Coconut Shell Carbon Preparation for Rhodamine B Adsorption and Mechanism Study.

Phosphoric acid is used as a chemical activator to prepare coconut shell carbon (PCSC), and for investigating rhodamine B (RhB) adsorption performance. The optimal conditions for the preparation of PCSC (calcined temperature, phosphoric acid concentration), and the influence of adsorption conditions (concentration, pH, etc.) on RhB and the recovery performance of optimal carbon are investigated. Experimental results show that when the amount of PCSC (600 °C, 2 h) is 0.2 g, the initial RhB concentration is 10 mg/L, pH = 6, and the adsorption time is 30 min, it can have 95.84% RhB adsorption efficiency. Liquid ultraviolet spectroscopy also supports this adsorption performance. Characterization data showed that hydroxyl and ester groups, aromatic structures, and PO43- existed on the surface of PCSC, and the amount decreased with increasing calcined temperature. PCSC has a BET (N2) surface area of 408.59 m2/g and has a micropore distribution, EDS-detected P content is 3.91%. SEM showed that the PCSC formed micropores which could better adsorb RhB. The kinetic and thermodynamic analysis of the adsorption of RhB by PCSC showed that the adsorption process was in accord with quasi-secondary kinetic equations and ΔGθ was between -1.65 and -18.75 kJ/mol. The adsorption was a physical adsorption and a spontaneous endothermic reaction, and the obtained PCSC sorption isotherms were classified as Langmuir-type. The RhB adsorption mechanism on PCSC includes pore diffusion, hydrogen bonding, and π-π conjugation. The PCSC prepared by H3PO4 modification has superior adsorption and recycling performance for RhB, providing a reference for the preparation of other biomass carbon materials for the treatment of dye wastewater.

Effect of Thiophene-Hydrazinyl-Thiazole derivative as an efficient dye sensitizer and performance enhancer of TiO2 toward Rhodamine B photodegradation.

Visible-light-driven photocatalysis is an eco-friendly technology for wastewater treatment, where TiO2-based photocatalysts displayed outstanding performance in this regard. Dye sensitization is a promising approach for overcoming the common drawbacks of TiO2 via improving its photocatalytic performance and extending its activity to visible light. Herein, we demonstrate the synthesis of the Thiophene-Hydrazinyl-Thiazole (THT) derivative as a novel organic dye sensitizer to be employed as a visible-light antenna for TiO2 nanoparticles. The physicochemical characteristics of the as-synthesized TiO2-based nanoparticles are examined by different techniques, which revealed the successful fabrication of the proposed THT-TiO2 heterojunction. The incorporation of THT molecules on the TiO2 surface led to slight disorders and deformation in the crystal lattice of TiO2, a remarkable improvement of its absorption in the visible light as a perfect visible-light antenna in the whole visible region, and significant enhancement in the charge transfer. Rhodamine B (RhB) is used as an organic dye model to assess the photocatalytic efficiency of the as-fabricated THT-TiO2 photocatalyst which achieved almost complete degradation (>95% in 150 min) with an observed rate constant (kobs) of 0.0164 min-1; total organic carbon (TOC) measurements suggest ∼75% mineralization. THT-TiO2 achieved 2.1-fold enhancement in photodegradation% and 4.1-fold enhancement in kobs compared to the bare TiO2. THT showed good activity under visible-light irradiation (RhB degradation% was >66% in 150 min and kobs=0.0085 min-1). The influence of the initial pH of the solution was investigated and pH 4 was the optimum pH value for suitable interaction between RhB and the surface of THT-TiO2. Radical quenching experiments were conducted to assess the crucial reactive species where the ∙OH and were the most reactive species. THT-TiO2 showed promising stability over three successive cycles. Finally, the improvement mechanism of the photocatalytic activity of THT-TiO2 was attributed to the electron injection from the excited THT (the dye sensitizer) to TiO2 and enhanced charge separation.

Methylene Blue and Rhodamine B Dyes' Efficient Removal Using Biocarbons Developed from Waste.

The preparation of biocarbons from cellulose fibres utilised in the production of baby nappy mats (sourced from Feniks Recycling company, Poland) for the removal of methylene blue and rhodamine B dyes has been documented. A Brunauer, Emmett and Teller analysis revealed a surface area within the range of 384 to 450 m2/g. The objective of this study was to investigate the removal efficiency of dyes from aqueous solutions by biocarbons, with a particular focus on the influence of various parameters, including pH, dye concentration, adsorbent dosage, shaking speed, contact time, and temperature. The maximum adsorption capacity of the dyes onto the biocarbons was found to be 85 mg/g for methylene blue and 48 mg/g for rhodamine B, respectively. The Langmuir equation proved to be the most suitable for interpreting the sorption of organic dyes. The adsorption process was found to exhibit a chemisorption mechanism, effectively mirroring the pseudo-second-order kinetics. Furthermore, the adsorption of dyes was observed to be endothermic (the enthalpy change was positive, 9.1-62.6 kJ/mol) and spontaneous under the tested operating conditions. The findings of this study indicate that biocarbons represent a cost-effective option for the removal of methylene blue and rhodamine B. The adsorption method was observed to be an effective and straightforward approach for the removal of these dyes. The results of the Boehm titration analysis and zero charge point value indicated that the synthesised biomaterials exhibited a slightly basic surface character.

Magnetic-responsive sensors based on polydopamine macromolecules for highly sensitive detection of trace food colorant residues.

As a kind of unique biomimetic macromolecule, polydopamine (PDA) have prominent in-situ reduction ability and interfacial adhesion. In this work, combined with in-situ reduction ability of PDA and excellent magnetic response performance of nickel foam (NF), a strategy was designed to fabricate a series of NF@PDA@AgNPs as magnetic-responsive surface enhancement Raman scattering (SERS) substrates for highly sensitive Rhodamine B (RhB) detection in chili powder. With crystal violet (CV) as probe molecule, the detection limit of SERS substrate could achieve 10-10 M, and the enhancement factor was as high as to 2.22 × 107. In addition, the NF@PDA@AgNPs SERS substrates showed excellent magnetic separation efficiency, good SERS uniformity and storage stability. More importantly, these substrates could achieve highly efficient collection and sensitive detection of RhB residues in chili powder by magnetic adsorption method, and the detection of limit was as low as to be 10-6 g/g. These NF@PDA@AgNPs substrates would be a great prospect for rapid and efficient pernicious contaminant detection in the chemical and biological fields.

Synthesis and Characterization of Cr doped CeO2 nanoparticles for Rhodamine B dye degradation.

The main aim of this work is to synthesis and study Cr doped CeO2 nanoparticles for Rhodamine B dye degradation. In this regard, 2 wt% and 4 wt% Cr doped CeO2 nanoparticles were successfully synthesized through a simple chemical precipitation method. The structural characteristics and elemental composition of the synthesized samples were analyzed using XRD and XPS techniques. The cubic fluorite structure with space group Fm 3m was confirmed through XRD and the presence of Ce, O and Cr atoms in the samples were identified through XPS. Spindle shaped structures were observed from FESEM analysis for 2 % Cr doped sample. Confocal Raman Spectroscopy was used to confirm the CeO2 stretching vibrational mode at 469 cm-1. The metal oxygen band was obtained at 447.49 cm-1 from FTIR spectroscopy. The band gap values were calculated from the Tauc plot and the values were found to be 2.0 eV, 2.85 eV and 2.88 eV for CeO2, 2 % Cr and 4 % Cr doped samples. The prepared nanoparticles were subjected to photocatalytic degradation of Rhodamine B dye at 5 ppm concentration and highest efficiency of 98.3 % was observed by the 4 % Cr doped CeO2 sample.

Investigation of the efficacy of graphite-sulfur iron tailing composite catalysts for activation of peroxydisulfate for rhodamine B degradation.

Herein, a novel graphite/sulfur iron tailing composite was applied as a peroxydisulfate (PDS) activator for rhodamine B (RhB) degradation in the water. The superior catalytic efficiency of graphite/sulfur iron tailing was achieved through radical (SO4•- and •OH) and non-radical (1O2) processes according to the radical quenching experiments and electron paramagnetic resonance analysis. The carbonyl group and Fe species were the main active sites on the surface of graphite/sulfur iron tailing, which was demonstrated by combining Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), and reaction kinetic experiments, and a possible degradation mechanism was also proposed. Overall, activated with 0.30 g/L of C-1, PDS achieved a 94.8% removal rate for RhB and maintained a removal rate of over 85% even after five consecutive operation cycles, and this study will benefit the application of iron/carbon composite materials in practical water treatment.

One-Step Self-Assembled WO3/rGO Microspheres Photoanode Assembled Efficient Photocatalytic Fuel Cells for Simultaneous Organic Pollutant Degradation and Electricity Generation.

Photocatalytic fuel cells (PFCs) present a promising and environmentally friendly approach to simultaneously treat organic pollutants in wastewater and electricity generation. The development of photoanodes with high light absorption and carrier mobility is essential for enhancing the performance of PFCs but remains challenging. Herein, a one-step self-assembly strategy was adopted to develop flower-like WO3/rGO microspheres for PFC devices. Attributed to the abundant surface-active sites, enhanced light harvesting, and efficient separation of photogenerated charge carriers, the WO3/rGO photoanode demonstrated superior rhodamine B (RhB) degradation rate (90% in 2 h), maximum power density (4.74 µW/cm2), and maximum photocurrent density (0.096 mA/cm2), 1.4, 2.4, and 4.0 times higher than the corresponding pure WO3 photoanode, respectively. Density functional theory (DFT) calculations reveal that the built-in electric field formed between the interface of WO3 and rGO promotes the transfer of photogenerated electrons from WO3 to rGO, thus exerting a significant impact on improving the migration and separation of photoinduced charge carriers. Moreover, by combining experimental and theoretical results, a complete PFC operation mechanism for the PFC system was proposed. This study focuses on the strategy of constructing rGO-doped photocatalysts to enhance the interfacial charge transfer mechanism, providing a promising approach for the development of high-performance photoanodes in PFC systems.

Preparation of functionalized porous chitin carbon to enhance the H2O2 production and Fe3+ reduction properties of Electro-Fenton cathodes for efficient degradation of RhB.

The performance of Electro-Fenton (EF) cathode materials is primarily assessed by H2O2 yield and Fe3+ reduction efficiency. This study explores the impact of pore structure in chitin-based porous carbon on EF cathode effectiveness. We fabricated mesoporous carbon (CPC-700-2) and microporous carbon (ZPC-700-3) using template and activation methods, retaining nitrogen from the precursors. CPC-700-2, with mesopores (3-5 nm), enhanced O2 diffusion and oxygen reduction, producing up to 778 mg/L of H2O2 in 90 min. ZPC-700-3, with a specific surface area of 1059.83 m2/g, facilitated electron transport and ion diffusion, achieving a Fe2+/Fe3+ conversion rate of 79.9%. EF systems employing CPC-700-2 or ZPC-700-3 as the cathode exhibited superior degradation performance, achieving 99% degradation of Rhodamine B, efficient degradation, and noticeable decolorization. This study provides a reference for the preparation of functionalized carbon cathode materials for efficient H2O2 production and effective Fe3+ reduction in EF systems.

Hybridization of Polymer-Encapsulated MoS2-ZnO Nanostructures as Organic-Inorganic Polymer Films for Sonocatalytic-Induced Dye Degradation.

The development of environmentally friendly technology is vital to effectively address the issues related to environmental deterioration. This work integrates ZnO-decorated MoS2 (MZ) to create a high-performing PVDF-based PVDF/MoS2-ZnO (PMZ) hybrid polymer composite film for sonocatalytic organic pollutant degradation. An efficient synergistic combination of MZ was identified by altering the ratio, and its influence on PVDF was assessed using diverse structural, morphological, and sonocatalytic performances. The PMZ film demonstrated very effective sonocatalytic characteristics by degrading rhodamine B (RhB) dye with a degradation efficiency of 97.23%, whereas PVDF only degraded 17.7%. Combining MoS2 and ZnO reduces electron-hole recombination and increases the sonocatalytic degradation performance. Moreover, an ideal piezoelectric PVDF polymer with MZ enhances polarization to improve redox processes and dye degradation, ultimately increasing the degradation efficiency. The degradation efficiency of RhB was seen to decrease while employing isopropanol (IPA) and p-benzoquinone (BQ) due to the presence of reactive oxygen species. This suggests that the active species •O2- and •OH are primarily responsible for the degradation of RhB utilizing PMZ2 film. The PMZ film exhibited improved reusability without substantially decreasing its catalytic activity. The superior embellishment of ZnO onto MoS2 and effective integration of MZ into the PVDF polymer film results in improved degrading performance.

Synthesis of a Multi-Stimulus Responsive RGB Fluorescent Organic Molecule based on Dark Through-Bond Energy Transfer Mechanism.

In this study, a novel multi-stimulus responsive RGB fluorescent organic molecule, RTPE-NH2, was designed and synthesized based on the combination of aggregation-induced emission tetraphenylethylene (TPE) luminophore and acid-responsive fluorescent molecular switch Rhodamine B. RTPE-NH2 exhibits aggregation-induced emission behavior, as well as UV irradiation-stimulus and acid-stimulus responsive fluorescence properties. It could emit orange-red (R), green(G), and blue(B) light in both solution and PMMA film under 365 nm excitation. The dark through-bond energy transfer (DTBET) mechanism was proposed and supported by control experiments and TD-DFT calculations. The synthesis and application of RTPE-NH2 could accelerate the development of organic smart materials with high sensitivity and excellent optical properties.

A Dual Emission Fluorescence Probe Based on Silicon Nanoparticles and Rhodamine B for Ratiometric Detection of Kaempferol.

In this paper, blue fluorescent silicon nanoparticles (SiNPs) with outstanding optical properties and robust stability were synthesized by a simple one-step hydrothermal method. By introducing red emissive rhodamine B (RhB) into SiNPs solution, a dual emission nanoprobe (SiNPs@RhB) was constructed, which showed excellent pH stability, salt resistance and photobleaching resistance. The SiNPs@RhB probe could emit two peaks at 444 nm and 583 nm under 365 nm excitation. It was found that the fluorescence intensity of the two emission peaks decreased in different degrees with the addition of different concentrations of kaempferol (Kae). According to this phenomenon, a novel ratiometric fluorescence method was established for the detection of Kae via utilizing SiNPs@RhB as nanoprobe. The detection range and limit of detection (LOD) were 0.5 ~ 150 µM and 0.24 µM, respectively. The ratiometric fluorescence method exhibited the superiority of rapid detection, excellent stability, wide linear range and high sensitivity. The detection mechanism was studied by ultraviolet visible absorption spectra, fluorescence spectra and fluorescence lifetime. Furthermore, the method was applied to the detection of Kae in real samples (kaempferia powder, sea buckthorn granules and sea buckthorn dry emulsion).

Removal of Rhodamine-B dye from Aqueous Solutions Using Alkaline-Modified Activated Carbon from Cocoa Pod Husk.

Rhodamine-B (RhB) dye in wastewater poses health and environmental risks due to respiratory and eye infections, neurotoxicity, and carcinogenicity, necessitating proper disposal for risk mitigation. This study investigates RhB removal from water using NaOH-modified activated carbon derived from cocoa pod husk (CPHAC). Employing a face-centered central composite design, operational variables were optimized to achieve maximum RhB dye removal efficiency. The study reveals a removal efficiency of 98.87 ± 0.84% under optimized conditions: adsorbent dose of 1.34 g, contact time of 71.59 min, and an initial RhB concentration of 6.61 ppm. The Freundlich isotherm model demonstrated a good fit, suggesting that RhB removal is governed by heterogeneity and multilayer adsorption. Kinetic experiments revealed that adsorption follows a pseudo-second-order model, indicating likely irreversible adsorption with dye molecules forming chemical bonds on CPHAC's surface. Overall, this study demonstrates the effectiveness of CPHAC as an efficient adsorbent for RhB removal from water.

Bioinspired copper oxide nanocomposites: harnessing plant extracts for enhanced photocatalytic performance.

This study focuses on developing copper oxide-based nanocomposites using plant extracts for photocatalytic applications. Curcuma amada leaf and Alysicarpus vaginalis leaf extracts were utilized alongside recycled copper precursors to synthesize photocatalysts via a green synthesis approach. Structural characterization through X-ray diffraction confirmed the formation of monoclinic CuO with reduced crystallite sizes due to plant extract incorporation. Fourier-transform infrared spectroscopy identified additional functional groups from the plant extracts, enhancing the material's properties. UV-Vis spectroscopy demonstrated increased light absorption and narrowed bandgaps in the nanocomposites, crucial for efficient photocatalysis under visible light. Morphological studies using FESEM revealed unique leaf-like structures in nanocomposites, indicative of the plant extract's influence on morphology. Photocatalytic degradation of methylene blue, rhodamine B, Congo red, and reactive blue 171 dyes showed enhanced performance of plant extract-modified CuO compared to without plant extract mediated CuO, attributed to improved charge carrier separation and extended lifetime. The effects of pH, catalyst dosage, and dye concentration on degradation efficiency were systematically investigated, highlighting optimal conditions for each dye type. Radical scavenger studies confirmed the roles of holes and hydroxyl radicals in the degradation process. Kinetic analysis revealed pseudo-second-order kinetics for dye degradation, underscoring the effectiveness of the nanocomposites. Overall, this research provides insights into sustainable photocatalytic materials using plant extracts and recycled copper, showcasing their potential for environmental remediation applications.

Comparison of surface adsorption efficacies of eco-sustainable agro/animal biomass-derived activated carbon for the removal of rhodamine B and hexavalent chromium.

Effective management and remediation strategies are crucial to minimize the impacts of both organic and inorganic contaminants on environmental quality and human health. This study investigates a novel approach utilizing cotton shell activated carbon (CSAC), rice husk activated carbon (RHAC), and wasp hive activated carbon (WHAC), produced through alkali treatment and carbonization under N2 atmosphere at 600 °C. The adsorption capacities of biomass-derived mesoporous activated carbons (CSAC, RHAC, WHAC) alongside macroporous commercial activated carbons (CAC) were evaluated for removing rhodamine B (Rh B) and hexavalent chromium (Cr6+). The CSAC exhibits remarkable adsorption efficiency (255.4 mg.g-1) for Cr(VI) removal, while RHAC demonstrates superior efficacy (174.2 mg.g-1) for Rh B adsorption. Investigating various optimal parameters including initial pH (pH 3 for Cr and pH 7 for Rh B), catalyst dosage (200 mg.L-1), and initial concentration (20 mg.L-1), the Redlich-Peterson isotherm model is applied to reveal a hybrid adsorption mechanism encompassing monolayer (chemisorption) and multilayer (van der Waals adsorption) processes. Kinetic analysis highlights the pseudo-second-order and Elovich models as the most suitable, suggesting physiochemisorption mechanisms. Thermodynamic analysis indicates the endothermic nature of the adsorption process, with increased randomness at the solid-solution interface. Isosteric heat investigations using Clausius-Clapeyron, Arrhenius, and Eyring equations reveal a heterogeneous surface nature across all activated carbons. Further confirmation of Rh B and Cr(VI) adsorption onto activated carbons is provided through FTIR, FESEM, and EDAX analysis. This study highlights the innovation and promise of utilizing biomass-derived activated carbons for effective pollutant removal.

TiO2 Nanoparticles with Adjustable Phase Composition Prepared by an Inverse Microemulsion Method: Physicochemical Characterization and Photocatalytic Properties.

Titania nanoparticles (NPs) find wide application in photocatalysis, photovoltaics, gas sensing, lithium batteries, etc. One of the most important synthetic challenges is maintaining control over the polymorph composition of the prepared nanomaterial. In the present work, TiO2 NPs corresponding to anatase, rutile, or an anatase/rutile/brookite mixture were obtained at 80 °C by an inverse microemulsion method in a ternary system of water/cetyltrimethylammonium bromide/1-hexanol in a weight ratio of 17:28:55. The only synthesis variables were the preparation of the aqueous component and the nature of the Ti precursor (Ti(IV) ethoxide, isopropoxide, butoxide, or chloride). The materials were characterized with X-ray diffraction, scanning/transmission electron microscopy, N2 adsorption-desorption isotherms, FTIR and Raman vibrational spectroscopies, and diffuse reflectance spectroscopy. The synthesis products differed significantly not only in phase composition, but also in crystallinity, textural properties, and adsorption properties towards water. All TiO2 NPs were active in the photocatalytic decomposition of rhodamine B, a model dye pollutant of wastewater streams. The mixed-phase anatase/rutile/brookite nanopowders obtained from alkoxy precursors showed the best photocatalytic performance, comparable to or better than the P25 reference. The exceptionally high photoactivity was attributed to the advantageous electronic effects known to accompany multiphase titania composition, namely high specific surface area and strong surface hydration. Among the single-phase materials, anatase samples showed better photoactivity than rutile ones, and this effect was associated, primarily, with the much higher specific surface area of anatase photocatalysts.

One-Pot Synthesis of Cellulose-Based Carbon Aerogel Loaded with TiO2 and g-C3N4 and Its Photocatalytic Degradation of Rhodamine B.

A cellulose-based carbon aerogel (CTN) loaded with titanium dioxide (TiO2) and graphitic carbon nitride (g-C3N4) was prepared using sol-gel, freeze-drying, and high-temperature carbonization methods. The formation of the sol-gel was carried out through a one-pot method using refining papermaking pulp, tetrabutyl titanate, and urea as raw materials and hectorite as a cross-linking and reinforcing agent. Due to the cross-linking ability of hectorite, the carbonized aerogel maintained a porous structure and had a large specific surface area with low density (0.0209 g/cm3). The analysis of XRD, XPS, and Raman spectra revealed that the titanium dioxide (TiO2) and graphitic carbon nitride (g-C3N4) were uniformly distributed in the CTN, while TEM and SEM observations demonstrated the uniformly distributed three-dimensional porous structure of CTN. The photocatalytic activity of the CTN was determined according to its ability to degrade rhodamine B. The removal rate reached 89% under visible light after 120 min. In addition, the CTN was still stable after five reuse cycles. The proposed catalyst exhibits excellent photocatalytic performance under visible light conditions.

CeO2 nanospheres incorporated with Bi2MoO6/g-C3N4 enhanced photocatalysis towards environmental pollutant Rhodamine B removal.

We have adopted a novel CeO2/Bi2MoO6/g-C3N4-based ternary nanocomposite that was synthesized via hydrothermal technique. The physiochemical characterization of as-prepared samples was examined through various analytical techniques such as X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy TEM, photoluminescent spectra (PL), X-ray photoelectron spectroscopy (XPS), Brunauer-Emmett-Teller (BET), and ultraviolet diffuse reflectance spectroscopy (UV-DRS) technique. In addition, the photocatalytic performance was carried out by degradation of Rhodamine B dye under visible light irradiation using this nanocatalyst. The ternary nanocomposite achieved 94% of the degradation efficiency within 100 min which is higher than the pristine and binary composites under the predetermined condition pH = 7, Rhodamine B dye = 5 mg/L, and catalyst concentration = 150 mg/L. The experimental synergetic effect of CeO2/Bi2MoO6/g-C3N4 ternary nanocomposite has been ascribed to the interfacial charge carrier migration between CeO2, Bi2MoO6, and g-C3N4. The optical absorption range of CeO2/Bi2MoO6/g-C3N4 ternary nanocomposite was enhanced, and the band gap was reduced up to 2.2 eV. In addition, scavenger trapping experiment proves that the super oxide anions (O2-.) and photogenerated holes are the major active species. The reusability and stability experiment proved the CeO2/Bi2MoO6/g-C3N4 ternary nanocomposite keeps good durability during the photocatalytic degradation process after the five successive cycles. Furthermore, based on the results, the charge carrier transfer photocatalytic mechanism was also discussed. This CeO2/Bi2MoO6/g-C3N4 ternary nanocomposite may offer the cheapest material and extend the great opportunity for clean and environmental remediation approach under the visible light irradiation.

Fabrication of SrTiO3 anchored rGO/g-C3N4 photocatalyst for the removal of mixed dye from wastewater: dual photocatalytic mechanism.

A metal-free combination of rGO/g-C3N4-coupled SrTiO3 (SRN) ternary nanocomposite prepared via a wet impregnation method for UV-Vis light photocatalytic applications. Various physicochemical properties of the samples were investigated by several spectroscopic techniques including X-ray diffraction (XRD), FT-IR, Raman, field emission scanning electron microscopy with energy dispersive X-ray spectroscopy (FE-SEM-EDX), high-resolution transmission electron microscopy (HR-TEM), UV-Vis, photoluminescence (PL), X-ray photoelectron spectroscopy (XPS) and Brunauer-Emmett-Teller (BET) surface area analysis. The data suggest agglomerated SRT nanoparticles are dispersed and distributed throughout the surface of the rGO sheets and GCN nanostructures. The photocatalytic performance of the SRN towards combined mixed dye and its degradation activities were evaluated towards the most common industrial effluents, Rhodamine B (RhB) and Methylene blue (MB), under UV-Vis light illumination. The results revealed that the degradation efficiency of the SRN photocatalyst shows excellent performance compared with that of the binary composition and the pure SrTiO3 (SRT) sample. The reaction rate constant for RhB was estimated to be 0.0039 min-1 and for MB to be 0.0316 min-1, which are 3.26 (RhB) and 4.21 (MB) times faster than the pure SRT sample. The enhanced degradation efficiency was attained not only by interfacial formation but also by the speedy transportation of electrons across the heterojunction. After 5 runs of the photocatalytic recylic process, the SRN photocatalyst exhibited ultimate stability without structural changes, and no noticeable degradation was observed. The outcomes of the ternary SRN nanocomposite manifest a dual photocatalytic scheme, the photocatalytic enrichment could be caused by the Z-scheme charge transfer process between GCN, SRT, and rGO nanocomposite, which helps effectual charge separation and keeps a high redox potential. From the results, SRN sample provides insight into the integration of an effective and potential photocatalyst for wastewater treatment toward real-time environmental remediation applications.

Ultrasound-assisted advanced oxidation process using perovskite-type LaMnO3 nanospheres.

Among the perovskite oxide community, La-based perovskites have garnered considerable interest due to their remarkable properties including catalytic, electrocatalytic, photocatalytic, sensing, electrical, magnetic, and optical characteristics. Herein, rhodamine-B (RB) dye has been reported to be sono-catalytically decomposed by an ultrasound-assisted advanced oxidation process (AOP) using perovskite-type LaMnO3 (LMO) nanospheres synthesized via ultrasonic approach. Several physiochemical characterizations such as XRD, FT-IR, XPS, SEM, TEM, and SEM-EDS investigations were used to investigate the LMO perovskite nanospheres. Then, LMO potential for adsorption and the sonocatalytic decolorization of RB dye in an aqueous solution are examined. With LMO perovskites, the adsorption and removal kinetics of RB correspond to the pseudo-first-order model. Furthermore, by utilizing the pseudo-first-order, the RB dye process is removed with improved efficacy in the following sequence: Agitation alone: 3.76 x 10-4 min-1 <  US only: 5.02 x 10-3 min-1 < LMO only:  5.85 x 10-3 min-1 < LO@MO + US:  1.38 x 10-2 min-1 < LMO + US:  1.75 x 10-2 min-1, accordingly. Perovskite-type LMO, which has significant reusability and stability, is an ensuring sonocatalyst for dye decomposition in wastewater, enabling faster decolorization. A prospective mechanism has been suggested for the sonocatalytic decomposition of RB.

An Innovative Vortex-Assisted Liquid-Liquid Microextraction Approach Using Deep Eutectic Solvent: Application for the Spectrofluorometric Determination of Rhodamine B in Water, Food and Cosmetic Samples.

A new green and highly sensitive method for the determination of rhodamine B (RhB) by deep eutectic solvent-based vortex-assisted liquid-liquid microextraction with fluorescence detection (DES-VALLME-FLD) was developed. The extraction efficiency of conventional solvents and different deep eutectic solvent (DES) systems composed of tetrabutylammonium bromide (TBAB) and an alcohol (hexanol, octanol, or decanol) in different ratios were compared. DFT calculations of intermolecular electrostatic and non-covalent interactions of the most stable RhB forms with DES and water explain the experimental DESs' extraction efficiency. Semiempirical PM7 computations were used to obtain Hansen solubility parameters, which supported the good solubility of the monocationic RhB form in selected DESs. The dependence of the linear calibration of microextraction into 100 µL DES was observed in the RhB calibration range from 0.2 to 10.0 µg L-1 with a correlation coefficient of R2 = 0.9991. The LOD value was calculated to be 0.023 µg L-1. The accuracy and precision of the proposed method were verified over two days with RSD values of 2.9 to 4.1% and recovery of 94.6 to 103.7%. The developed method was applied to the determination of RhB in real samples (tap water, energy drink, and lipstick).