The advancement of efficient photo catalytic materials for environmental applications has become a rapidly growing area of research in recent years. This study emphasizes the photodegradation of Methyl Orange (MO), an anionic dye, under natural solar light using an innovative heterogeneous Ag@Co₃O₄/g-C₃N₄ catalyst synthesized via a green method using Syzygium cumini leaf extract. A comprehensive set of characterization techniques, were employed to investigate the crystal structure, surface morphology, functional groups, elemental composition, and optical properties of the synthesized material. The BET analysis indicated that the nanocomposite possessed a surface area of 68.4 m²/g, while the energy band gap, determined from Tauc’s plot, was approximately 2.25 eV. The photo catalytic performance was investigated by MO dye degradation with changing factors such as dye solution pH, dye concentration, catalyst dose, and irradiation period. Within 60 min, the catalyst attained a maximum degradation efficiency of 99

Perovskite oxide photocatalysts exhibit significant potential for solar-driven wastewater remediation; however, their moderate band gaps and rapid charge recombination limit their practical efficiency. In this study, Fe-doped lanthanum cobaltite perovskites (LaCo1-xFexO3; x = 0.05 and 0.07, denoted as LCFO-5 and LCFO-7) were synthesized via a citrate-assisted sol-gel auto-combustion method and evaluated for the photocatalytic degradation of crystal violet (CV), a persistent and genotoxic triphenylmethane dye, under simulated solar irradiation. Rietveld-refined X-ray diffraction (XRD) analysis confirmed a single-phase rhombohedral structure (R-3c) without detectable secondary phases, indicating successful substitutional incorporation of Fe3+ at Co3+ sites. UV-Vis diffuse reflectance spectroscopy revealed progressive band gap narrowing from 2.1 eV (pristine LCO) to 1.9 eV (LCFO-5) and 1.7 eV (LCFO-7). Despite the lower band gap of LCFO-7, LCFO-5 exhibited superior photocatalytic performance, highlighting the importance of an optimal balance between light absorption and charge carrier recombination. FESEM and BET analyses indicated a mesoporous structure with a surface area of 64.27 m2 g-1 and an average pore diameter of 3.83 nm, facilitating enhanced adsorption and catalytic activity. Under optimized conditions (40 ppm CV, 60 mg catalyst, pH 9, 80 min irradiation), LCFO-5 achieved 96.7

The increasing discharge of organic pollutants, including dyes and pharmaceuticals, into water bodies poses a severe environmental threat. Industrial activities alone contribute to 17–20% of global water pollution through the release of untreated dye effluents. Recent advancements demonstrate that biochar-reinforced metal oxide photocatalysts (BSPs) enhanced efficiency for pollutant degradation, achieving removal rates up to 99.2% for dyes like methylene blue and 94% for pharmaceuticals such as malachite green under visible-light irradiation. However, challenges remain in scaling up BSP applications due to inconsistent feedstock properties, poor stability, and limited regeneration capacity. This review identifies these critical gaps and provides a comparative analysis of BSP compositions, synthesis methods, and photocatalytic efficiencies. Furthermore, it recommends future studies to focus on optimizing pyrolysis parameters, designing multifunctional composites to improve charge separation, and integrating BSPs into solar-driven reactor systems for sustainable treatment solutions. The review also advocates for comprehensive ecotoxicity and life-cycle assessments prior to field deployment.

This research aimed to explore a novel and straightforward precipitation-based synthesis method for fabricating a NiO/ SrFe12O19 p-n heterojunction nanocomposite photocatalyst. Several characterization techniques were employed for evaluating the materials' properties: FTIR for functional groups, SEM for morphology, EDX for elemental composition, UV-DRS for bandgap energy, and EIS for charge transfer resistance, PL for recombination studies, XPS for surface chemical states, and XRD for crystalline phases. This work investigated the photocatalytic activity and reusability of the nanocomposite for the removal of rhodamine B (RhB) (cationic) dye and ibuprofen drug under solar light irradiation. To determine the ideal photodegradation conditions, intrinsic reaction parameters such as catalyst loading, solution pH, and beginning pollutant concentration and agitation of time were investigated. A binary NiO/SrFe12O19 catalyst with a 0.60 mg loading at pH 3.5 destroyed 93% of 60ppm RhB dye after 100 min of solar light irradiation. Furthermore, for ibuprofen degradation, at pH 7, catalyst dose 0.75 mg, pollutant concentration 10 ppm, and irradiation time 120 min, the composite showed 75% removal efficiency under solar light. Moreover, this composite catalyst demonstrated exceptional chemical stability and reusability, removing 60% of the RhB dye and 41% of ibuprofen after four recycling runs.Scavenger tests demonstrated that photogenerated holes (h+) and superoxide free radicals (·O2) are the primary reactive species causing degradation. This study gives information on the creation of highly effective nanomaterials for removing dyes from wastewater, as well as a possible reaction mechanism.

Reactive Blue-222 (RB-222) is resistant to biodegradation because of its complex molecular structure and high chemical stability, so conventional wastewater treatment is largely ineffective at removing it. In this study, a NiCo2O4/ZIF-8 nanocomposite was fabricated via a ZIF-67-templated synthesis of NiCo2O4 nanorods followed by in-situ growth of ZIF-8. This structural design aims to address limitations in light absorption, charge recombination, and surface accessibility. Structural and surface characterization (XRD, FTIR, FE-SEM/EDX, XPS and BET) indicates the successful integration of spinel NiCo2O4 with the porous ZIF-8 framework, resulting in approximately six-fold increase in surface area (377.86 m2 g− 1) compared to pristine NiCo2O4. Optical analysis revealed enhanced visible-light absorption with an effective bandgap of 1.88 eV for the composite. Under natural visible light irradiation, the optimized 10 wt

Polluted water harms human health and the planet's wellbeing alike. Tackling the global energy crisis driven by rapid economic expansion and our reliance on power hungry gadgets demands innovative clean energy storage solutions. This study developed a ternary heterojunction photocatalyst based on g-C₃N₄/TiO₂/MWCNTs studied their structural, optical, and morphological properties, the produced materials were thoroughly evaluated via XRD, FTIR, BET, UV-Vis DRS, PL, SEM, TEM, Raman, and XPS studies. The photocatalytic activity of the g-C₃N₄/TiO₂/MWCNTs nanocomposite was evaluated via the degradation of rhodamine B dye under solar light with various parameters, and the results revealed that the g-C₃N₄/TiO₂/MWCNTs nanocomposite had 99% degradation efficiency with Z scheme mechanism and outperformed the pristine g-C₃N₄ sheet and TiO₂, with approximately 1.3 and 1.4 folds higher degradation rates, respectively. The photodegradation process was followed by pseudo first-order kinetics with a rate constant of 0.0922 min⁻¹, resulting in a 2.36 and 3.16 fold increase compared to pristine catalysts. The HR-MS and scavenger test results suggested that intermediates formed and that photoinduced radicals play important roles in the photodegradation process. Electrochemical impedance spectroscopy revealed improved electrical conductivity, and cyclic voltammetry investigations revealed an outstanding specific capacitance of 1860 F/g at 30 mV/s nearly six times greater than that of pristine g-C₃N₄ (348 F/g).The remarkable photocatalytic performance and good electrochemical properties of the g-C₃N₄/TiO₂/MWCNTs heterojunction highlight its promise as a multifunctional material for environmental purification and energy storage applications.

A ternary photocatalyst, Bi2O3/g-C3N4/NiMnO3, was synthesized via simple calcination, where NiMnO3 incorporation into the Bi2O3/g-C3N4 matrix formed a dual S-scheme heterojunction with g-C3N4 acting as an electron mediator between Bi2O3 and NiMnO3. This configuration enhanced charge transfer, promoted electron-hole separation, and improved redox activity, as confirmed by structural, morphological, and optical characterization. The Bi2O3/g-C3N4/NiMnO3 composite exhibited significantly improved photocatalytic activity toward the degradation of mixed organic dyes, cationic crystal violet (CV) and anionic Congo red (CR), under natural solar light irradiation. The optimized catalyst achieved approximately 99% degradation of crystal violet (CV), 94% of Congo red (CR), and 92% degradation of mixed dyes within 90 min under ambient conditions, using 40 mg of catalyst in 40 mL of dye solution at standard temperature and pressure. The pH values were adjusted to pH 7 for crystal violet (CV), pH 3 for Congo red (CR), and pH 6 for the mixed dye solution, based on the optimal stability and adsorption behaviour of the respective dyes in aqueous media. The photocatalytic degradation followed pseudo-first-order kinetics (R2 = 0.98) for the mixed dye, indicating efficient and reproducible reaction behaviour. Photoluminescence (PL) spectra confirmed the suppressed recombination of photo-induced charge carriers, consistent with the proposed dual S-scheme charge transfer mechanism. Radical scavenging identified (OH)-O-center dot and (center dot)O2- as key reactive species, and the photocatalyst retained good stability and reusability after four cycles. Electrochemical analysis verified efficient charge transport and stable semiconducting behaviour.

The development of sustainable and efficient photocatalysts for solar-driven wastewater treatment remains a critical challenge. In this work, a green-synthesized magnetically retrievable NiFe2O4/La-ZnO heterojunction nanocomposite was fabricated using Syzygium aromaticum (clove) extract as a biogenic fuel and complexing agent. Structural and surface analyses confirmed the formation of a well-coupled spinel-wurtzite heterointerface with La-induced lattice modulation. UV-visible diffuse reflectance spectroscopy revealed a narrowed band gap of 1.64 eV, while electrochemical impedance analysis indicated reduced charge-transfer resistance and suppressed carrier recombination. Under natural sunlight irradiation, the optimized NFO/La–ZnO (1:1) composite achieved 97 % degradation of Eosin Yellow (20 ppm) within 100 min, outperforming pristine counterparts. Scavenger and kinetic studies identified superoxide (•O2⁻) and hydroxyl radicals (•OH) as the dominant reactive species governing the degradation process. The photocatalyst exhibited excellent magnetic recoverability and stable performance over repeated cycles. This study demonstrates a sustainable heterostructure design strategy integrating green synthesis, band-gap engineering, and magnetic recyclability for efficient solar photocatalytic water remediation.

The development of efficient photocatalysts for wastewater treatment is crucial for mitigating organic pollution. In this work, a Sr-doped Bi4Ti3O12/Co3O4 S-scheme heterojunction was synthesized via a facile solid-state and precipitation method and evaluated for the solar-light-driven photodegradation of crystal violet (CV) dye. X-ray diffraction (XRD) confirmed the orthorhombic phase of Bi4Ti3O12 with successful Sr incorporation along with spinel Co3O4. FTIR spectra displayed characteristic metal oxygen vibrations, validating composite formation. UVDRS analysis revealed extended solar light absorption with a significantly reduced band gap of 1.6 eV compared to pristine Bi4Ti3O12 (2.8 eV). Photoluminescence studies showed suppressed charge recombination, indicating efficient charge carrier separation. Under solar -light irradiation, the Sr-doped Bi4Ti3O12/Co3O4 composite achieved ∼95% degradation of CV within 55 min, following pseudo-first-order kinetics (k = 0.035 min-1). Furthermore, the photocatalyst exhibited excellent stability and reusability over multiple cycles. These findings highlight the synergistic role of Sr doping and S-scheme heterojunction formation in enhancing photocatalytic performance, offering a promising pathway for the design of advanced materials for wastewater remediation.

In this study, a Sr-doped BiVO4/g-C3N4 (Sr@BiVO4/g-C3N4) heterojunction photocatalyst was successfully synthesized through a facile hydrothermal-assisted thermal treatment route. X-ray diffraction (XRD) analysis confirmed the successful incorporation of Sr2+ ions into the BiVO4 lattice, resulting in slight lattice distortion and improved crystallinity. Fourier-transform infrared (FTIR) and UV-Vis diffuse reflectance spectroscopy (DRS) analyses revealed strong interfacial coupling between BiVO4 and g-C3N4, along with a noticeable red shift in the absorption edge, leading to a reduced band gap of 2.17 eV. The synergistic effect of Sr doping and heterojunction formation significantly enhanced charge separation efficiency. The optimized Sr-BiVO4/g-C3N4 photocatalyst exhibited remarkable photocatalytic performance, achieving up to 99

The discovery and development of efficient photocatalytic materials for environmental applications is a rapidly evolving research area. This work addresses the photo degradation of RhB 6 G, a fluorescent dye, utilizing a novel heterogeneous catalyst: lanthanide metal-doped Co₃O₄. Pristine Co₃O₄ was produced using chemical sol-gel and green synthesis with Azadirachta indica leaves (Neem leaf) extract. The catalysts’ structural, morphological, and optical characteristics were investigated using XRD, FT-IR, FE-SEM, HR-TEM, UV-DRS, RAMAN, BET, XPS, and PL analysis. The average diameters of the crystallites were found to be 11.47 nm (Ce-doped), 41 nm (green), and 45 nm (chemical). Based on Tauc plots, the corresponding band gap energies were 2.42 eV, 2.8 eV, and 2.9 eV, respectively. The Ce@Co₃O₄ catalyst’s surface area increased significantly, according to the BET study (96.2 m²/g), and PL analysis revealed lower emission intensity, which suggests suppressed charge carrier recombination. Additionally, XRD-based microstructural analysis revealed that Ce@Co₃O₄ exhibited the highest dislocation density and microstrain, suggesting a higher density of structural defects that may facilitate more efficient charge separation and enhanced surface reactivity. The degradation of RhB 6G under direct sunlight irradiation was used to determine photo-catalytic activity. Various parameters, such as reaction conditions, reactive species identification, mechanism, and the effects of competing species, were investigated. After 75 min of exposure to sunlight, the doped catalyst degraded by an astonishing 94

Water pollution caused by dye discharge is a critical environmental concern, driving the exploration of efficient wastewater treatment methods using nanocomposites. This study presents the synthesis of a CoO/BiVO4 nanocomposite, with CoO and BiVO4 prepared through the co-precipitation process. The structural, morphological and optical properties of the synthesized catalyst were characterized using XRD, FESEM and UV-DRS analyses. The band gap energies, determined from Tauc’s plot, were found to be 2.9 eV for pristine BiVO4 and 2.5 eV for the CoO/BiVO4 nanocomposite, indicating enhanced light absorption. The photocatalytic performance of the nanocomposite was evaluated by degrading malachite green dye under solar irradiation. Various parameters, including pH, catalyst dosage, dye concentration and irradiation time, were optimized to maximize degradation efficiency. The nanocomposite achieved 84% dye degradation at pH ~ 7 using 40 mg of catalyst on a 40 ppm dye solution within 80 min of solar exposure. Kinetic analysis revealed that the degradation followed a pseudo-first-order kinetic model. Moreover, the reusability of the catalyst was confirmed, showing stable performance even after five consecutive cycles. The findings highlight the potential of the CoO/BiVO4 nanocomposite as a sustainable photocatalyst for effective dye degradation in wastewater treatment applications under solar light.

: During the past few decades, great efforts have been devoted to developing non-toxic, low-cost, green and studied photocatalysts for the degradation of toxic dyes from surface water with the aid of sustainable, plentiful, and renewable solar light irradiation. Perovskite oxides with a wide range of applications, including photocatalytic water decontamination possess unique properties that make them suitable for performing efficiently in visible spectrum and facilitate catalytic reactions. This mini-review specifically specializes in double/layered perovskites and their associated materials and summarizes the recent improvement of double/layered perovskite photocatalysts and their packages in the degradation of organic dyes.

Nanomaterials with advanced functionalities offer immense potential for environmental remediation by accelerating pollutant degradation and promoting sustainable purification methods. This study presents the synthesis of lanthanide cerium (Ce)-doped BiVO₄ via a cost-effective co-precipitation approach, followed by a comprehensive evaluation of its structural, morphological, and optical characteristics. X-ray diffraction (XRD) analysis confirmed the monoclinic phase of BiVO₄. The calculated average crystallite sizes for pristine and Ce-doped BiVO₄ were 51.3 nm and 43 nm, respectively, indicating a reduction due to Ce incorporation. Fourier Transform Infrared (FTIR) spectroscopy further validated the successful doping through noticeable peak shifts in the vibrational spectra. The surface morphology and elemental composition of the synthesized catalysts were analyzed using Field Emission Scanning Electron Microscopy (FESEM) and Energy Dispersive X-ray (EDX) spectroscopy.The optical properties, examined through UV-Vis Diffuse Reflectance Spectroscopy (UV-DRS), exhibited a redshift in the absorption edge, enhancing visible light responsiveness. Tauc’s plot analysis demonstrated a reduction in band gap energy from 2.54 eV (pristine) to 2.3 eV (Ce-doped BiVO₄), indicating improved light-harvesting efficiency. Photoluminescence (PL) spectroscopy revealed suppressed charge carrier recombination, both contributing to superior photocatalytic performance. The photocatalytic activity was assessed by degrading Methylene Blue (MB), a model cationic dye, under varying experimental conditions. The Ce-doped BiVO₄ exhibited an exceptional degradation efficiency of 98 A simple low cost co-precipitation method was used for synthesis of Ce doped BiVO4. The catalyst showed 98

The reported work presents the facile synthesis of modified Bi4Ti3O12 photocatalyst for the degradation of a type-II toxic dye malachite green (MG) assisted by a renewable source i.e. solar light irradiation. Various weight percentages of Strontium (2, 3 and 4) were doped with Bi4Ti3O12 by a sol-gel method (ionic radii of Sr2 + and Bi3+ are nearly same). The structural and morphological characteristics, chemical composition, surface area, and optical properties were investigated by FT-IR spectroscopy, X-ray diffraction (XRD), Field Emission Scanning Electron Microscopy-Energy Dispersive Spectroscopy (FE-SEM-EDS), and UV-Vis diffuse reflectance spectroscopy (DRS), and photoluminescence (PL) analysis, HR-TEM and BET analyses. The characterization reported the crystalline phases of Sr-Bi4Ti3O12 to be orthorhombic with bandgap energy of 2.61 eV highly active in visible spectrum. The photocatalytic degradation of MG with Sr-Bi4Ti3O12 was carried out with changing parameters such as catalyst dose, pH, initial dye concentration and time. The results showed highest photocatalytic degradation of 87 % by (3) Sr-Bi4Ti3O12 towards MG, where the initial concentration was 40 ppm at pH value = 8 in 60 min at a catalyst dose of 20 mg. whereas under similar conditions pristine BTO exhibited only 47 % degradation. Furthermore, the photocatalyst demonstrated higher chemical stability and reusability as similar to 85 % of the MG dye was degraded after five consecutive runs. The kinetic studies reported the MG degradation by Sr-Bi4Ti3O12 followed a pseudo-1st order rate. The role of active species participation was carried out with Na-EDTA, BQ and IPA revealed that the photogenerated holes (h(+)) and superoxide free radicals (O-center dot(2)-) were the principal reactive species responsible for degradation.

Ibuprofen is a potential environmental toxin and carcinogen for freshwater ecosystems, posing significant risks to human health, particularly through its impact on kidney function. This research introduced a new type of bismuth ferrite perovskite material, modified with separable lanthanum, to explore how sunlight can be used to break down ibuprofen in water. The catalysts used in the study were created through green synthesis and co-precipitation methods, and their characteristics were analyzed using various techniques like X-ray diffractometry (XRD), Field Scanning emission microscopy (FE-SEM), X-ray photoelectron spectroscopy (XPS), UV–VIS absorption spectroscopy (UV-DRS) and Photoluminescence spectra (PL). The green-synthesized 1

The topic of wastewater remediation has been extensively discussed in recent years, and one of the main pollutants has been dyes. One of the promising techniques for dye degradation is photocatalysis. A novel transition metal Fe with different percentage (15%, 20%, 25%) doped Co3O4 was prepared employing a novel green process using Mangifera Indica leaf extract.The structural, morphological, optical, and electrical properties of doped catalyst was studied by XRD, FTIR, FE-SEM, HR-TEM, PL, CV, EIS, TGA, XPS, UV-DRS, and BET analysis.By doping the Fe metal on the surface of Co3O4 resulting increase in surface area with improving charge carriers separation and lower the band gap energy. The photocatalytic activity was studied by degrading BG dye under solar light.25% Fe doped cobalt oxide having band gap energy 2.1 eV showed maximum degradation efficiency of 96% at pH 8 on 30 ppm dye concentration with 30 mg catalyst under 90min.The radical trapping experiment showed the vital role of hydroxyl and superoxide radical in degradation mechanism. By doping Fe atoms the efficiency of the host is increased which will be the most promising candidate for the photocatalytic dye degradation applications. The material presents a strong possibility for use in super capacitor applications due to its increased current density and lower on set potential.

Water pollution from untreated dye discharge has become a significant concern for all living organisms and the treatment of polluted water has become a priority. In this study, a monoclinic–tetragonal hetero-structured BiVO4 and strontium doped (15, 20 and 25 wt.%) BiVO4 NPs were synthesized using a simple co-precipitation method. The structural, optical and morphological properties of the catalysts were characterized using XRD, FTIR, UV-DRS, FESEM, TEM, PL and BET analysis. The XRD pattern exhibited the retentions of crystalline structure of BiVO4 after Sr doping. The Sr-BiVO4 exhibited a reduced band gap energy of 2.3 eV, significantly lower than that of the pristine BiVO4. Additionally, Sr-BiVO4 had an increased surface area of 16.2 m2/g nearly twice that of the pristine material. Photocatalytic activities of the prepared samples were evaluated with changing parameters such as pH, initial concentration, catalyst dose and agitation time towards the degradation of methylene blue (MB) and malachite green (MG) dyes under solar light irradiation. The results showed that Sr-BiVO4 achieved a degradation efficiency of 91% for methylene blue and 94% for malachite green at pH ~ 9 with a 20 mg catalyst dose in 120 min. The dye degradation followed a pseudo-first-order kinetic model and the catalyst demonstrated an excellent stability even after five consecutive runs. The active species test carried out using p-benzoquinone, isopropyl alcohol and Na-EDTA revealed that superoxide radicals played a key role in the degradation mechanism.

In this work, we synthesised a new Ce-doped Co₃O₄/BiVO₄ heterojunction photocatalyst by a green synthesis strategy utilizing Magnifera indica leaf extract for Co₃O₄ and a precipitation method for pure BiVO₄. X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), UV-Visible diffuse reflectance spectroscopy (UV-DRS), Brunauer-Emmett-Teller (BET) surface area analysis, field emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), and cyclic voltammetry (CV) were used to investigate the material's structural, optical The Ce-Co₃O₄/BiVO₄ heterojunction decreased the band gap energy to 1.92 eV, resulting in increased visible light absorption. The photocatalytic activity of the developed heterojunction was evaluated by degrading the anionic dye Congo red (CR) under different circumstances such as pH, catalyst dose, dye concentration, and irradiation period. At pH 4, 98% degradation was obtained using a dye concentration of 50 ppm, a catalyst dose of 40 mg, and 50 minutes of sun light exposure. High-resolution mass spectrometry (HR-MS) validated the effective degradation of CR and offered information on the potential degradation process. Kinetic investigations revealed that the photodegradation of CR followed a pseudo-first-order kinetic model. This study demonstrates the effectiveness of Ce-Co₃O₄/BiVO₄ heterojunctions in photocatalytic applications, namely for the removal of dye contaminants from wastewater using visible light. Furthermore, the heterojunction showed a substantial rise in specific capacitance, reaching 1353 F/g, 5.4 times that of pure Co3O4. The Nyquist plot displayed a smaller arc radius, indicating improved electrochemical characteristics and a possible application as a semiconductor. These results highlight the Ce-Co₃O₄/BiVO₄ heterojunction as a promising photocatalyst with outstanding dye degrading capabilities and increased electrochemical performance, appropriate for diverse environmental and energy storage applications.