Engineering the Band-Edge of Fe2O3/ZnO Nanoplates via Separate Dual Cation Incorporation for Efficient Photocatalytic Performance

Synthesis and Characterization of Naproxen Intercalated Zinc Oxide Stacked Nanosheets for Enhanced Hepatoprotective Potential

Liver diseases pose a significant global health burden, with limited therapeutic options for chronic cases. Zinc oxide (ZnO) nanomaterials have emerged as promising candidates for hepatoprotection due to their antioxidant, anti-inflammatory, and regenerative properties. However, their potential remains hampered by insufficient drug loading and controlled release. The current study explores the intercalation of Naproxen (Nx), a potent anti-inflammatory and analgesic drug, within ZnO stacked nanosheets (SNSs) to address these limitations. Herein, an easy and solution-based synthesis of novel Nx intercalated ZnO SNSs was established. The obtained Nx intercalated ZnO SNSs were encapsulated with poly(vinyl acetate) (PVA) to make them biocompatible. The synthesized biocomposite was characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR), which confirm the successful synthesis and intercalation of Nx within the ZnO SNSs. The obtained outcomes showed that the configuration of ZnO nanosheets was altered when Nx was introduced, resulting in a more organized stacking pattern. An in vivo investigation of mice liver cells unveiled that the Nx intercalated ZnO SNss had increased hepatoprotective properties. The study's results provide valuable insights into using Nx intercalated ZnO SNss for targeted drug delivery and improved treatment effectiveness, particularly for liver-related illnesses.

Interfacial engineering of 1D/2D heterostructured photoanode for efficient photoelectrochemical water splitting

Solar-driven photoelectrochemical (PEC) water splitting for hydrogen generation is regarded as a sustainable strategy to relieve fossil resource issue. However, its PEC conversion efficiency still suffers from the low light absorption and high electron-hole recombination. Herein, we report 1D/2D hierarchical heterostructured photoelectrode constructed by ordered ZnO nanorod array and intimately attached ultra-thin Hematene (thickness of monolayer: 1-2 nm) for effective PEC water oxidation with visible light irradiation. The onset potential of Hematene/ZnO NRs photoanode (0.28 V versus RHE) for PEC water oxidation has an obvious negative shift compared with that of ZnO NRs (0.32 V versus RHE) indicating the enhanced PEC kinetics. Furthermore, reduced charge transport resistance (18.82 KΩ cm^-2), a high carrier density of 9.03 × 10¹⁸cm^-3and the resulting significantly enhanced incident photon-to-current efficiency enhancement compared with ZnO NRs photoanode were obtained for Hematene/ZnO NRs photoanode. All these were ascribed to the formation of large built-in electric field which was arising from the charge redistribution at the ZnO and Hematene interface, and the band alignment engineering between the components. In summary, such interfacial engineering may inspire the future development of 1D/2D hierarchical heterostructured photoanodes in the field of PEC water splitting.

Green Biosynthesis of Tin Oxide Nanomaterials Mediated by Agro-Waste Cotton Boll Peel Extracts for the Remediation of Environmental Pollutant Dyes

The sustainable synthesis of metal oxide materials provides an ecofriendly and more exciting approach in the domain of a clean environment. Besides, plant extracts to synthesize nanoparticles have been considered one of the more superior ecofriendly methods. This paper describes the biosynthetic preparation route of three different sizes of tetragonal structure SnO₂ nanoparticles (SNPs) from the agro-waste cotton boll peel aqueous extract at 200, 500, and 800 °C for 3 h and represents a low-cost and alternative preparation method. The samples were characterized by X-ray diffraction, Fourier transform infrared spectrophotometry, ultraviolet-visible absorption spectroscopy, high-resolution transmission electron microscopy (HR-TEM), and energy-dispersive X-ray spectroscopy. Surface area and porosity size distribution were identified by nitrogen adsorption-desorption isotherms and Brunauer-Emmett-Teller analysis. The photocatalytic properties of the SNP samples were studied against methylene blue (MB) and methyl orange (MO), and the degradation was evaluated with three different size nanomaterials of 3.97, 8.48, and 13.43 nm. Photocatalytic activities were carried out under a multilamp (125 W Hg lamps) photoreactor. The smallest size sample exhibited the highest MB degradation efficiency within 30 min than the most significant size sample, which lasted 80 min. Similarly, in the case of MO, the smallest sample showed a more superior degradation efficiency with a shorter period (40 min) than the large-size samples (100 min). Therefore, our studies suggested that the developed SNP nanomaterials could be potential, promising photocatalysts against the degradation of industrial effluents.

Synthesis of Biogenic Silver Nanocatalyst and their Antibacterial and Organic Pollutants Reduction Ability

Plant-mediated nanoparticles are gaining popularity due to biologically active secondary metabolites that aid in green synthesis. This study describes a simple, environmentally friendly, dependable, and cost-effective production of silver nanoparticles utilizing Cucumis sativus and Aloe vera aqueous leaf extracts. The aqueous leaf extracts of Cucumis sativus and Aloe vera, which worked as a reducing and capping agent, were used to biosynthesize silver nanoparticles (AgNPs). The formation of surface plasmon resonance peaks at 403 and 405 nm corresponds to the formation of colloidal Ag nanoparticles. Similarly, the Bragg reflection peaks in X-ray diffraction patterns observed at 2θ values of 38.01°, 43.98°, 64.24°, and 77.12° representing the planes of [111], [200], [220], and [311] correspond to the face-centered cubic crystal structure of silver nanoparticles. Fourier transform infrared spectroscopy confirms that bioactive chemicals are responsible for the capping of biogenic silver nanoparticles. The size, structure, and morphology of AgNPs with diameters ranging from 8 to 15 nm were examined using transmission electron microscopy. Water contamination by azo dyes and nitrophenols is becoming a more significant threat every day. The catalytic breakdown of organic azo dye methyl orange (MO) and the conversion of para-nitrophenol (PNP) into para-aminophenol using sodium borohydride was evaluated using the prepared biogenic nanoparticles. Our nanoparticles showed excellent reduction ability against PNP and MO with rate constants of 1.51 × 10^-3 and 6.03 × 10^-4s^-1, respectively. The antibacterial activity of the nanomaterials was also tested against four bacteria: Staphylococcus aureus, Klebsiella pneumoniae, Enterobacter, and Streptococcus pneumoniae. These biogenic AgNPs displayed effective catalytic and antibacterial characteristics by reducing MO and PNP and decreasing bacterial growth.

Ball-milled bismuth oxybromide/biochar composites with enhanced removal of reactive red owing to the synergy between adsorption and photodegradation

In this paper, bismuth oxybromide (BiOBr)/biochar composites were synthesized by a facile ball milling method for synergistic adsorption and photodegradation of Reactive red 120 (RR120). The characterizations show that ball milling changed the degree of crystallization, increased the surface area, and promoted the charge transfer ability of biochar. The 70% BiOBr/BC composite showed the best removal efficiency for RR120 removal with or without light illumination, which proves its enhanced removal ability by adsorption and photodegradation. The biochar is served as a support of BiOBr for preventing its aggregation and a transporter of charges for promoting the separation of photo-induced carriers in composites. BiOBr can release the adsorption sites on the surface of composites by degradation, which facilitated the RR120 removal and regenerated the photocatalyst for reusing. The strong interactions between BiOBr and biochar in composites resulted from ball milling were beneficial for the charge transfer and synergistic removal of adsorption and degradation. Findings of this work indicate that ball milling method is an effective method to prepare highly efficient biochar-based composites for RR120 removal through synergistic adsorption and photodegradation.

Visible light-driven photocatalytic rapid degradation of organic contaminants engaging manganese dioxide-incorporated iron oxide three dimensional nanoflowers

Water pollution via hazardous organic pollutants poses a high threat to the environment and globally imperils aquatic life and human health. Therefore, the elimination of toxic organic waste from water sources is vital to ensure a healthy green environment. In the current work, we synthesized α-MnO₂-Fe₃O₄ 3D-flower like structure using a two-step hydrothermal method and explored the combination in a visible-light-assisted photocatalytic degrdation of dyes. The attained high specific surface area of 82 m²/g with mesoporous nature of α-MnO₂ and Fe₃O₄ together can generate more active sites after exposure to visible light, leading to remarkable photodegradation performance. Significantly, twofold higher dye (methylene blue, MB (94.8%/120 min; crystal violet, CV (93.7%/120 min)) and drug (LVO 91%/90 min) photodegradations were observed with α-MnO₂-Fe₃O₄ as catalyst than pure α-MnO₂ and Fe₃O₄ at pH 6, respectively. This is attributed to the higher surface area and synergistic effect between Mn and Fe. More than 85% stability was observed with optimized catalysts employing MB and CV dyes, demonstrating the excellent reusability of the α-MnO₂-Fe₃O₄. The underlying mechanism indicates that the formation of reactive oxygen species predominantly plays a role in the photodegradation of dyes under visible light. Consequently, these new insights will shed light on the practical applications of the α-MnO₂-Fe₃O₄ 3D-flower-like spherical structure for eco-friendly remediation via wastewater treatment.

Magnetic field assisted α-Fe2O3/Zn1-xFexO heterojunctions for accelerating antiviral agents degradation under visible-light

Reducing the recombination efficiency of photo-induced carriers has been found as an effective means to improve the degradation of antiviral agents. Given that the Lorentz forces can cause the abnormal charge to move in the opposite direction, external magnetic field improved α-Fe₂O₃/Zn_1-xFe_xO heterojunctions (FZHx) were developed to remove increasing antiviral agents that were attributed to the COVID-19 pandemic under visible light. The characterization of the mentioned FZHx in the external magnetic field indicated that FZHx had perfect photocatalytic activity for degrading antiviral agents. In the external magnetic field, the quantities of photo-generated carriers and free radicals (•OH and •O₂ ^-) derived from FZHx increased significantly, which improved antiviral agent removal by 30.0%. Though the band structure (α-Fe₂O₃) is unlikely to change due to some orders of magnitude weaker of Zeeman energy in magnetic fields, which insignificantly impacts photocatalytic performance. However, this study proposed a strategy of negative magnetoresistance effects and heterojunctions to facilitate the separation and transfer of photo-induced carriers in magnetic fields. Based on the proposed strategy, spin oriented electrons were selected and accumulated on the conduction band, which contributed to the degradation of antiviral agents. Overall, this study presented novel insights into the improved degradation performance of antiviral agents by applying Fe-based heterojunctions in an external magnetic field.

Direct Z-scheme MgIn2S4/TiO2heterojunction for enhanced photocathodic protection of metals under visible light

To improve the photocathodic protection performance of traditional TiO₂photoanodes for metals, constructing a Z-scheme heterojunction is one of the most promising and creative strategies. Herein, we fabricated a novel Z-scheme MgIn₂S₄nanosheets/TiO₂nanotube nanocomposite through anodization and hydrothermal method. The optimized Z-scheme MgIn₂S₄/TiO₂nanocomposites exhibited stronger visible light absorption, higher separation efficiency of photoelectrons and photocathodic protection performances in comparison to pure TiO₂. The theoretical analysis and experimental results show that the Z-scheme heterojunction and oxygen vacancies jointly improved the separation efficiency of photogenerated electron-hole pairs and visible light absorption capacity, thereby improving the photoelectric conversion performance of the MgIn₂S₄/TiO₂nanocomposites. Furthermore, the influence of the precursor solution concentration on the photocathodic protection performances of the composites was investigated. As a result, when the concentration of magnesium source in the precursor solution was 0.06 mmol, the prepared MgIn₂S₄/TiO₂-0.06 displayed the best photocathodic protection performance. In addition, the hydroxyl radicals (·OH) generated in the electron spin resonance (ESR) experiment verified the Z-scheme heterojunction mechanism of the MgIn₂S₄/TiO₂composite, and also demonstrated the excellent redox performance of the composite. This work provides valuable reference for the construction of high-performance Z-scheme heterojunctions for photocathode protection of metals.

Interconnecting 3D Conductive Networks with Nanostructured Iron/Iron Oxide Enables a High-Performance Flexible Battery

Aqueous Ni/Fe alkaline batteries with features of low cost and high safety show great potential for application in portable and wearable electronics. However, the poor kinetics of the Fe-based anode greatly limits the large-scale applications of Ni/Fe batteries. Herein, we report an interconnected 3D conductive network with carbon-coated nanostructured iron/iron oxide (3D-Fe/Fe₂O₃@C) as an efficient anode for a flexible Ni/Fe battery. A hydrogel precursor is used to molecularly link and confine Fe³⁺ to spatial networks, resulting in a uniform dispersion of Fe/Fe₂O₃-heterostructured nanoparticles. Theoretical investigations reveal regulated potential loss and improved delocalized carrier density as a result of carbon coating and the mixed metal/metal oxide structure. In addition to these merits, due to the regulated wettability and electroactive surface areas, the 3D-Fe/Fe₂O₃@C anode with a high mass loading delivers an extraordinary areal capacity of 3.07 mA h cm^-2, as well as the boosted rate capability and Coulombic efficiency. When coupled with the NiCo₂O₄ cathode, the flexible quasi-solid-state Ni/Fe battery exhibits an admirable energy density of 15.53 mW h cm^-3 and a maximum power density of 761.91 W h cm^-3. The good stability after 20,000 cycles and severe mechanical deformations of the as-fabricated Ni/Fe battery imply it as a promising flexible energy storage device for practical applications.

Sn-Controlled Co-Doped Hematite for Efficient Solar-Assisted Chargeable Zn-Air Batteries

The photoelectrochemical performance of a co-doped hematite photoanode might be hindered due to the unintentionally diffused Sn from a fluorine-doped tin oxide (FTO) substrate during the high-temperature annealing process by providing an increased number of recombination centers and structural disorder. We employed a two-step annealing process to manipulate the Sn concentration in co-doped hematite. The Sn content [Sn/(Sn + Fe)] of a two-step annealing sample decreased to 1.8 from 6.9% of a one-step annealing sample. Si and Sn co-doped hematite with the reduced Sn content exhibited less structural disorder and improved charge transport ability to achieve a 3.0 mA cm^-2 photocurrent density at 1.23 V_RHE, which was 1.3-fold higher than that of the reference Si and Sn co-doped Fe₂O₃ (2.3 mA cm^-2). By decorating with the efficient co-catalyst NiFe(OH)_x, a maximum photocurrent density of 3.57 mA cm^-2 was achieved. We further confirmed that the high charging potential and poor cyclability of the zinc-air battery could be dramatically improved by assembling the optimized, stable, and low-cost hematite photocatalyst with excellent OER performance as a substitute for expensive Ir/C in the solar-assisted chargeable battery. This study demonstrates the significance of manipulating the unintentionally diffused Sn content diffused from FTO to maximize the OER performance of the co-doped hematite.

Sub-Thick Electrodes with Enhanced Transport Kinetics via In Situ Epitaxial Heterogeneous Interfaces for High Areal-Capacity Lithium Ion Batteries

The ever-growing portable electronics and electric vehicle draws the attention of scaling up of energy storage systems with high areal-capacity. The concept of thick electrode designs has been used to improve the active mass loading toward achieving high overall energy density. However, the poor rate capabilities of electrode material owing to increasing electrode thickness significantly affect the rapid transportation of ionic and electron diffusion kinetics. Herein, a new concept named "sub-thick electrodes" is successfully introduced to mitigate the Li-ion storage performance of electrodes. This is achieved by using commercial nickel foam (NF) to develop a monolithic 3D with rich in situ heterogeneous interfaces anode (Cu₃ P-Ni₂ P-NiO, denoted NF-CNNOP) to reinforce the adhesive force of the active materials on NF as well as contribute additional capacity to the electrode. The as-prepared NF-CNNOP electrode displays high reversible and rate areal capacities of 6.81 and 1.50 mAh cm^-2 at 0.40 and 6.0 mA cm^-2 , respectively. The enhanced Li-ion storage capability is attributed to the in situ interfacial engineering within the NiO, Ni₂ P, and Cu₃ P and the 3D consecutive electron conductive network. In addition, cyclic voltammetry, charge-discharge curves, and symmetric cell electrochemical impedance spectroscopy consistently reveal improved pseudocapacitance with enhanced transports kinetics in this sub-thick electrodes.

Ethylene glycol-mediated one-pot synthesis of Fe incorporated α-Ni(OH)2 nanosheets with enhanced intrinsic electrocatalytic activity and long-term stability for alkaline water oxidation

Sustainable electrocatalytic water splitting stipulates the development of cheap, efficient and stable electrocatalysts to promote comparatively sluggish oxygen evolution reaction. We have synthesized iron-incorporated pure phase α-nickel hydroxide, Ni0.8Fe0.2(OH)2 electrocatalyst utilizing N,N,N',N'-Tetramethylethane-1,2-diamine (TMEDA) and ethylene glycol (EG) following a simple one-pot synthesis process. PXRD and FTIR data suggest that the intercalation of EG in the interlayer spacing promotes amorphousness of the material. FESEM and TEM analyses suggest that the catalyst possesses hierarchical sheet-like morphology and BET measurements indicated the surface area of 50 m2 g-1 with high mesoporosity. Electrochemical studies suggest that Ni0.8Fe0.2(OH)2 prepared using water-EG mixture is the most efficient electrocatalyst for OER activity as it requires only 258 mV overpotential (considering backward LSV) on a glassy carbon electrode to achieve the benchmark current density of 10 mA cm-2geo. Additionally, the catalyst shows remarkable long-term stability for up to 7 days. The efficiency of Ni0.8Fe0.2(OH)2 electrocatalyst is reflected in its low Tafel slope (43 mV dec-1) and high OER faradaic efficiency (93%). The enhanced activity is attributed to the increase in the interlayer spacing due to the intercalation of EG into the material, which facilitates the transport of ions during the OER process. The overall improved catalytic property is due to the enhanced ionic mobility, controllable textural property, higher per-site activity and increased conductivity for the Ni0.8Fe0.2(OH)2 catalytic network.

Facile synthesis, characterization, mechanism and enhanced visible-light photocatalytic activity of SiW12/α-Fe2O3 nanocomposites

The photocatalytic mechanism of the SiW12/α-Fe2O3 nanohybrid.

Defect Engineering Enhances the Charge Separation of CeO2 Nanorods toward Photocatalytic Methyl Blue Oxidation

Defect-rich photocatalytic materials with excellent charge transfer properties are very popular. Herein, Sm-doped CeO₂ nanorods were annealed in a N₂ atmosphere to obtain the defective Sm-doped CeO₂ photocatalysts (Vo–Sm–CeO₂). The morphology and structure of Vo–Sm–CeO₂ were systematically characterized. The Vo–Sm–CeO₂ nanorods demonstrated an excellent photodegradation performance of methyl blue under visible light irradiation compared to CeO₂ nanorods and Sm–CeO₂. Reactive oxygen species including OH, ·O₂⁻, and h⁺ were confirmed to play a pivotal role in the removal of pollutants via electron spin resonance spectroscopy. Doping Sm enhances the conductivity of CeO₂ nanorods, benefiting photogenerated electrons being removed from the surface reactive sites, resulting in the superior performance.