for the lithium‑sulfur batteries (LSBs). Although 2D-FeS2 as sulfur cathode host shows high theoretical capacity and flat voltage plateaus, the Li-S redox chemical reaction mechanism is still unclear. By using the first-principles calculations, the formation energy, working voltage, theoretical capacity, electronic conductivity, adsorption performance, electrocatalytic mechanism, Li+ diffusion and Li2S decomposition barrier of 2D-FeS2 and M (M = Ti, V) doped 2D-FeS2 are investigated to evaluate its physicochemical properties. 2D-Fe0.89M0.11S2 is thermodynamically stable due to its low lattice distortion, formation energy and mixing enthalpy. The charging voltage of 2D-Fe0.89Ti0.11S2 is better than that of 2D-Fe0.89V0.11S2, but the charging voltage step is reversed. The electrical conductivity of 2D-Fe0.89M0.11S2 is superior to 2D-FeS2. The closer the highest molecule occupied orbitals is to the Fermi level, the lower the discharge voltage will be. 2D-Fe0.89V0.11S2 and its discharge structure 2D-Li2Fe0.89V0.11S2 improve the efficiency of catalytic reduction of Li2S4. 2D-Fe0.89V0.11S2 has low Li+ diffusion and decomposition barrier of Li2S, which has potential application value in promoting the Li-S redox chemistry. This work deepens the understanding of the doping strategy and provides theoretical guidance for the design and development of sulfur cathode host to improve the Li-S redox chemistry.

Mesoporous Si-WO3-supported Pt catalysts with high catalytic performance and excellent water resistance for toluene oxidation

Reducing emissions of volatile organic compounds (VOCs) is an integral part of improving the quality of the atmospheric environment. Catalytic oxidation has become an effective means of treating low and medium concentration VOCs exhausts due to its advantages in terms of removal efficiency, energy saving and environmental protection. Due to the unique inherent properties of supported precious metal catalysts, they show good catalytic efficiency in VOCs emission reduction. In this study, the mesoporous Si-WO3 support was first synthesized by the P123-assisted sol-gel method, and the xPt/Si-WO3 catalysts with the actual loadings (x = 0.19, 0.48, and 0.81 wt%) of Pt nanoparticles (NPs) were then obtained, physicochemical properties of these materials were characterized using a variety of techniques, and their catalytic activities and water resistance for the oxidation of toluene were evaluated. The results showed that Pt NPs with an average particle size of 2.3−3.3 nm were highly dispersed on the mesoporous Si-WO3 support, and the 0.81Pt/Si-WO3 sample exhibited the highest catalytic activity for toluene oxidation at a space velocity of 20,000 mL/(g h) (T50% = 167 °C and T90% = 180 °C; specific reaction rate at 160 °C = 8.54 µmol/(gPt s), turnover frequency (TOFPt) at 160 °C = 1.67 × 10−3 s−1, and apparent activation energy = 45 kJ/mol). The good catalytic performance of 0.81Pt/Si-WO3 was associated with its large surface area, well dispersed Pt NPs, high adsorbed oxygen species concentration, large toluene adsorption capacity, and strong interaction between Pt NPs and mesoporous Si-WO3. The 0.81Pt/Si-WO3 sample possessed excellent water resistance, and the introduction of 5 vol% or 10 vol% water vapor to the reaction system enhanced toluene oxidation since part of water vapor participated in the oxidation of toluene. In addition, the toluene oxidation pathway might obey the sequence of (adsorbed toluene + adsorbed oxygen species) → benzyl alcohol → (benzoic acid and benzaldehyde) → maleic anhydride → (carbon dioxide and water).

Self-Healing Conjugated Microporous Polyanilines for Effective and Continuous Catalytic Detoxification of 4-Nitrophenol to 4-Aminophenol.

Detoxification of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) with high efficiency and dynamic performance is challenging for a polymeric catalyst. Herein, a series of conjugated microporous polyanilines (CMPAs), capable of efficiently catalytically reducing 4-NP, were synthesized based on the Buchwald-Hartwig cross-coupling reaction mechanism. By adjusting the types of linkers and the molar ratios of linker to core, CMPAs with different Brunauer-Emmett-Teller (BET) specific surface areas and reduction degrees were obtained and used as the catalysts in reducing 4-NP. The ultrahigh catalytic reduction efficiency (K = 141.32 s-1 g-1, kapp = 0.00353 s-1) was achieved when using CMPA-3-0.7 as the catalyst (prepared with 4,4'-diaminodiphenylamine as the linker and a 0.7:1 molar ratio of linker to core). The catalytic reduction performance exhibited a strong correlation with the reduction degree and BET specific surface area of CMPAs. Furthermore, they also exhibit excellent cycling stability and dynamic performance. The coexistence of a microporous structure and high BET specific surface area endowed CMPAs with an increased number of catalytic active centers. The reversible redox transformation of CMPAs in the presence of NaBH4 and air enabled self-healing (the oxidation units in CMPAs were reduced to reduction units by NaBH4, and the newly generated reduction unit in CMPAs was subsequently oxidized to its original state by the O2 in the air), leading to the reduction reaction of 4-NP proceeded continuously and stably. The aforementioned factors resulted in the high efficiency of CMPAs for reducing 4-NP to 4-AP, enhancing the practical application prospects of CMPAs in the detoxification of 4-NP wastewater.

Carbon sphere doped CdS quantum dots served as a dye degrader and their bactericidal behavior analysed with in silico molecular docking analysis.

We have employed a co-precipitation method to synthesize different concentrations of carbon spheres (CSs) doped with cadmium sulfide (CdS) quantum dots (QDs) for catalytic reduction and antibacterial applications. Various morphological and structural characterization techniques were used to comprehensively analyze the CS effect on CdS QDs. The catalytic reduction efficiency of CS-doped CdS QDs was evaluated using rhodamine B dye. The antibacterial efficacy was also assessed against the pathogenic microorganism Escherichia coli (E. coli), and substantial destruction in the inhibitory zone was measured. Finally, the synthesized CS-doped CdS QDs demonstrated favorable results for catalytic reduction and antibacterial applications. Computational studies verified the suppressive impact of these formed QDs on DNA gyrase and β-lactamase of E. coli.

Microwave-Assisted Fabrication of Pd, Co and Ni Nanoparticles Modified-SiO2; as Catalysts in the Reduction Reaction of Organic Pollutants

Nanomaterials have been used in catalytic degradation of organic pollutants also act as catalysts in for many years. Due to excellent catalytic performances of metal-based nanoparticles, these materials have been used extensively in various hybrid catalyst synthesis. The main subject of this study, heterogeneous catalysis is a low cost and multi-purpose process for many pollutants. Catalytic degradation of organic pollutants such as; 2-Nitrophenol, Quinolin Yellow and Rhodamine B was investigated by using Ni, Co, Pd nanoparticles modified SiO2 based nanomaterials. The co-doping effect on the prepared nanomaterials has been investigated with different characterization methods in terms of structural and morphological features: scanning electron microscopy, UV/Vis absorption spectroscopy, energy-dispersive X-ray spectroscopy and foruier-transform infrared spectroscopy. The highest catalytic reduction efficiencies (97.6% and 97.5%) for 2-nitrophenol and Rhodamine B was obtained by Pd-PEG-AP@SiO2 respectively. The synthesized Co-PEG-AP@SiO2 illustrated higher catalytic reduction efficiency for Quinolin Yellow (70.1%) at the end of 60s. The prepared M-PEG-AP@SiO2 nanomaterial (M: Pd,Co,Ni) can be able to utilized degradation of organic contaminants effectively.

Density Functional Theory Study of CuAg Bimetal Electrocatalyst for CO2RR to Produce CH3OH

Converting superfluous CO2 into value-added chemicals is regarded as a practical approach for alleviating the global warming problem. Powered by renewable electricity, CO2 reduction reactions (CO2RR) have attracted intense interest owing to their favorable efficiency. Metal catalysts exhibit high catalytic efficiency for CO2 reduction. However, the reaction mechanisms have yet to be investigated. In this study, CO2RR to CH3OH catalyzed by CuAg bimetal is theoretically investigated. The configurations and stability of the catalysts and the reaction pathway are studied. The results unveil the mechanisms of the catalysis process and prove the feasibility of CuAg clusters as efficient CO2RR catalysts, serving as guidance for further experimental exploration. This study provides guidance and a reference for future work in the design of mixed-metal catalysts with high CO2RR performance.

Eco-Friendly Method for Wood Aerogel Preparation with Efficient Catalytic Reduction of 4-Nitrophenol.

The advancement of science and technology and the growth of industry have led to an escalating discharge of domestic sewage and industrial wastewater containing dyes. This surge in volume not only incurs higher costs but also exacerbates environmental burdens. However, the benefits of green and reusable catalytic reduction materials within dye processes are still uncertain. Herein, this study utilized the eco-friendly deep eutectic solvent method (DESM) and the chlorite-alkali method (CAM) to prepare a cellulose-composed wood aerogel derived from natural wood for 4-nitrophenol (4-NP) reduction. The life cycle assessment of wood aerogel preparative process showed that the wood aerogel prepared by the one-step DESM method had fewer environmental impacts. The CAM method was used innovatively to make uniform the chemical functional groups of different wood species and various wood maturities. Subsequently, palladium nanoparticles (Pd NPs) were anchored in the skeleton structure of the wood aerogel with the native chemical groups used as a reducing agent to replace external reducing agents, which reduced secondary pollution and prevented the agglomeration of nanoparticles. Results showed that the catalytic reduction efficiency of 4-NP can reach 99.8%, which shows promises for applications in wastewater treatment containing dyes. Moreover, investigation of the advantages of preparation methods of wood aerogel has important implications for helping researchers and producers choose suitable preparation strategies according to demand.

A self-cleaning window for high-efficiency photodegradation of indoor formaldehyde

Formaldehyde (HCHO) as an indoor air pollutant released by new furniture and decorative materials is of great concern. Developing a self-cleaning device to remove HCHO is an ideal way to improve indoor air quality. In this study, a self-cleaning window with a multilayered structure constructed from fluorine-doped tin oxide/bismuth tungstate/resorcinol-formaldehyde resin (FTO/Bi2WO6/RF) has been fabricated, which is capable of degrading HCHO in natural indoor condition. The as-fabricated device could utilize the natural room light and promote the generation and transfer of the photocatalytic carriers in Bi2WO6, which subsequently delivers a good catalytic oxygen reduction efficiency in RF to produce hydrogen peroxide (H2O2). The as-synthesized H2O2 could further split into hydroxyl radicals (•OH), then oxide the HCHO molecules in the air. The present study demonstrates a novel and efficient strategy to fabricate a transparent multifunctional window for self-cleaning indoor gaseous pollutants, the concept is of great importance to be expanded in a broad range of indoor furniture for in-house air pollution control.

Ultra-rapid catalytic reduction of methyl green dye using tetra methyl ammonium bromide derived cobalt nanoparticles

Cobalt nanoparticles (CoNPs) were fabricated from cobalt chloride hexahydrate (CoCl2·6H2O) through a novel aqueous phase reduction protocol using sodium borohydride (NaBH4) as reducer and tetra methyl ammonium bromide (TMAB) as stabilizing reagent. As synthesized CoNPs were characterized via different advanced techniques including scanning electron microscopy (SEM), X-ray diffraction (XRD), atomic force microscopy (AFM), and Fourier transform infra-red (FTIR) spectroscopy. The results depict that as prepared CoNPs were spherical in shape, evenly distributed, crystalline in nature and possessed an average diameter of 10 nm. These CoNPs (1.3 mg) were found to play the role of highly efficient catalysts for ultra-rapid reduction of methyl green (MG) designated as a model dye in one minute of time for 0.1 mM (≈ 45.5 ppm) MG as evident from ultra-violet visible (UV–Vis) spectroscopy. These CoNPs were reused 5 times with 100–94.2 % catalytic efficiency. CoNPs were applied for reduction of MG dye in tap water demonstrated as representative environmental sample with outstanding performance. The application of this catalyst could be extended for rapid reduction of other toxic dyes in several types of aqueous matrices. This study is important because the synthesis of cheaper catalyst like CoNPs is quite easy while its significance is enhanced catalytic reduction efficiency for MG. These findings can be used by our group to solve the issue of environmental contamination especially caused by synthetic dyes like methyl violet, methylene blue, eosin B and so on. We can use the waste water from textile and food industry for this study.

Comparative catalytic reduction and degradation with biodegradable sodium alginate based nanocomposite: Zinc oxide/N-doped carbon nitride/sodium alginate

Sodium alginate (SA) is a biodegradable macromolecule which is used to synthesize nanocomposites and their further use as catalysis. Zinc oxide (ZnO) and nitrogen doped carbon nitride (ND-C3N4) nanoparticles are prepared using solvothermal and hydrothermal methods, respectively. ZnO/ND-C3N4/SA nanocomposites are successfully synthesized by employing in-situ polymerization. The presence of essential functional groups is confirmed by Fourier transform infrared (FTIR) spectroscopic analysis. Controlled spherical morphology for ZnO nanoparticles, with an average diameter of ∼52 nm, is shown by Scanning electron microscopic (SEM) analysis, while rice-like grain structure with an average grain size ∼62 nm is exhibited by ND-C3N4 nanoparticles. The presence of required elements is confirmed by Energy dispersive X-ray spectroscopic (EDX) analysis. The crystalline nature of nanocomposites is verified by X-ray diffraction spectroscopic (XRD) analysis. The investigation of the catalytic efficiency for degradation and reduction of various organic dyes is carried out on nanoparticles and nanocomposites. Thorough examination and comparison of parameters, such as apparent rate constant (kapp), reduction time, percentage reduction, reduced concentration and half-life, are conducted for all substrates. The nanocomposites show greater efficiency than nanoparticles in both reactions: catalytic reduction and catalytic degradation.

Efficient catalytic reduction of dyes by single or agglomerated nano‑silver functionalized wood and hydrodynamic simulation of wood channels

Wood has a multi-scale pore structure, creating conditions for the development of new water purification materials. However, the adsorption capacity of wood for dyes is always limited, so this study combines the unique structure of wood with Ag nanoparticles (NPs) to achieve efficient catalytic reduction of dyes, harnessing the advantages of both. Ag/wood composite filtration materials with different Ag contents were prepared by hydrothermal method and vacuum impregnation. The results showed that with the increase of Ag content, the interaction between metal and wood channels and the degradation performance of Ag/wood composite materials exhibited a volcano-shaped trend. The contact area between Ag NPs and dye molecules plays a key role in the degradation of dye. The load phenomenon and internal flow state were discussed in detail by means of hydrodynamic simulation. Ag0.05/wood composite made silver nanoparticles and dye molecules reach a high balance and reduction degree. Therefore, Ag0.05/wood composites showed the highest catalytic reduction efficiency and great stability during the degradation of dyes, with a degradation efficiency of up to 96.9 %. The novelty of this study lies in the detailed description of the electron transfer process and mechanism of Ag NPs as a relay during MB degradation.

Dual-active-component assembly catalyst based continuous flow system for organic reactions with high processing rate

Designing and fabricating suitable packing catalyst with high activity and low flow resistance for continuous flow system is highly desirable but remains a grand challenge. Here we report a facile one-pot strategy to synthesize a dual-active-component assembly catalyst (DACAC) with N-doped holey graphene (NHG) anchored single-atom Pd (Pd1) self-assembled on fibrous aluminum silicate cluster (FASC) skeleton. The resultant Pd1/NHG–FASC DACAC possesses dual-active-components (i.e., Pd atoms and NHG) and hierarchical architecture and can be easily integrated into a fixed-bed platform to construct a catalytic continuous flow system. This fixed-bed system based on the assembly catalyst architecture effectively drives continuous flow reactions with excellent catalytic efficiency for nitroarene reduction and phenylboronic acid oxidative hydroxylation reactions. The processing rate for catalytic reduction of 4-nitrophenol is 1.5 × 10–3 mmol·mg−1·min−1, which is much higher than that of other previously reported packing catalysts based fixed-bed systems. The activity enhancement strategy of dual-active-component provides a new approach to design highly efficient catalytic materials.

Ultralong hydroxyapatite nanowires-based flow-through reactor with high loading of silver nanoparticles for fast continuous catalytic reduction of organic dyes and disinfection of wastewater

The noble metal nanoparticles (NPs) immobilized flow-through reactors have attracted significant attention for the continuous and efficient purification of wastewater contaminated with organic dyes and microorganisms without the need of subsequent recycling processes. However, achieving both high loading of noble metal NPs and high permeation flux concurrently has been a challenge for most reported flow-through reactors. In this study, inspired by the mussel bio-adhesion strategy, we have employed the tannic acid coating method and successfully synthesized Ag NPs-loaded ultralong hydroxyapatite (HAP) nanowires that exhibited an ultra-high loading amount (21.8 wt%). These nanowires were utilized as building blocks alongside chitosan (CS) to fabricate robust and highly porous flow-through reactors (Ag@HAP/CS) for continuous catalytic reduction of organic dyes and water disinfection. The Ag@HAP/CS reactor demonstrates excellent catalytic reduction efficiency (99.3 %) towards MEB at a high flux (2000 L m−2 h−1) with an extremely low concentration of NaBH4 (MEB:NaBH4 = 1:1). This result is attributed to the high loading of Ag NPs, great structural stability in flowing water, and sufficient length along the flowing direction. The reactor also shows remarkable recyclability through water flushing. Ag@HAP/CS exhibits remarkable water disinfection performance against Escherichia coli and diverse bacteria in natural river water, achieving nearly 100 % disinfecting efficiency. This study provides new insights into the strategy of using nanomaterials as intermediate carriers of noble metal nanoparticles to fabricate 3D flow-through reactors, which enable fast and continuous purification of wastewater with ultra-high catalytic efficiency and antimicrobial performance.

Optimization of the Uniformity Index Performance in the Selective Catalytic Reduction System Using a Metamodel

The significance of the selective catalytic reduction system in vehicles increases in line with the high standards of emission control and enhanced selective catalytic reduction efficiency. This study aims to improve the performance of the selective catalytic reduction system through an optimization method using a metamodel. The objective function is defined as the ammonia uniformity index, and the design parameters are defined in relation to the pipe length and mixer related to the chemical reaction of the urea solution. The range of design parameters has been designated by a trial-and-error method in order to maintain the overall design drawings of the selective catalytic reduction system and prevent modeling errors. Three algorithms, namely, ensemble decision tree, Kriging, and radial basis function, are employed to develop the metamodel. The accuracy of the metamodel is verified based on three indicators: the normalized root mean square error, root mean square error, and maximum absolute error. The metamodel is generated using the Kriging model, which has the highest accuracy among the algorithms, and optimization is also performed. The predicted optimization results are confirmed by computational fluid dynamics numerical analysis with a 99.83% match. The ammonia uniformity index is improved by 1.38% compared to the base model, and it can be said that the NOx purification efficiency is improved by 30.95%. Consequently, optimizing the uniformity index performance through structural optimization is of utmost importance. Furthermore, this study reveals that the design variables related to the mixer play a crucial role in the performance. Therefore, using the metamodel to optimize the selectively catalytic reduction system’s structure should be considered significant. Finally, in the future, the analysis model can be validated using test equipment based on the findings of this study.

Efficient asymmetric synthesis of ethyl (R)-3-hydroxybutyrate by recombinant Escherichia coli cells under high substrate loading using eco-friendly ionic liquids as cosolvent.

Ionic liquids (ILs) which synthesized from bio-renewable materials have recently attracted much attention for their applications in biocatalysis. Ethyl (R)-3-hydroxybutyrate ((R)-EHB) as a versatile chiral intermediate is of great interest in pharmaceutical synthesis. This study focuses on evaluating the performances of choline chloride (ChCl)-based and tetramethylammonium (TMA)-based neoteric ILs in the efficient synthesis of (R)-EHB via the bioreduction of ethyl acetoacetate (EAA) at high substrate loading by recombinant Escherichia coli cells. It was found that choline chloride/glutathione (ChCl/GSH, molar ratio 1:1) and tetramethylammonium/cysteine ([TMA][Cys], molar ratio 1:1) as eco-friendly ILs not only enhanced the solubility of water-insoluble EAA in the aqueous buffer system, but also appropriately improved the membrane permeability of recombinant E. coli cells, thus boosting catalytic reduction efficiency of EAA to (R)-EHB. In the developed ChCl/GSH- or [TMA][Cys]-buffer systems, the space-time yields of (R)-EHB achieved 754.9g/L/d and 726.3g/L/d, respectively, which are much higher than neat aqueous buffer system (537.2g/L/d space-time yield). Meanwhile, positive results have also been demonstrated in the bioreduction of other prochiral ketones in the established IL-buffer systems. This work exhibits an efficient bioprocess for (R)-EHB synthesis under 325g/L (2.5M) substrate loading, and provides promising ChCl/GSH- and [TMA][Cys]-buffer systems employed in the biocatalysis for hydrophobic substrate.

Enhanced artificial nitrogen fixation efficiency induced by construction of ternary TiO2/MIL-88A(Fe)/g-C3N4 Z-scheme heterojunction

Herein, a ternary TiO2/MIL-88A(Fe)/g-C3N4 heterojunction is successfully constructed through a facile hydrothermal strategy for enhancing solar energy harvesting and efficiency of catalytic nitrogen reduction induced by enlarged light absorption range, increasing interfacial charge transfer ability and desirable stability. Under the simulated sunlight irradiation, the N2 fixation experiment shows that the yield of NH3 reaches 1084.31 μmol/(g·h) over the TiO2/MIL-88A(Fe)/g-C3N4 photocatalyst, and the yield is significantly enhanced, which is 33.68 and 13.94 times that is higher than the pure TiO2 and g-C3N4, respectively. In a mean time, the excellent performance of the photocatalytic N2 fixation over the ternary TiO2/MIL-88A(Fe)/g-C3N4 is verified based on density function theory calculation and the decisive step over the composite is investigated by calculating Gibbs free energies of nitrogen reduction paths. The performance enhancement mechanism of TiO2/MIL-88A(Fe)/g-C3N4 is speculated, which indicates that the hybridized three-component system presents a desirable Z-scheme band alignment, resulting in the improvement of separation and transfer efficiency of photoinduced charge carriers. The article shows a new and high-efficiency TiO2/MIL-88A(Fe)/g-C3N4 photocatalysis for excellent nitrogen reduction ability.

Preparation of Cu2ZnSnS4@TiO2 nanotubes by pulsed electrodeposition for efficiently photoelectrocatalytic reduction of CO2 to ethanol

In this work, we reported a method of preparing Cu2ZnSnS4@TiO2 nanotubes (Cu2ZnSnS4/TiO2NTs) composite electrode by pulse electrodeposition and high-temperature vulcanization, which possesses high catalytic conversion efficiency for CO2 reduction and stable performance. In addition, the influence of pulse parameters on the morphology and photoelectrochemical properties of Cu2ZnSnS4/TiO2NTs composite electrode were studied in detail. The band gap of Cu2ZnSnS4/TiO2NTs is 1.39 eV, which is significantly reduced compared with TiO2NTs (3.27 eV). There are differences in the morphology, catalytic efficiency and product selectivity of the catalytic interface constructed by different pulse electrodeposition parameters. The photoresponse current of the composite electrode prepared by optimizing the parameters reaches −7 μA cm−2, and the ethanol yield is 7.0 μmol cm−2 after 5 h of photoelectrocatalytic reduction of CO2. No new phase was generated and the photocurrent density remained 33.2% of the original after the catalytic process, which indicated the Cu2ZnSnS4/TiO2NTs possess stable catalytic performance.

Synthesis of mesoporous Ag/α-Fe2O3/TiO2 heterostructures with enhanced and accelerated photo/-catalytic reduction of 4-nitrophenol.

4-Nitrophenol (4-NP) is reported to originate disadvantageous effects on the human body collected from industrial pollutants; therefore, the detoxification of 4-NP in aqueous contamination is strongly recommended. In this study, the heterojunction mesoporous α-Fe2O3/TiO2 modulated with diverse Ag percentages has been constructed via a sol-gel route in the occurrence of a soft template P123. The formation of biphasic crystalline TiO2 anatase and brookite phases has been successfully achieved with the average 10nm particle sizes. The photo/-catalytic reduction of 4-NP has been performed utilizing NaBH4 as a reducing agent with and without visible illumination. All Ag/Fe2O3/TiO2 nanocomposites exhibited significantly higher photo/-catalytic reduction efficiency than pure Fe2O3, TiO2 NPs, and Fe2O3/TiO2 nanocomposite. 2.5% Ag/Fe2O3/TiO2 nanocomposite was considered the highest and superior photocatalytic reduction efficiency, and it almost achieved 98% after 9min. Interestingly, the photocatalytic reduction of 4-NP was accelerated 9 times higher than the catalytic reduction over 2.5% Ag/Fe2O3/TiO2; its rate constant value was 709 and 706 times larger than pure TiO2 and Fe2O3 NPs, respectively. The enhanced photocatalytic reduction ability of Ag/Fe2O3/TiO2 nanocomposite might be referred to as significantly providing visible light absorption and a large surface area, and it can upgrade the effective separation and mobility of electron holes. The stability of the synthesized catalysts exhibited that the obtained catalysts can undergo a slight decrease in reduction efficiency after five successive cycles. This approach highlights a novel route for constructing ternary nanocomposite systems with high photo/-catalytic ability.

In Situ Implantation of Bi2S3 Nanorods into Porous Quasi-Bi-MOF Architectures: Enabling Synergistic Dissociation of Borohydride for an Efficient and Fast Catalytic Reduction of 4-Nitrophenol.

Catalytic hydrogenation reduction based on sodium borohydride (NaBH4) has gained attention as an appealing "one-stone-two-birds" approach for the simultaneous elimination of nitroaromatic pollutants and the production of high-value aminoaromatics under mild conditions. However, the slow kinetics of NaBH4 dissociation on the surface of catalysts restrict the catalytic hydrogenation reduction efficiency. Herein, we report an intelligent localized sulfidation strategy for an in situ implantation of Bi2S3 nanorods within quasi-Bi-MOF architectures (Bi2S3@quasi-Bi-MOF) by fine-tuning the pyrolysis temperature. In this novel Bi2S3@quasi-Bi-MOF, the porous quasi-Bi-MOF enables efficient adsorption of BH4- and 4-nitrophenol (4-NP), while Bi2S3 facilitates the BH4- dissociation to form Hads* species adsorbed on the catalyst surface. Benefiting from the synergistic structure, Bi2S3@quasi-Bi-MOF exhibits excellent performance for the catalytic reduction of 4-NP, delivering a high turnover frequency (TOF) of 1.67 × 10-4 mmol mg-1 min-1 and an extremely high normalized rate constant (knor) of 435298 s-1 g-1. The kinetic analysis and electrochemical tests indicate that this catalytic hydrogenation reduction follows the Langmuir-Hinshelwood mechanism. This study enriches the synthetic strategy of MOF-based derivatives and offers a new catalytic platform for hydrogenation reduction reactions.

Surfactant‐Enhanced Nano Spinel Oxide for Applications in Catalysis, Dye Degradation and Antibacterial Activity

AbstractNovel surfactant supported Mn−Co−Ni oxide was effectively synthesized by simple and economic co‐precipitation method to investigate the efficiency of catalytic reduction of 4‐nitrophenol, degradation of methylene blue and antibacterial properties. The optical, structural and chemical compositions were cautiously analyzed by X‐ray diffraction (XRD), Field emission scanning electron microscopy (FESEM), X‐ray photoelectron microscopy (XPS), ultraviolet‐visible (UV‐Vis), Fourier transform infrared (FT‐IR), Brunauer‐Emmett‐Teller (BET) and dynamic light scattering (DLS) analyses. XRD analysis showed cubic structure with average crystallite size of 19–21 nm. FESEM images confirmed the combination of spherical, needle, plate and rod like shapes. Accordingly, a high specific surface area of 55.66 m2 g−1 was achieved by urea/Mn−Co−Ni oxide. Band gap of ternary metal oxide was found in the range of 3.4‐3.6 eV. The XPS analysis confirmed the presence of manganese, cobalt and nickel as major parts with a 2p core level region. The M−O bond formation was confirmed by the peak appeared in the range of 500–600 cm−1. The negative charge of ternary metal oxide was confirmed by negative zeta potential value. The reduction of 4‐nitrophenol was carried out by Mn−Co−Ni oxide with the efficiency of >99 % and the degradation efficiency against methylene blue was studied. The synthesized catalyst was potent against S. aureus at higher concentration.