Rhodamine B Dye Research Articles

Infiltrated electroless deposition of gold nanoparticles on porous Prussian blue-Fe2O3 hetero-microstructures for environmental remediation applications: A novel infiltration strategy to form 3-D nano-catalytic networks

Metal and metal oxide nanocomposites are promising candidates for heterogeneous catalytic applications. In this regard, most of the metal oxide inner core volume remains as a dead volume, not participating in the catalysis, only the metal/metal oxide hetero-junctions available at the surfaces are involved in the catalysis. Herein, we report a novel strategy for the infiltration of gold nanoparticles into the inner core of 3D-porous Prussian blue/Fe2O3 hetero-microstructures (PBFHM-Au) beyond its outer surface to form an advanced heterogeneous catalyst for the environmental remediation applications. The porosity of the Prussian blue microstructures is thermally tuned for the infiltration of gold ion precursor into the inner core volume of Prussian blue/Fe2O3 hetero-microstructures to facilitate the galvanic displacement reaction between Fe and Au to enlarge the lattice shell and form Au nanoparticle 3D networks throughout the PBFHM. Notably, the resulting PBFHM-Au2 shows enhanced structural stability electron transfer kinetics and catalytic activity in comparison with the only surface-attached Au/Fe2O3 composite. The obtained PBFHM-Au2 catalyst demonstrates remarkable catalytic activity for Rhodamine-B dye degradation with rate constant (k = 3.47 × 10−2 s−1) and p-nitrophenol reduction reactions with rate constant (k = 1.199 × 10−1 s−1).

New recyclable and functionalized chitosan-based polyurethane foams for effective and incessant removal of Orange II (OII) and Rhodamine B (RhB) dyes from water

The development of new efficient materials for the removal of water-soluble toxic organic dyes has been one of the focused research areas in the recent past. There is a strong demand for the new materials as most of the reported techniques/materials suffer from serious limitations. In this regard, a series of flexible chitosan-based task-specific polyurethane foams (PUCS-GP, PUCS-CA-GP, PUCS-TA-GP, and PUCS-GA-GP) associated with naturally available hydroxycarboxylic acids was developed. The basis for the preparation of these task-specific and functionalized PU foams is to possess amine groups for trapping the anionic dyes (example: Orange II denoted as OII) and carboxylic acid groups for attracting the cationic dyes (example: Rhodamine B denoted as RhB) under specified pH conditions. Batch adsorption experiments were conducted to assess and improve various parametric conditions. The experimental results revealed that the adsorption kinetics closely agree with the pseudo-second-order model having a maximum sorption capacity of 38.3 mg/g at pH 3 for OII on PUCS-GP and 48.4 mg/g at pH 6 for RhB on PUCS-CA-GP. Furthermore, the adsorption process was described by isotherms, kinetic equations and thermodynamic parameters (ΔG°, ΔH° and ΔS°). Notably, the regeneration of OII and RhB dyes from the exhausted PUCS-GP and PUCS-CA-GP materials was effectively accomplished. The recovered PUCS-GP shows >90 % OII and PUCS-CA-GP displays >70 % RhB removal efficiency even after twelve adsorption–desorption processes under mild conditions, demonstrating excellent recyclability/durability. The advantages of these functionalized foam materials are facile preparation, high adsorption capacity, good reusability, and very efficient removal of organic dyes from wastewater streams.

Exploring structural and optical properties of iodine-doped TiO2 nanoparticles in Rhodamine-B dye degradation: Experimental and theoretical investigation

Energy conversion and pollutant degradation are critical for advancing sustainable technologies, yet they often encounter challenges related to charge recombination and efficiency limitations. This study explores iodine-doped TiO2 nanoparticles as a potential solution for enhancing both energy conversion and pollutant degradation. The nanoparticles were synthesized via the sol-gel method with varying iodine precursor concentrations (0.025–0.1 M) and were characterized for their structural, compositional, and optical properties, particularly in relation to their photocatalytic performance in Rhodamine-B dye degradation. X-ray diffraction confirmed a tetragonal anatase crystal structure, with the average crystallite size decreasing from 10.06 nm to 8.82 nm with increase in iodine concentration. Selected area electron diffraction patterns verified the polycrystalline nature of the nanoparticles. Dynamic light scattering analysis showed hydrodynamic radii ranging from 95 to 125 nm. Fourier-transform infrared spectroscopy identified metal-oxygen vibrations at 441 cm⁻1, and electron microscopy confirmed the spherical morphology of the nanoparticles. Elemental analysis detected the presence of Ti, O, and I in the samples. Diffuse reflectance spectroscopy indicated the optical absorption edges for the doped samples in the visible region from which the corresponding band gap values were deduced. Photoluminescence spectroscopy revealed that the sample with 0.1 M iodine exhibit the lowest emission intensity, suggesting reduced charge recombination. Notably, 0.1 M iodine doped TiO2 samples demonstrated the highest photocatalytic efficiency, achieving 82.36% degradation of Rhodamine-B dye within 140 min under visible light. Additionally, ab-initio density functional theory calculations were performed to investigate the structural, optical, and adsorption properties of TiO2, iodine-doped TiO2, Rhodamine-B, and their composites, providing further insight into the enhanced photocatalytic activity observed in the experiments.

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 1.34g, contact time of 71.59min, 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.

A highly efficient and stable PtNi bimetallic nanoparticles modified on Mo2C decorated N-doped carbon flowers catalysts for the remediation of environmental pollutants

The unregulated discharge of nitroaromatics (NAs) and organic dye contaminants into aquatic ecosystems is a growing global concern, highlighting the urgent need for the development of effective wastewater treatment technology. In this study, we prepared Mo2C decorated on N- doped carbon flowers supported with PtNi bimetallic (PtxNiy@Mo2C/NCF) nanoparticles using the self-polymerization of dopamine and followed by the chemical reduction methods. These catalysts, with varying Pt:Ni ratios, were designed for the highly efficient catalytic reduction of NAs and rhodamine b (RhB) under the mild reaction conditions. The HR-TEM images confirmed the formation of spherical PtNi bimetallic NPs with an average diameter of 1.68 ± 0.6 nm. The prepared PtxNiy@Mo2C/NCF catalysts exhibited significantly higher catalytic efficiency for 4-nitrophenol (4-NP) reduction compared to their respective monometallic counterparts using NaBH4. Particularly, the Pt0.75Ni0.25@Mo2C/NCF catalyst showed superior catalytic activity with the apparent rate constant (kapp: 0.6703 min−1) and TOF (17.0 × 10−7 mol mg−1 min−1) and high recyclability over eight consecutive recycles. Furthermore, the Pt0.75Ni0.25@Mo2C/NCF catalyst also exhibited high catalytic activity for other NAs and RhB dye reduction with excellent yields. This enhanced catalytic activity of Pt0.75Ni0.25@Mo2C/NCF catalyst could be ascribed to the synergistic effect of the bimetallic systems, leading to more efficient reactions. Additional experiments were conducted on a fixed bed reactor to demonstrate that the Pt0.75Ni0.25@Mo2C/NCF catalyst effectively reduce both 4-NP and RhB dye over 15 successive runs. This work may pave the way for using PtxNiy@Mo2C/NCF catalysts in various wastewater treatment applications.

Photocatalytic degradation of rhodamine B dye pollutants by Fe3O4/SiO2 core-shell magnetic nanocomposite functionalized with TiO2.

Significant efforts have been dedicated to creating recyclable and efficient methods for treating waste dyes, including rhodamine B (RhB). Nevertheless, challenges such as complex operational techniques, high costs, energy consumption, and inefficacy in dye removal persist. Here, the synthesis and application of TiO2/Fe3O4/SiO2 for photocatalytic degradation of RhB dye pollutants have been explored. This research was initiated with magnetite (Fe3O4) synthesis using the coprecipitation method, followed by silica (SiO2) extraction from rice husk waste using the sol-gel process, and a hydrothermal method for synthesizing titanium dioxide (TiO2) and TiO2/Fe3O4/SiO2 nanocomposite. The crystalline structure of TiO2/Fe3O4/SiO2 was obtained with Fe3O4 as the core, while TiO2 and SiO2 as the shell. The particle size analysis showed the nanosize of TiO2/Fe3O4/SiO2 (1.04 ± 0.46nm). TiO2/Fe3O4/SiO2 nanocomposite boasts a high surface area of 48.025 m2/g, 2.2 times higher than unmodified TiO2. This nanocomposite also displayed paramagnetic properties with a saturation magnetization of 9.117emu/g, facilitating easy separation in photocatalytic applications. The photocatalytic activity of TiO2/Fe3O4/SiO2 exhibited effectively degraded RhB, achieving a degradation rate of 53.58% and an excellent rate constant of 0.7303min-1. The RhB photodegradation in this study requires a moderate irradiation time (60min), uses only a tiny amount of photocatalyst (100mg), and does not need additional chemicals. Moreover, this study has another advantage of utilizing rice husk as a silica source, offering an eco-friendly and sustainable approach.

(Ce, Nd) co-doped TiO2 NPs via hydrothermal route:Structural, optical, photocatalytic and thermal behavior

Rare earth (Ce, Nd) doped/co-doped titania (TiO2) nanoparticles were successfully produced by hydrothermal route. Titanium isopropoxide (IV), cerium nitrate hexahydrate and neodymium nitrate hexahydrate were utilized as raw/starting materials. The effect of Ce and Nd doping/co-doping in TiO2 were studied through different complementary tools such as XRD, FTIR, FE-SEM, EDX, XPS, UV–Visible, PL, photocatalytic and thermal analysis. XRD spectra revealed anatase tetragonal phase and cubic phase due to titania and ceria nanoparticles respectively. The crystallite size, lattice constants, volume and no. of unit cell were determined through XRD data. Optical studies revealed the band gap, urbach energy, extinction coefficient, refractive index, optical conductivity and photoluminescence emission wavelength. FTIR spectra investigated the chemical bondings and functional groups present in prepared samples. Optical absorption spectra confirmed that absorption edge is red shifted, indicating a decrease in band gap from 3.5 to 3.0 eV with the incorporation of rare earth ions (Ce, Nd) in TiO2 matrix. The rate of electron-hole pair recombination was reduced through co-doping of (Ce, Nd) in TiO2 lattice as exhibited by reduction in intensity of photo luminescence spectra. The photocatalytic efficiency was enhanced with the integration of rare earth metal ions in TiO2 matrix for different dyes such as rhodamine B (RhB) and malachite green (MG) with visible light irradiation. The degradation efficiency of (Ce, Nd) co-doped TiO2 NPs against RhB and MG dyes was found to be 89 and 95 % respectively. TGA analysis was carried out to find weight loss during different thermodynamic phases such as dehydration, decomposition and combustion, and crystallization. Various thermodynamic parameters such as activation energy, entropy and enthalpy were estimated by thermal analysis.

Plant-based synthesis of Selenium-doped Silver/Magnesium Oxide/Zinc Oxide nanocomposite using Mentha pulegium to investigate their photocatalytic and biological properties

In this study, the photocatalytic test and biological effects of Selenium-doped Silver/ Magnesium Oxide/ Zinc Oxide nanocomposite (Se-doped Ag/MgO/ZnO) have been studied. The samples were synthesized by a green method with Mentha pulegium plant extract and investigated by different analyses. The outcomes of X-ray and FESEM display crystal nature and flower-like morphology. According to the ICP results, the removal efficiency of Pb+2 ions was equal to 72 %. The photocatalytic test of the nanocomposite investigated to degradation of organic dyes, and the results show that the degradation percentage of RhB (Rhodamine B), EBT (Eriochrome Black T), MO (Methyl Orange), and MB (Methylene Blue) dyes were about 73 %, 96 %, 99 %, and 97 % respectively. Also, the toxicity of the Se-doped Ag/MgO/ZnO) was studied against the cancer B16F0 cell line and the IC50 value was reported as 269.6 μg/mL.

Facile fabrication of carbon nanotubes/zinc oxide decorated poly(vinyl alcohol) electrospun nanofiber membrane and its photocatalytic performance

AbstractThe carbon nanotubes/zinc oxide (CNTs/ZnO) nanocomposites were immobilized on the poly(vinyl alcohol) (PVA) membrane for highly reutilization rate in photocatalytic degradation of RhodamineB (RhB) based on the combination of electrospinning and ultrasonication treatment. The results revealed that the CNTs are successfully compounded with ZnO, and the surface of nanofibers was uniformly covered with CNTs/ZnO nanoparticles. Under visible light irradiation, the CNTs/ZnO@PVA nanocomposites displayed excellent photocatalytic activity with 98.4% of RhB degradation rate within 3 h illumination. In comparison with pure PVA, and CNTs/ZnO with equivalent loading capacity on CNTs/ZnO@PVA film suspended in aqueous solution, the synthesized CNTs/ZnO@PVA film degrades RhB dye more efficiently. Furthermore, the photocatalytic activity of CNTs/ZnO@PVA nanocomposites did not change significantly even after five recycles, indicating a certain degree of reusability. The mechanism of enhanced photocatalytic activity was proposed. The as‐prepared flexible CNTs/ZnO@PVA nanocomposites could be employed as a promising material for the practical photocatalytic degradation of wastewater.

Ag nanoparticle functionalized vertical WS2 nanoflakes as SERS substrate for chemical sensing

Two-dimensional transition metal dichalcogenides (TMDCs) present a unique opportunity as Surface Enhanced Raman Scattering (SERS) substrates due to their superior optical properties. Here, vertically oriented tungsten disulfide (WS₂) flakes were synthesized on a silicon (Si) substrate using the pulsed laser deposition (PLD) technique. The WS₂ flakes were employed as SERS substrates for detecting low concentrations of environmental pollutants, like Rhodamine B (RhB) and Methyl Orange (MO) dyes, achieving promising enhancement factors of approximately 10⁷ with a 532 nm excitation laser. To further enhance the plasmonic activity of the vertical WS₂ flakes, silver nanoparticles (NPs) were decorated on their surface via thermal evaporation. The Ag NP-functionalized WS₂ flakes exhibited superior detection capabilities compared to pristine WS₂ flakes, achieving remarkable sensitivity at ultralow concentrations of 10⁻¹⁶ M for RhB and 10–17 M for MO dye, with enhancement factors of the order of 10⁸. The SERS performance of the WS₂-Ag substrate was also evaluated using a 633 nm laser, successfully detecting Methylene Blue (MB) dye at an ultralow concentration of 10⁻¹³ M. Prolonged exposure to RhB, MO, and MB dyes can cause cancer, neurotoxicity, and respiratory irritation. Thus, sensitive detection of these dyes at ultralow concentrations is highly crucial. A charge transfer mechanism between WS₂ and RhB dye molecules is proposed, along with the contribution of Ag NPs, to explain the enhanced detection capabilities of the nanocomposite SERS substrate.

Strongly tribocatalytic dye degradation of high-entropy powder through harvesting friction

The omnipresent friction can be harvested to generate electricity, thereby facilitating redox reactions to degrade dye wastewater, which can be named as tribocatalysis. Here, it’s experimentally found that the high-entropy CoCrFeMnNi powder synthesized via the Vacuum Induction Gas Atomization (VIGA) technique, can behave the obvious tribocatalytic Rhodamine B (RhB) dye degradation performance. In the tribocatalysis dye degradation process, friction occurs at the interface between the catalyst’s surface and the stirring Teflon rod. The tribocatalytic RhB dye degradation ratios of the high-entropy CoCrFeMnNi powder catalysts at stirring speeds of 200 rpm, 400 rpm, 800 rpm, 1000 rpm, and 1200 rpm are 14.7 %, 70.3 %, 93.2 %, 99.4 %, and 99.8 %, respectively. It’s also found that the RhB dye degradation ratio can be slightly enhanced under an external DC magnetic field provided by a commercial NdFeB magnet, which may be attributed to the magnetically-induced enhancement of separation efficiency of these positive and negative carriers. After being recycled for 3 times, the CoCrFeMnNi powder can still degrade 90.8 % RhB dye. The CoCrFeMnNi powder with the excellent tribocatalytic activity is potential for application in dye wastewater treatment through utilizing the friction energy in the environment.

Role of oxygen vacancy enriched m-BiVO4/t-BiVO4 isotype heterojunction for enhanced photocatalytic degradation of rhodamine B dye and in ferroelastic to paraelastic phase transition

Mixed-phase isotype heterojunction oxide materials with superior photocatalytic activities have recently revealed a significant coupling between individual phases with controlled optical properties. Therefore, we focus on synthesizing a mixed-phase monoclinic-tetragonal (m-t) BiVO4 photocatalyst using hydrothermal method. The increased recombination rate of electron-hole (e−-h+) pairs limits the photocatalytic performance of monoclinic (m) BiVO4 photocatalysts. Therefore, effective spatial charge carrier separation can be improved by creating an isotype heterojunction between the phases m-BiVO4 and t-BiVO4. The precursor pH, mechanical grinding, and calcination temperature regulate the formation of m-t BiVO4. The phase fractions of the two phases in m-t BiVO4 sample are 85% monoclinic and 15% tetragonal. Herein, we demonstrate the optical properties and photocatalytic activity based on the crystal chemistry of m-BiVO4 and m-t BiVO4. Temperature-dependent Raman measurements suggest a second order ferroelastic monoclinic to paraelastic tetragonal phase transition above 530 K owing to optical phonon anharmonic coupling interactions. The small increase (5 °C) in Tc in m-t BiVO4 compared to m-BiVO4 is due to the coexistence of tetragonal and monoclinic phases. The optical band gap of m-t BiVO4 is larger than that of m-BiVO4. Additionally, the evaluation of BiVO4 photocatalytic activity over rhodamine-B (Rh-B) dye suggests that the m-t BiVO4 with 97.5% degradation efficiency is superior compared to m-BiVO4 with 89% degradation efficiency. This is because, the two phases (m and t) of BiVO4 form an isotype heterojunction interface, which results in a high charge separation efficiency, as demonstrated by photocurrent studies and electrochemical impedance spectroscopy. Moreover, oxygen vacancies tune the charge carrier dynamics through the modification of band edges. These findings regarding the isotype phase-junction mechanism provide possibilities for innovative ideas for highly efficient mixed-phase isotype heterojunction photocatalysts for wastewater remediation.

Ultra-fast photocatalytic degradation of Rhodamine B exploiting oleate-stabilized zinc oxide nanoparticles

Rhodamine B (RhB) is a harmful dye released by industrial wastewaters, thus necessitating its urgent removal. Advanced oxidation processes constitute promising strategies to purify polluted water. Among others, photocatalysis relies on reactive oxygen species (ROS) produced by photocatalytic particles, typically semiconductors like titania or zinc oxide (ZnO), excited by solar or UV–Vis light. However, their wide band gap limits their catalytic capabilities within the absorption of the UV spectrum and causes fast electron–hole recombination. This study presents novel strategies to overcome these limitations: (i) doping semiconductors to increase photocatalytic efficiency; (ii) sensitization-mediated photocatalysis for visible light activation using chemical moieties to trap dye molecules; (iii) nanosizing the photocatalysts to enhance the surface area. ZnO nanoparticles, doped with iron or gadolinium and capped with oleic acid are here synthesized and tested in RhB dye solutions. Remarkably, the results demonstrate an ultra-fast RhB degradation, driven by oleic acid having crucial role in dye adsorption. The degradation mechanisms, including ROS-induced N-deethylation and xanthene group cleavage, are also unraveled. These findings underscore the efficacy of the proposed semiconductor photocatalyst design, highlighting a significant advancement with extensive potential applications in wastewater remediation. This innovative approach paves the way for more efficient and practical solutions to combat industrial dye pollution.Graphical abstract

Two new coordination polymers: crystal structures and photodegradation of the organic dye RhB

The solvothermal assemblies of a silicon-centered tetrahedral ligand as a principal building block, an N-donor ancillary ligand, and the corresponding metal salts yield two new transition metal coordination polymers (CPs), [Zn3(OH)(H2O)3L(ttb)]·3H2O (1) and [Co3(OH)(H2O)2L(ttb)(DMF)2]·2H2O (2) [H4L = 4,4',4'',4'''-silanetetrayltetrabenzoic acid, ttp = 1-(tetrazo-5-yl)-4-(triazo-1-yl)benzene, DMF = N,N-dimethylformamide]. Photocatalytic test results indicate that 1 and 2 can serve as excellent photocatalysts for Rhodamine B (RhB) degradation.

Efficient removal of Rhodamine-B dye using sulfonated/un-sulfonated three-dimensional mesoporous carbon nitride prepared from KIT-6 template: kinetics, modelling, thermodynamic analysis

Mesoporous carbon nitride (MCN-K) was prepared using mesoporous KIT-6 material as a template and ethylenediamine and carbon tetrachloride as N and C sources, respectively. The synthesized MCN-K was treated with sulfuric acid under different experimental conditions, thus obtaining sulfonated MCN-KS adsorbents. The effects of initial solution pH, initial dye concentration, adsorbent amount, and temperature on Rhodamine-B (Rh-B) dye removal were investigated. The XRD, FT-IR, and N2 adsorption–desorption analyses confirmed that the mesoporous carbon nitride structure was successfully synthesized. The high nitrogen content (C/N molar ratio: 4.0) of the MCN-K sample was confirmed by (carbon, hydrogen, nitrogen and sulfur) CHNS elemental analysis. The XPS analysis was used to characterize the chemical states of the C, N and S atoms in the MCN-K and MCN-KS sorbents. It was found that there was not much difference between the removal percentages (93.13–89.92%) obtained in the pH range (4–12) studied. This result was attributed to the zwitter-ion form of Rh-B. The exothermic nature of the adsorption process of Rh-B on the MCN-K sorbent was determined by adsorption experiments performed at different temperatures. Adsorption capacities obtained from the Langmuir model were 185.2–104.2 mg/g in the studied temperature range. The kinetic behavior of the adsorption process was explained by the pseudo-second-order kinetic model in terms of both correlation coefficients (R2 > 0.91) and qe (35.59–190.26 mg/g) values. When the percentages of dye removal of the un-sulfonated and sulfonated samples were compared, it was found that sulfonation increased the adsorption rate considerably but did not contribute positively to the dye removal percentage.

Green synthesized silver and zinc doped hydroxyapatite photocatalysts to remove methylene blue and Rhodamine B dyes from industrial wastewater

The present study focussed on the Scallop Sea shell waste utilized Hydroxyapatite and green synthesis of Canna indica leaf extracted Zinc (Zn) and Silver (Ag) doped Hydroxyapatite (HAp) formed by microwave irradiation method which is respectively represented as H, CIZH, and CIAH. The functional and structural characterizations (FTIR and XRD) of products confirm that the formed material was Hydroxyapatite due to the existence of characteristic absorption peaks and diffracted planes. The structural parameters such as average crystallite size, micro-strain (ε), dislocation density (δ), and particle size of the H, CIZH, and CIAH were calculated and the average Crystallite size are 42, 40, and 31nm. The morphology of the H, CIZH, and CIAH were assessed through FE-SEM and HR-TEM which could be majorly hexagonal-like (well distinct, and cluster of few rods). The EDAX spectrum and mapping confirmed the presence of chemical compositions of studied products. The anti-bacterial activities of studied products were assessed against Escherichia coli and Staphylococcus aureus, which exhibit good antibacterial activity. The photocatalytic activity of H, CIZH, and CIAH was examined against Methylene blue (MB) and Rhodamine B (RhB) dyes under UV light illumination. The degradation efficiency (%) of H, CIZH, and CIAH against MB and RhB dye were 58, 63, and 71%, and 58, 82 and 90%, respectively. A possible mechanism of the photocatalytic activity against the above-mentioned dyes is proposed. Thus, the present CIAH photocatalyst could be effective in degrading the wastewater.

Enhanced photocatalytic activity of Ag/ZnO nanocomposite immobilized on kanthal coils

Constructing hybrid semiconductor photocatalysts and increasing the charge-carrier density are effective strategies for enhancing the photocatalytic performance of ZnO. This study elucidates the synergistic effects of electron trapping and surface plasmon resonance (SPR) on the activity of ZnO photocatalysts. Ag/ZnO nanocomposites were synthesized on Kanthal coils using a two-step method involving the immobilization of ZnO on Kanthal coils and the coupling of Ag nanoparticles. XPS and RTPL analyses verified the synergistic effects of electron trapping and SPR on the activity of the Ag/ZnO nanocomposites. The photocatalytic performance of the composite was evaluated in the degradation of rhodamine B (RhB) dye. The Ag/ZnO nanocomposite exhibited significantly enhanced removal efficiency for RhB dye (38.2–70.5% depending on the deposition time). The Ohmic contact at the Ag/ZnO heterojunction extended the lifetime of the photoinduced charge carriers, whereas the SPR facilitated the generation of more electrons for the photocatalytic reaction. However, the excessive deposition of Ag nanoparticles compromised the photocatalytic performance of the Ag/ZnO nanocomposite. This study provides valuable insights for developing efficient ZnO-based photocatalytic materials for addressing environmental challenges.

Effect of CdS loading on the properties and photocatalytic activity of MoS2 nanosheets

Molybdenum sulfide (MoS2) and modified MoS2 with different percentages of CdS (10%, 30%, and 50% CdS@MoS2) were successfully synthesized and characterized. The photocatalytic performance of the MoS2 and CdS@MoS2 was evaluated by degrading brilliant green (BG), methylene blue (MB), and rhodamine B (RhB) dyes under visible light irradiation. Amongst the synthesized photocatalysts, 50% CdS@MoS2 exhibited the highest photocatalytic activity, degrading 97.6%, 90.3%, and 75.5% of BG, MB, and RhB dyes, respectively within 5 h. The active species involved in the degradation processes were investigated. All trapping agents inhibited BG and MB degradation to a similar extent, indicating that all of the probed active species play an important role in the degradation of BG and MB. In contrast, h+ and O2•− were found to be the main reactive species in the photocatalytic RhB degradation. A potential mechanism for the photocatalytic degradation of dyes using CdS@MoS2 has been proposed. This work highlights the potential of CdS@MoS2 as a photocatalyst for more efficient water remediation applications.

Preparation of CuFe2O4 via freeze-drying method and its application in boosting peroxymonosulfate activation to degrade rhodamine-B dye

Preparation of CuFe2O4 via freeze-drying method and its application in boosting peroxymonosulfate activation to degrade rhodamine-B dye

Synthesis of heterojunction BiVO4/MnO2 graphene ternary nanocomposites with enhanced photocatalytic activities through degradation of rhodamine B and tetracycline hydrochloride

Our research has resulted in synthesizing highly efficient BiVO4/MnO2 graphene ternary heterostructures prepared with a simple hydrothermal technique. These structures demonstrate exceptional performance in the photodegradation of rhodamine B (RhB) dye and tetracycline hydrochloride (TC). Adding MnO2 and graphene oxide significantly enhanced the absorption of visible light, photocatalytic activity, and surface area of the nanocatalyst. The prepared materials were characterized by XRD, SEM, BET, DRS, and PL spectroscopy. The PL spectra of G/MnBV-4 show less intensity and lower recombination rate, which is beneficial for photocatalytic activity. The as-synthesized G/MnBV-4 material exhibits outstanding photocatalytic activities toward the TC and RhB dye degradation under visible light irradiation. The reaction rate constant of G/MnBV-4 was estimated in the case of RhB and TC as 0.094 min−1 and 0.021 min−1 respectively, showcasing the material's high efficiency. The optimized material (BiVO4/MnO2 graphene) is stable and reusable, with only a 10 % reduction in removal efficiency after five consecutive cycles. Furthermore, the OH− and O2− are active species for removing organic pollutants. In contrast, holes are attributed to a lower effect. This study describes a photocatalytic approach to effectively removing the TC from waste bodies. The enhanced degradation efficiencies were ascribed to developing heterostructures and fast electron transfer between interfaces. Moreover, graphene increased photogenerated charge carriers' surface adsorption properties and charge separation efficiency. Hence, graphene works as an electron trapper and tuning bandgap energy, which plays a significant role in addition to photocatalytic activity.