Catalytic Potential Research Articles

‘Positive disruption’: catalysing system-wide work on health inequalities through embedded research

Abstract Background This presentation explores embedded research as an innovative model for bridging system-level knowledge to action gaps in public health. Embedded researchers (ERers) are university-employed researchers co-located in public health organisations, who work to boost capacity in these organisations to tackle inequalities by better use of evidence in decision-making, evaluation and service improvement Methods Drawing on the initial phase of the role and wider literature, we qualitatively reflect on strengths and limits of a system-level ERer model. Most ERer evidence draws on a one-to-one organisational model. This presentation explores a different model of an ERer embedded in and working across a public health system (health services, municipality, third sector) in a large city in north England Results Our focus is on catalytic features of the ERer role (1) positionality: being embedded at system-level gives fuller understanding of inter-organisational connections and of the implications of emergent system changes; (2) convening: bringing together partners improves mutual awareness and builds interest in collectively pursuing research aligned to identified population health needs and public health priorities in the city; (3) co-production to build capacity: working with a new cross-organisational partnership to collectively address issues constraining opportunities to pursue system-level research; working with the municipality to explore the production/use of research to inform decisions on approaches towards health inequalities. This includes work on links between public health and other functions focused on social determinants of health Conclusions This presentation outlines distinctive consequences of system-level embedded research in a city-wide public health system. It critically appraises the transferability of this model of knowledge production and mobilisation at the intersection of system and cross-organisational action on health inequalities. Key messages • System-level embedded research is an innovative model for helping to bridge system-level knowledge to action gaps in public health. • The model has catalytic benefits and transferability potential, although this needs to be considered in relation to the specific context for proposed system-level embedded research.

Host-guest-induced electronic state triggers two-electron oxygen reduction electrocatalysis

Supramolecular polymers possess great potential in catalysis owing to their distinctive molecular recognition and dynamic crosslinking features. However, investigating supramolecular electrocatalysts with high efficiency in oxygen reduction reaction to hydrogen peroxide (ORHP) remains an unexplored frontier. Herein, we present organic polymers for ORHP by introducing cyclodextrin-containing noncovalent building blocks, affording these supramolecules with abundant dynamic bonds. The electronic states and reaction kinetics are further well-modulated via a host-guest strategy, resulting in appropriate regional electron binding force and controllable chemical activity. Notably, integrating supramolecular units into phenyl group-containing model covalent polymer achieves a production rate of 9.14 mol g−1cat h−1, with 98.01% Faraday efficiency, surpassing most reported metal-free electrocatalysts. Moreover, the dynamic bonds in supramolecular catalysts can effectively regulate the binding ability of oxygen intermediates, leading to high reactivity and selectivity for the 2e− pathway. Supported by theory calculation and in situ experiment, C atoms (site–1) adjacent to the –C = N (N) group are potential active sites. This work pioneers host-guest strategy and provides inspiring ideas for the ORHP process.

Enzymatic Glycosylation of 4′-Hydroxychalcones: Expanding the Scope of Nature’s Catalytic Potential

Chalcones, including 4′-hydroxychalcones, have garnered significant attention in the area of drug discovery due to their diverse pharmacological properties, such as anti-inflammatory, antioxidative, and anticancer effects. However, their low water solubility and bioavailability limit their efficacy in vivo. Glycosylation presents a promising approach to enhance the water solubility, stability, and metabolic properties of chalcones. This study investigates the enzymatic glycosylation of eight chemically synthesized 4′-hydroxychalcones using a diverse set of sugar glucosyltransferases from bacterial, plant, and fungal sources, alongside Glycine max sucrose synthase (GmSuSy) in a cascade reaction. Among the tested enzymes, five exhibited a remarkable versatility for glycoside production, and for large-scale biotransformation, flavonoid 7-O-glucosyltransferase Sbaic7OGT from Scutellaria baicalensis was selected as the most effective. As a result of the experiments conducted, eight trans-chalcone glycosides were obtained. During the purification of the reaction products, we also observed the isomerization of the products by simple sunlight exposure, which resulted in eight additional cis-chalcone glycosides. This study highlights the novel use of a cascade reaction involving Glycine max sucrose synthase (GmSuSy) for the efficient glycosylation of trans-4′-hydroxychalcones, alongside the unexpected discovery of cis-chalcone glycosides during the purification process.

Atomically Precise Ternary Cluster: Polyoxometalate Cluster Sandwiched by Gold Clusters Protected by N‐Heterocyclic Carbenes

AbstractCoinage metal (Au, Ag, Cu) cluster and polyoxometalate (POM) cluster represent two types of subnanometer “artificial atoms” with significant potential in catalysis, sensing, and nanomedicine. While composite clusters combining Ag/Cu clusters with POM have achieved considerable success, the assembly of gold clusters with POM is still lagging. Herein, we first designedly synthesized two cluster structural units: an Au3O cluster stabilized by diverse N‐heterocyclic carbene (NHC) ligands and an amine‐terminated POM linker. The subsequent reaction involved amine substitution in the POM linker for the central O atom in the Au3O cluster, resulting in the first ternary composite cluster—a POM cluster sandwiched by two Au clusters protected by NHCs. Single‐crystal X‐ray diffraction and other characteristic methods characterized their atomically precise structures. Furthermore, altering the NHC ligands decreased the number of gold atoms in the sandwich structures, accompanying the different protonated degrees of amine ligand in the terminal end of the POM linker. These composite clusters showed excellent performances in catalytic H2O2 conversion through the synergistic effect between gold clusters and POM clusters. This work opens a new avenue to functional composite metal clusters and would promote their enhanced catalysis applications through intercluster synergistic interactions within composite systems.

A‐site Regulated (PrBa)xCo1.5Fe0.5O6‐δ Double Perovskite Oxides: Highly Active and Durable Electrocatalysts for the Enhanced Oxygen Evolution Reaction

Oxygen evolution reaction (OER) represents a significant bottleneck in many energy technologies such as electrochemical water splitting, metal‐oxygen (O) batteries, and solid oxide fuel cells (SOFCs), because of the complexity of the reaction process. Double perovskite oxides (ABO3), recognized for their compositional flexibility, have emerged as excellent OER activity and stability. This study investigates the catalytic potential of B‐site ordered double ABO3 with (PrBa)xCo1.5Fe0.5O6‐δ (PBCF‐x, x=0.9‐1.1) in alkaline media. The results reveal that PBCF‐0.9, characterized by an A‐site deficient composition, exhibits exceptional OER activity. It demonstrates a low Tafel slope of 76.12 mV⋅dec‐1 and a low overpotential (η) of 270 mV at 10 mA⋅cm‐2. Notably, the intrinsic OER activity of PBCF‐0.9 is 25% higher than that of the stoichiometric PBCF‐1.0. Additionally, PBCF‐0.9 exhibits remarkable durability, as evidenced by its stable performance during a 6‐hour chronopotentiometry (CP) test and minimal microstructural changes. These results underscore the effectiveness of A‐site deficiency in optimizing the structure of double ABO3 for improved OER performance. This approach presents a promising strategy for designing highly efficient, stable, and inexpensive catalysts for energy‐related applications.

Synthesis and Characterization of a Hercynite-Supported Copper(II) Complex Based on 1,10-Phenanthroline-5,6-dione and Acetylacetone Building Blocks and Its Catalytic Application in Annulation Reactions.

In the present work, a novel Cu(II) complex containing 10-phenanthroline-5,6-dione (phen-dione) and acetylacetone (acac) was prepared via solid-phase synthesis on silica-modified hercynite magnetic nanoparticles (MNPs). The resulting structure underwent thorough structural analysis using diverse instrumental techniques. The catalytic potential of the synthesized Cu(II) complex was successfully demonstrated in the synthesis of 2-amino-3-cyano-4H-chromenes. This was accomplished via a one-pot, three-component condensation reaction involving lawsone, malononitrile, and aromatic aldehydes in ethanol under reflux conditions, leading to remarkably high yields and product purity. Several advantages stem from this investigation. Notably, the use of ethanol as a sustainable and environmentally friendly solvent highlights the ecoconscious approach of this research. Moreover, the reaction conditions were mild and the separation process was straightforward, resulting in reduced byproducts as well as time and cost savings. Furthermore, the catalyst's stability and reusability were studied under optimal conditions, revealing excellent reversibility for up to five cycles without any significant loss of activity. This excellent performance underscores the potential of the Cu(II) complex for sustainable catalytic applications.

Synergistic Coordination Effect and Metal-Support Interaction Engineering of Single-Atom Mn-N2 Sites for Boosting Sensitive and Selective Dopamine Biosensing in Human Serum.

Coordination environment of metal atoms is core for designing high-performance single-atom catalysts (SACs), while metal-support interaction also has an important effect on structure-function relationship. Nevertheless, the interaction effect of metal-support is mostly ignored. Through synergistic regulation of coordination environment and metal-support interaction, Mn SAC with atom-dispersed Mn-N2 sites on dopamine (DA) support is synthesized for sensitive and selective DA oxidation based on theoretical calculations and experimental explorations. MnN2 presents the more optimal catalytic site for DA oxidation than other coordination conditions, enhancing sensitivity including a wide range, a low limit of detection, and particularly a very low catalytic potential. The construction of Mn-N2 active sites on DA carbon promotes the coupling between Mn metal atoms and DA support, decreasing work function, facilitating electron exchange, shortening response time, and boosting selectivity. Both the catalytic mechanism of Mn SAC toward DA and the relation construction of catalyst's structure and catalytic function are established.

Sparkling Synergy: Enhancing Hydrogen Evolution with a Mesoporous CoP/FeP Interface.

The reaction kinetics is predominantly determined by the surface and interface engineering of electrocatalysts. Herein, we demonstrate the growth of cobalt monophosphide and iron monophosphide (CoP/FeP) with an effective solid interface. The surface of CoP/FeP is mesoporous, which is obtained by phosphidizing mesoporous CoFe2O4. The CoP/FeP electrode exhibits substantially superior hydrogen evolution reaction (HER) performance compared to CoP and FeP. The overpotentials (η) required to generate 10 mA cm-2 are determined to be around 98 mVRHE (CoP/FeP), 220 mVRHE (FeP), and 265 mVRHE (CoP) in an acidic electrolyte. The exchange current density and Tafel slopes suggest that CoP/FeP has better redox properties and kinetic abilities compared to FeP and CoP. Furthermore, the CoP/FeP electrode exhibits reduced electrochemical impedance and superior surface charge transport characteristics in comparison to both the CoP and FeP electrodes. In addition to having a greater number of catalytically active sites, the turnover frequency of CoP/FeP is approximately 2 and 5 times higher than that of FeP and CoP, respectively. The CoP/FeP electrode maintains a consistent current density of around 25 mA cm-2 for a continuous period of 24 h during the HER, attesting to the excellent durability of the CoP/FeP electrode. In addition, a relationship between differential hydrogen adsorption energy (ΔEH), the corresponding Gibbs free energy change (ΔGH), and the hydrogen coverage on distinct surfaces, namely, CoP, FeP, and CoP/FeP, is established. The calculation findings show that the CoP/FeP surface, which is predominantly exposed with CoP, exhibits the highest catalytic potential for the HER. The estimation of the specific HER activity of the electrodes, normalized to the electrochemically active surface area, corroborates the calculation findings.

Functionalization of Graphene Oxide with Guanidine: Synthesis, Characterization and Catalytic Potential in Aldol and Knoevenagel Condensation Reactions

AbstractHerein, we synthesized guanidine functionalized graphene oxide nanocomposites referred to GO‐GN NCs using hummer's method. GO‐GN NCs was characterized using Fourier‐Transform Infrared Spectroscopy, Powder X‐ray Diffraction, Thermogravimetric Analysis, Raman Spectroscopy, Field Emission Scanning Electron Microscopy, Transmission Electron Microscopy, Brunauer‐Emmett‐Teller (BET) surface area analysis to confirm successful formation of GO‐GN NCs catalysts. The catalytic performance for GO‐GN NCs was evaluated for Knoevenagel and Aldol condensation reaction in aqueous medium at ambient condition and result shows that it could be used as a highly efficient, stable, and durable catalyst. In addition, it has another feature such as easy workup procedure, large substrate tolerance, high reaction yield, good recyclability, and environmental friendliness.

Green biosynthesis of silver nanoparticles using leaf extract of Ammannia baccifera for evaluating their antioxidant, antibacterial and catalytic potentials

The objective of this work is to create an easy, economical, and environmentally sustainable process for making silver nanoparticles (AB-AgNPs) by employing Ammannia baccifera leaf extract as a provider of reducing agents. A surface plasmon resonance (SPR) peak was observed at 413 nm in the UV–Vis absorption spectrum of AB-AgNPs, and it ensured the formation of nanoparticles. The unique bands in FTIR revealed the participation of phytochemicals with effective functional groups in the reduction and stabilization of AB-AgNPs. SEM revealed almost spherical-shaped AB-AgNPs, while EDX confirmed the presence of metallic silver with a strong signal at 3 eV. TEM further verified the formation of spherically-shaped AB-AgNPs, which ranged in size from 13 to 60 nm. The face-centered cubic (FCC) crystal structure of AB-AgNPs was confirmed by an XRD study. TGA, DLS, and Zeta potential studies also assured the stability and particle size distribution of AB-AgNPs. The DPPH and ABTS radicals were used to investigate the antioxidant activity of plant extract and AB-AgNPs, where the best performance of AB-AgNPs was observed in scavenging the ABTS radical with an EC50 value of 27.52 μg/mL. The green-produced AB-AgNPs showed strong catalytic activity for the breakdown of organic dyes (methylene blue, rhodamine B, and para-nitrophenol), and complete dye degradation was attained for each dye within 20 min. AB-AgNPs also showed efficient activity against Escherichia coli in antibacterial tests. These findings suggest that silver nanoparticles (AB-AgNPs) produced from the extract of Ammannia baccifera leaves, may find use in medicinal and environmental contexts.

Effect of Al doping on the structural, optical and photocatalytic properties of sol-gel spin-coated NiO thin films

Nanostructured NiO thin films are renowned for their catalytic activity and potential for degradation of industrial effluents. In this study, Al-doped NiO (Ni1-xAlxO with x = 0, 0.02, 0.04, 0.06, and 0.08) thin films were synthesized by sol–gel spin coating, and the influence of Al doping on their physical properties, surface morphology, optical band gap, and photo-catalytic performance was investigated. X-ray diffraction (XRD) analysis confirmed the high crystallinity of the thin films and revealed a pronounced doping effect on parameters such as crystallite size, microstrain, and dislocation density. Scanning electron microscopy (SEM) revealed the formation of spherical nanoparticles with particle sizes ranging from 26 nm to 11 nm. The elemental composition was verified through energy-dispersive x-ray (EDX) analysis. The optical bandgap of the prepared films was determined through UV-visible spectroscopy. The Ni0.98Al0.02O films exhibited the lowest PL intensity, indicating a reduced recombination rate. To assess the photo-degradation capability of the prepared thin film catalysts, industrial effluent Indigo Carmine was employed as a test compound. The Ni0.98Al0.02O sample demonstrated the highest degradation efficiency, achieving about 96% degradation within 2 h of UV–vis light irradiation. Furthermore, the degradation followed pseudo-first-order kinetics.

Enhanced Hydrogen Evolution Reaction Activity through Bimetallic Phosphide Integration in ReS2/Re2O7 Heterostructure

AbstractDeveloping a nonprecious and sustainable electrocatalyst in clean energy generation is quite noteworthy. Transition metal chalcogenides, oxides, and phosphides have emerged as promising candidates to substitute Pt‐based catalysts. In this study, we explore the catalytic potential of ReS2, a promising member of the transition metal dichalcogenides (TMD) family, for hydrogen evolution reactions (HER). The formation of rhenium oxide during the synthesis of ReS2 and further incorporation of a bimetallic phosphide NiCuP in a sequential hydrothermal synthesis reveals an excellent HER activity, as demonstrated by photoelectrochemical and electrochemical studies. Notably, the catalyst exhibits a significantly lower overpotential of −0.10 V (corresponding to −10 mA/cm2) and achieves a high current density of approx. −271 mA/cm2 at −0.79 V versus reversible hydrogen electrode (RHE) under light irradiation. The catalyst demonstrates high stability. These findings underscore the potential of NiCuP‐integrated ReS2/Re2O7 as a highly efficient and sustainable catalyst for HER.

Exploring the catalytic potential of watermelon urease: Purification, biochemical characterization, and heavy metal precipitation

Bioactive urease from watermelon (Citrullus lanatus) seeds was purified using acetone fractionation, anion-exchange, and size-exclusion chromatography, achieving a 121-fold increase and specific activity of 3216 U/mg. The enzyme appeared as a single band on native and SDS-PAGE, with a molecular mass of 480 ± 10 kDa and subunit mass of 80 ± 10 kDa, indicating six identical subunits. Atomic absorption spectroscopy revealed 1.46 nickel ions per subunit. Watermelon urease exhibited serological similarities with jack bean and pigeon pea ureases, an optimal pH of 7.3, an activation energy of 3 kcal/mol, Vmax of 3571 μmol/min/mg, and Km of 0.16 mM. The enzyme displayed biphasic thermal and pH inactivation kinetics, a strong preference for urea, and a half-life of 70 days with 1 mM DTT. This study highlights watermelon urease's role in bioremediation by facilitating the precipitation of heavy metals as stable carbonates, promoting environmental sustainability.

Unveiling Heterogeneous Catalytic Potential of Distinctly Coordinated Polymers Toward Henry and Morita‐Baylis‐Hillman Reactions

AbstractThree 1D coordination polymers (CPs), {[CuL2(H2O)] ⋅ (H2O)3}n (1) {[CoL2(H2O)2] ⋅ (H2O)}n (2) and {[NiL2(H2O)] ⋅ (H2O)3}n (3), (L1=N‐nicotinoylglycinato) have been synthesized by adopting a solvothermal reaction strategy and characterized through several spectral techniques i. e., elemental analyses, FT‐IR, TGA, EDX, DSC, AAS, and PXRD. X‐ray single crystal analysis revealed the 5‐, 6‐ and 7‐coordinated structures respectively for CPs 1, 2 and 3 wherein, L1 connects the metal ions in a bridging mode. The CPs entail H‐bonding, π–π stacking along with other non‐covalent interactions and expand into 3D supramolecular networks. Further, FESEM and HRTEM provided morphological insight for 1–3 and aid in obtaining interplanar spacings. CPs 1–3 possessing distinct coordination numbers and good thermal stability have been subjected to catalysis after optimization and notably, these serve as efficient, easy to work up, and reusable porous heterogeneous catalysts for Henry and Morita‐Baylis‐Hillman (MBH) reactions with reasonably good yields (97–93 %). Remarkably, catalyzed by 1–3 can be reused at least seven times for the Henry reaction and six times for the MBH reaction, retaining their catalytic efficiency. Relative catalytic efficacy toward the Henry and MBH reactions follows the order 1>2>3. Present findings are based on a rational approach of varying coordination number (5, 6 and 7) and metal ions [Cu(II), Co(II) and Ni(II)] respectively in 1–3 having structural evidence and examine their catalytic performances for typical Henry and MBH reactions.

Synergistic Catalysis of Cobalt Single Atoms and Clusters Loaded on Carbon Film: Enhancing Peroxymonosulfate Activation for Degradation of Norfloxacin

AbstractMany existing research focuses on the differences or performance comparisons between single‐atom or small‐sized nanocluster catalysts, but there is a lack of comprehensive research on the coupling relationship between the structure and activity and the mechanism of synergy. This study investigates the combined catalytic potential of cobalt single atoms (SAs) and nanoclusters (NCs) for enhanced peroxymonosulfate (PMS) activation to degrade norfloxacin (NFX). A novel CoSAs‐NCs/CN/TiO2 catalyst is synthesized, featuring cobalt SAs and NCs uniformly dispersed on the carbon film wrapping TiO2, and the degradation efficiency of the NFX solution is almost completely degraded, with a mineralization rate of 76.35%. Density functional theory (DFT) calculations indicate that the synergistic interaction between cobalt SAs and NCs promotes more efficient PMS adsorption and activation and significantly reduces the activation energy barrier, which enhances electron transfer and increases reactive oxygen species (ROS) generation. This research highlights the robust and versatile nature of this novel catalyst system in addressing various contaminants. This study elucidates the activation mechanism of catalysts, providing new ideas for advanced oxidation processes (AOPs) in environmental remediation, linking the structure and performance of catalysts, and emphasizes the practicality and importance of the CoSAs‐NCs/CN/TiO2 catalyst in effectively and long‐term remediation of water pollutants.

Synthesis of uniform-sized spherical monodisperse K2Ba[Ni(NO2)6] via polymer-assisted anti-solvent crystallization method for the enhanced catalytic pyrolysis of HNIW

Nitro complexes (NCs) have been selected as combustion catalysts for propellants due to their synergistic behavior. However, NCs prepared by traditional methods suffer from poor dispersion and irregular shape, which limit their catalytic potential. Hence, a polymer-assisted anti-solvent crystallization (PAASC) strategy was developed to fabricate potassium barium hexanitronickelate (K2Ba[Ni(NO2)6], PBHNN) crystals. In this method, emulsion particles created by mixing the solvent with the poor solvent serve as spherical templates. The particle size and monodispersity of PBHNN are controlled by PVP content. With 0.042 mol/L PVP, PBHNN were monodisperse with a particle size of 1.05±0.03 μm, which showed the best catalytic behavior for increasing the exothermic amount of hexanitrohexaazaisowurtzitane (HNIW) by 100.6 %. The high catalytic performance is due to the large specific surface area and improved contact efficiency. The in-situ TG-FTIR-MS test revealed that the procedure of PBHNN enhanced the pyrolysis of HNIW. The N-NO2 bonds of HNIW are weakened by the strong attraction of metal oxides to electrons, which accelerates the formation of NO2. Consequently, increased NO2 promotes subsequent oxidation reactions and improves the pyrolysis efficiency of individual HNIW. Therefore, the PAASC method is crucial for the fabrication of spherical monodisperse NCs with uniform particle size and high catalytic activity.

Synthesis of Amorphous and Various Phase-Pure Nanoparticles of Nickel Phosphide with Uniform Sizes via a Trioctylphosphine-Mediated Pathway.

Nickel phosphides are of particular interest because they are highly active and stable catalysts for petroleum/biorefinery and hydrogen production. Despite their significant catalytic potential, synthesizing various phase-pure nickel phosphide nanoparticles of uniform size remains a challenge. In this work, we develop a robust trioctylphosphine (TOP)-mediated route to make highly uniform phase-pure Ni12P5, Ni2P, and Ni5P4 nanoparticles. The synthetic route forms amorphous Ni70P30 nanoparticle intermediates. The reactions can be stopped at the amorphous stage when amorphous particles are desired. The amount of P incorporation can be controlled by varying the ratio of TOP to Ni(II). The mechanism for composition control involves the competition of the kinetics of two processes: the addition of the reduced Ni and the incorporation of P into Ni. Uniform Ni70P30 amorphous nanoparticles can be generated at a high TOP-to-Ni(II) ratio, where the P incorporation kinetics is made to dominate. Ni70P30 can later be transformed into phase-pure Ni12P5, Ni2P, and Ni5P4 nanocrystals of uniform size. The transformation can be controlled precisely by modulating the temperature. A UV-vis study coupled with theoretical modeling reveals Ni(0)-TOPx complexes along the synthetic path. This approach may be expanded to create other metal compounds, potentially enabling the synthesis of uniform nanoparticles of a greater variety.

First-principles investigation of methane to methanol conversion on Ti2CO2 MXene supported single-atom catalyst

Developing efficient catalysts for the conversion of methane (CH4) to methanol (CH3OH) remains a critical challenge in the chemical industry, with significant implications for both energy production and environmental sustainability. This study pioneers the exploration of the Sc/Ti-Ti2CO2 single-atom catalysts (SACs) for this transformation, utilizing density functional theory (DFT) calculations. Notably, our findings reveal that Sc and Ti are uniquely stable on the Ti2CO2 MXene surface, a discovery that could inform future catalyst designs. We also demonstrate that while CH4 weakly physisorbs on the Sc/Ti-Ti2CO2 surface, N2O molecules decompose directly into N2 and highly reactive O* species, which bind with Sc/Ti to drive the catalytic process. The oxidation of CH4 proceeds in two steps: CH4 + O* → CH3* + OH* with reaction barriers of 0.58 eV (Sc) and 1.38 eV (Ti), followed by CH3* + OH* → CH3OH with barriers of 1.5 eV (Sc) and 1.61 eV (Ti). Importantly, the low desorption energy of CH3OH, especially on Sc (0.85 eV), highlights the exceptional catalytic potential of Sc/Ti2CO2 for the direct conversion of CH4 to CH3OH. These results not only underscore the feasibility of using MXene-based SACs for CH4 oxidation but also provide a theoretical foundation for the development of highly efficient catalysts in this domain.

Sustainable synthesis of multifaceted copper oxide nanoparticles from Euphorbia tirucalli: Unveiling antimicrobial and catalytic potential

This work presents Euphorbia tirucalli mediated green synthesis of multi-purpose copper oxide nanoparticles (ET@CuO-NPs) exhibiting enhanced antimicrobial activity. These plant extract capped nanoparticles were characterized using sophisticated techniques such as FTIR, Raman, UV–Vis, SEM, HR-TEM, DLS, zeta potential, XPS and XRD. A uniform rod-shaped morphology was observed in HR-TEM images with size around 50 nm. Antibacterial and antifungal activity was investigated by agar well diffusion method. The bactericidal action was confirmed by zone of inhibition of 28 mm and 34 mm respectively against gram-negative and a gram-positive bacterium. The nanoparticles also show excellent antioxidant activity via free radical scavenging by DPPH. The scope of ET@CuO-NPs was extended to catalytic reduction of nitroaromatic compounds into their corresponding amino derivatives. The reduction of 4-nitrophenol, a model nitroaromatic pollutant could be completed within just 6 min with a recycling efficiency of 8 cycles. Thus, the multifaceted ET@CuO-NPs exhibited diverse therapeutic and catalytic potential.

Promoting Electricity Production and Cr (VI) Removal Using a Light–Rutile–Biochar Cathode for Microbial Fuel Cells

Microbial fuel cell (MFC) technology holds significant promise for the production of clean energy and treatment of pollutants. Nevertheless, challenges such as low power generation efficiency and the high cost of electrode materials have impeded its widespread adoption. The porous microstructure of biochar and the exceptional photocatalytic properties of rutile endow it with promising catalytic potential. In this investigation, we synthesized a novel Rutile–Biochar (Rut-Bio) composite material using biochar as a carrier and natural rutile, and explored its effectiveness as a cathode catalyst to enhance the power generation efficiency of MFCs, as well as its application in remediating heavy metal pollution. Furthermore, the impact of visible light conditions on its performance enhancement was explored. The X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) analysis validated the successful fabrication of rutile composites loaded with biochar. The maximum current density and power density achieved by the MFCs were 153.9 mA/m2 and 10.44 mW/m2, respectively, representing a substantial increase of 113.5% and 225% compared to the control group. In addition, biochar-supported rutile MFCs showed excellent degradation performance of heavy metal pollutants under light conditions. Within 7 h, the Cr6+ degradation rate reached 95%. In contrast to the blank control group, the removal efficiency of pollutants exhibited increases of 630.8%. The cyclic degradation experiments also showcased the remarkable stability of the system over multiple cycles. This study successfully integrated natural rutile and biochar to fabricate highly efficient cathode photocatalyst composites, which not only enhanced the power generation performance of MFCs but also presented an environmentally sustainable and economically viable method for addressing heavy metal pollution.