Higher Degradation Rate Research Articles

Nano spray-dried particles of in-situ crosslinked alginate and their toxicological characterisation

The feasibility and technical capacity for producing crosslinked sub-micron gels with a nano spray-dryer were studied with variable pH systems incorporating alginate, pectin, and pullulan. The obtained powders were characterized for their morphology, particle size distribution, and their toxicological safety profile using genotoxicity and cytotoxicity assays. Additionally, quercetin was added to the encapsulation system to study the potential of the system to encapsulate this material. The produced powders exhibited morphologies and particle size distributions characteristic for nano spray-drying. The addition of pullulan and pectin to the feed solutions resulted in a particle size increase, with crosslinked alginate particles having a mean value of 1.43 μm, while particles with added pectin and pullulan had a mean particle size of 1.70 and 1.75 μm, respectively. The inclusion of quercetin proved to be problematic with this encapsulation system. Extremely high degradation rates and extremely low encapsulation efficiencies were observed due to the alkaline pH (~10) of the system that is needed to keep the feed dispersion in a liquid state and prevent premature crosslinking of the alginate. Although pectin and pullulan provided some protection for quercetin in the alkaline dispersion, the absolute quercetin content in the final product remained very low, with a maximum achieved encapsulation efficiency of 2.06 %. The safety profile of most produced powders was favourable, as they did not exhibit any significant cytotoxic and genotoxic activity in the HepG2 cell line, except in the case of Alginate/Pullulan which showed a 43 % decrease in cell viability at 500 μg/ml. Samples where quercetin was added did not show any increased toxicological effect.

Sustainable Photodegradation of Amoxicillin in Wastewater with a Nickel Aluminate and ZnO Heterosystem Oxides: Experimental and Gaussian Process Regression Modeling Studies

The wastewater generated by the pharmaceutical industry poses a risk to the environment due to undesirable characteristics such as low biodegradability, high levels of contaminants, and the presence of suspended solids, in addition to the high load of organic matter due to the presence of drugs and other emerging products in the effluent. This study aims to reduce the impact of wastewater pollution by removing amoxicillin (AMO) antibiotics as an organic pollutant. In this concept, two synthesized catalysts, NiAl2O4 and ZnO, are sensitive oxides to light energy. The prepared materials were then characterized using X-ray diffraction, UV–vis solid reflectance diffuse, Raman spectroscopy, scanning electron microscopy, BET, and ATR-FTIR spectroscopy. The effects of principal operating parameters under sunlight, namely, the percentage of the mixture of NiAl2O4 and ZnO, the pH of the medium, and the initial concentration of the antibiotic were studied experimentally to determine the optimal conditions for achieving a high degradation rate. The results showed that photodegradation is higher at a pH of 6, with a weight percentage of the mixture of 50% for both catalysts in 1 g/L of the total catalyst dose. Then, the effect of the initial concentration of AMO on the photodegradation reaction showed an important influence on the photodegradation process; as the degradation rate decreases, the initial AMO concentration increases. A high degradation rate of 92% was obtained for an initial AMO concentration of 10 mg/L and a pH of 6. The kinetic study of degradation established that the first-order model and the Langmuir–Hinshelwood (LH) mechanism fit the experimental data perfectly. The study showed the success of using heterosystem photocatalysts and sustainable energy for effective pharmaceutical removal, which can be extended to treat wastewater with other organic emerging pollutants. On the other hand, modeling was introduced using Gaussian process regression (GPR) to predict the degradation rate of AMO under sunlight in the presence of heterogeneous ZnO and NiAl2O4 systems. The model evaluation criteria of GPR in terms of statistical coefficients and errors show very interesting results and the performance of the model used. Where statistical coefficients were close to one (R = 0.9981), statistical errors were very small (RMSE = 0.1943 and MAE = 0.0518). The results suggest that the model has a strong predictive power and can be used to optimize the process of AMO removal from wastewater.

Fabrication and characterization of ZnO and Ag/ZnO nanoparticles for efficient degradation of crystal violet dye in aqueous solution

ZnO nanoparticles (ZnO NPs) were efficiently synthesized using three different methods: hydrothermal (ZnOhyd), solvothermal (ZnOsol), and co-precipitation (ZnOcop). The resulting ZnO NPs were further decorated with Ag NPs through photoreduction. All ZnO NPs and Ag/ZnO NPs were characterized by X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), Fourier transforms infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), nitrogen adsorption-desorption at −196 °C for porous structure analysis, UV–Visible spectroscopy, and photoluminescence (PL) measurements. The results confirmed that all ZnO NPs have a wurtzite hexagonal structure and that Ag NPs were successfully incorporated into the ZnO crystal lattice. The BET surface area of Ag/ZnOcop (150 m2/g) is much higher than that of undecorated ZnOcop (34 m2/g), confirming the successful incorporation of Ag nanoparticles. A redshift in the spectral absorption towards the visible light region and a reduction in the band gap, from 3.1 eV to 2.7 eV, was observed for the Ag/ZnOcop sample. The photocatalytic activities of ZnO NPs synthesized with different methods and Ag/ZnOcop NPs were assessed by their ability to degrade crystal violet (CV) in an aqueous solution when exposed to UV light. The Ag/ZnOcop sample had the highest degradation rate (95 %) than pure ZnOcop NPs (88.9 %). This degradation process relies on dye oxidation by highly reactive hydroxyl radicals, and several factors can affect its efficiency. The reduced PL intensity of Ag/ZnOcop compared to ZnOcop indicated that Ag NPs inhibit electron-hole recombination, enhancing photocatalytic activity by promoting charge separation.

Formation of Aromatic Halogenated Disinfection Byproducts in Swimming Pool Water during Chlorination: Organic Precursors and Mechanisms.

Disinfection byproducts (DBPs) in swimming pool water are a significant public health concern. The formation of aromatic halogenated DBPs in swimming pool water has not been clarified previously. In this study, the occurrence of aromatic halogenated DBPs in swimming pool water was examined, and it was found that halohydroxybenzoic acids (HBAs) and halobenzoquinones (HBQs) were the most dominant aromatic halogenated DBPs in swimming pool water that were continuously formed. Thus, the formation of HBAs and HBQs in swimming pool water from different organic precursors, including natural organic matter (NOM), pharmaceuticals and personal care products (PPCPs), during chlorination was examined. The results demonstrate that the formation of HBAs and HBQs from the PPCPs was relatively high compared with that from NOM, suggesting that the PPCPs from human inputs might be important organic precursors of aromatic halogenated DBPs in swimming pool water. The formation mechanisms of HBAs and HBQs from three typical PPCPs (benzophenone-3 (BP-3), methyl p-hydroxybenzoate (MeP) and carbamazepine) were further explored. The results show that the PPCPs containing phenolic groups with higher degradation rates (BP-3 and MeP) possessed higher formation of HBAs and HBQs. The three organic precursors underwent a series of substitution, hydrolysis, oxidation, rearrangement, and intramolecular cyclization reactions to form HBAs and HBQs, while the phenolic groups and ring structures may significantly affect the reactions. The chlorine dose, bromide/iodide concentration, and temperature significantly affected the formation of HBAs and HBQs from MeP during chlorination.

Novel cobalt-doped CuFe2O4 spinel catalyst for enhanced peroxymonosulfate activation to achieve rapid degradation of tetracycline hydrochloride: Dominant roles of O2[rad]- and 1O2 in the oxidation process

Heterogeneous peroxymonosulfate (PMS) catalysis is a promising method for water pollution treatment. CuFe2O4 spinel can activate PMS, but its application is limited by its tendency to agglomerate and its low-mass transfer efficiency. In this study, a cobalt-doped CuFe2O4 (CuFeCoO4, CFCo-1) was successfully synthesized, achieving a degradation efficiency of 98.36 % for tetracycline hydrochloride (TCH) within 21 min, with a high degradation rate corresponding to a kinetic constant of 0.2041 min−1. CFCo-1 demonstrated strong resistance to interference from inorganic ions and organic compounds. It maintained over 90 % TCH removal efficiency with negligible leaching of metal ions after five cycles, indicating that the catalyst had strong cyclic stability. Mechanistic analysis revealed that cobalt doping improved the electron transfer efficiency of the catalyst, enabling CFCo-1 to activate PMS and degrade the pollutant through both radical (OH, SO4- and O2-) and non-radical (1O2) pathways, with O2- and 1O2 being the dominant species. The potential degradation pathways of TCH were proposed based on theoretical calculation and the identification of degradation products. In conclusion, cobalt doping is an effective strategy for enhancing the catalytic performance of spinel for efficient degradation of pollutants in water.

TiO2/NiFe2-xCexO4/rGO ternary magnetic nanocomposite as separable and recyclable photocatalyst

This study investigates the synthesis and application of a TiO2/NiFe2-xCexO4/rGO ternary magnetic nanocomposite as an efficient and recyclable photocatalyst. The nanocomposite was characterized using Fourier-transform infrared(FTIR), X-ray diffraction(XRD), Field emission scanning electron microscopy(FE-SEM), magnetic measurements, UV–Vis diffuse reflectance spectroscopy(DRS), and X-ray photoelectron spectroscopy (XPS). FTIR analysis confirmed the formation of the inverse spinel cubic structure, with significant vibrational bands related to metal–oxygen complexes. XRD patterns showed successful incorporation of Ce3+ ions into the NiFe2O4 lattice, with shifts in diffraction peaks indicating changes in crystallite size and lattice parameters. FE-SEM images revealed a well-dispersed distribution of TiO2 and NiFe2O4 nanoparticles on the reduced graphene oxide (rGO) surface, enhancing the nanocomposite’s structural integrity. Energy dispersive X-ray(EDX) analysis demonstrated the presence of Ti, Ni, Fe, Ce, O, and C elements in the ternary nanocomposite without impurities, confirming the high purity of the material. Magnetic measurements indicated increased magnetization due to Ce3+ doping. DRS revealed optical band gaps (Bg), and XPS provided detailed insights into the surface chemical composition and valence states. XPS analysis confirmed the presence of Ni2+, Fe3+, Ti4+, and Ce3+ ions, and verified the reduction of graphene oxide to rGO. Importantly, the XPS data also indicated a reduction in the binding energy of oxygen species, which suggests effective electron trapping. The photocatalytic performance was assessed by the degradation of methylene blue (MB) under UV and Vis light. The TiO2/NiFe2-xCexO4/rGO nanocomposite demonstrated superior photocatalytic activity with high degradation rates. The enhanced photocatalytic efficiency is attributed to efficient electron trapping, which reduces electron-hole recombination. Furthermore, the nanocomposite showed excellent reusability, maintaining high photocatalytic efficiency over multiple cycles of use, which underscores its potential for practical applications in environmental remediation.

Enhanced Photocatalytic Degradation of Congo Red Dye Using Green-Synthesized TiO₂ and PANI/TiO₂ with Papaya Leaf as Bio-Reduction

This study uses the green synthesis method to investigate the photocatalytic properties of TiO2 nanoparticles (NPs) and PANI/TiO2 nanocomposites (NCs). The in-situ polymerization method used the papaya leaf extract as a reducing agent. TiO2 NPs have a particle size of 56 nm and a band gap of 2.46 eV, while PANI/TiO2 NCs have a particle size of 44 nm and a band gap of 2.06 eV. The performance of TiO2 NPs and PANI/TiO2 NCs as semiconductor-based photocatalysis was evaluated using Congo red dye degradation. The results showed that PANI/TiO2 NCs have better photocatalytic performance with a Congo red dye degradation rate of 97.12 %, higher than TiO2 nanoparticles (95.52 %). This enhanced performance can contribute to the synergistic effect between the TiO2 and PANI, leading to improved charge separation and reduced recombination. HIGHLIGHTS TiO2 nanoparticles made from green synthesis using papaya leaf bio-reduction. TiO2 has an anatase crystal structure, a particle size of 56 nm, and a band gap energy of 2.46 eV. PANI/TiO2 nanocomposites were synthesized using in-situ polymerization and had a particle size of 44 nm with a band gap energy of 2.06 eV. PANI/TiO2 NCs have a higher degradation rate towards Congo red dye than TiO2 GRAPHICAL ABSTRACT

Modulation of environmental dispersion due to ecological degradation in a two-zone width-dominated wetland flow

ABSTRACT Flow and environmental dispersion are necessary in water management systems. To better understand contaminant transport in wetland flows with adjacent aquatic vegetation and riparian buffers, a two-zone-model wetland is considered to characterize the water flow and environmental dispersion. Many researchers developed a dispersion model to characterize the mean concentration subject to the first-order degradation effect, present study attempts to derive an analytical dispersion model to discuss the transverse mean concentration of pollutants subject to second-order degradation effects in a width-dominated wetland flow. In addition, this study attempts to highlight the effect of environmental parameters like vegetation, viscous friction, and relative width on flow velocity. Also, the transverse mean concentration in the longitudinal direction is derived based on Mei’s multi-scale perturbation approach and analyzed with different degradation reaction rates. In a second-order reaction, higher degradation rate at a high concentration zone, contaminants degrade more effectively at the source than in a first-order reaction. It is conveyed that the pollutant transport is influenced by various parameters such as Peclet number, tortuosity, vegetation constraint, and dispersion time. For a specific water quality standard in wetlands, the maximal length and duration of the affected area for the common pollutant lead (Pb) is assessed and presented graphically; also, compared with a single zone.

Long-Term Stability of Nicotinamide Cofactors in Common Aqueous Buffers: Implications for Cell-Free Biocatalysis.

The use of nicotinamide cofactors in cell-free biocatalytic systems is necessitated by the high specificity that these enzymes show for their natural redox mediators. Unfortunately, isolation and use of natural cofactors is costly, which suggests that enhancing their stability is key to enabling their use in industrial processes. This study details NAD+ and NADH stability in three buffer systems (sodium phosphate, HEPES, and Tris) at 19 °C and 25 °C and for up to 43 d. In Tris, both NADH and NAD+ were found to be highly stable. NADH degradation rates of 4 μM/d (19 °C) and 11 μM/d (25 °C) were observed in Tris buffer, corresponding to >90% and 75% remaining after 43 d, respectively. Higher degradation rates (up to 34 μM/d) were observed when sodium phosphate or HEPES buffers were used. The effect of a mild increase in temperature was determined to be significant for long-term stability, and it was shown that degradation under these conditions can be easily monitored via UV-Vis, because the degradation proceeds via the oxidation/de-aromatization of the dihydropyridine ring. Overall, this work emphasizes that the choice of buffer system is consequential for bioreactor systems employing natural nicotinamide cofactors for extended periods of time.

Biosynthesis of gold and silver nanoparticle using water hyacinth (Eichhornia crassipes) extract for photocatalytic degradation of organophosphate and organochlorine pesticide

The study aimed to assess the efficiency of synthesized gold (Au) and silver (Ag) nanoparticles in the degradation of organochlorine and organophosphate pesticides through photocatalysis. The synthesis of gold and silver nanoparticles was achieved using Eichhornia crassipes (water hyacinth extract). Photocatalytic degradation tests were conducted on organochlorine and organophosphate pesticides using gold and silver nanoparticles, with the absorbance of the samples measured by a UV spectrophotometer. The photocatalytic degradation rates of organochlorine and organophosphate were determined, with varied concentrations of the synthesized nanoparticles. The results showed high degradation rates at lower concentrations (10–20 ppm), with degradations of 51.789%, 47.954%, 47.983%, 44.088%, 41.565%, and 36.749% for 25/75, 50/50, and 75/25 Au nanoparticle ratios, respectively. The results also revealed that higher degradation rates were observed at longer reaction times (70–80 minutes), with percentage degradations of 44.344% and 49.987%, 41.754% and 45.937%, 36.773% and 40.458% for 25/75, 50/50, and 75/25 Au nanoparticle ratios, respectively. Lower degradation efficiencies were observed at shorter reaction times (10–20 minutes), with percentage degradations of 15.356% and 19.982%, 13.746% and 17.082%, and 10.976% and 15.167% for 25/75, 50/50, and 75/25 ratios, respectively. Additionally, the results showed high degradation rates at lower concentrations (10–20 ppm) for Ag nanoparticles, with percentage degradations ranging from 40.814% to 44.822% across AgNP ratios (25/75, 50/50, 75/25), indicating efficient degradation at lower concentrations. Conversely, at higher concentrations (60–80 ppm), the degradation efficiency was notably lower, with percentage degradations ranging from 7.004% to 13.539% across different AgNP ratios. In conclusion, Au nanoparticles exhibited higher photocatalytic efficiency than Ag nanoparticles, particularly in degrading organophosphate (Sniper) pesticides. It is recommended that these synthesized nanoparticles be considered as environmentally friendly and cost-effective options for pesticide degradation.

IoT real-time monitoring system implemented to observe sunlight-influenced methylene blue degradation by AC/HAp.

Activated carbon (AC) and hydroxyapatite (HAp) composite were successfully prepared via mechanical mixing and exhibited a crushed snack-like morphology compared to the well-defined pore structure of pure AC. The purpose of this research was to explore the potential of AC/HAp for the degradation of methylene blue (MB) dye and hydrogen production. Despite the morphological changes, AC and AC/HAp achieved a high MB degradation rate (92.75 and 82.05) % under sunlight, at a temperature of 26.24°C and pH of 4.18, and showed optimum hydrogen production (3579mol/g.h). These performances are suspected from the decrease in crystallite size and narrowed and confirmed by image processing results with RBG enhancement showing more light transmitted by the solution. Increasing in indicates the potential for improved light interaction. IoT-enabled real-time monitoring system demonstrates its efficacy in facilitating wastewater treatment and hydrogen production, offering a promising solution for aquatic ecosystem restoration.

Revolutionizing pollution control with innovative CuO@TiO2 nanocomposite for enhanced photocatalytic degradation and antimicrobial efficacy

Facing the crisis of rising global pollution levels and the increasing threat of new pathogens, innovative and efficient strategies for degrading industrial waste and eliminating harmful pathogens are urgently needed. Therefore, we carefully designed and integrated CuO@TiO2 nanocomposite with a p-n heterojunction structure. Tests such as XRD, SEM, EDS and TEM showed that CuO was successfully and uniformly compounded on the surface of TiO2 to form nanoparticles with an average particle size of about 21 nm. Through carefully controlled experiments, we have demonstrated that these nanocomposites can degrade methylene blue by up to 83.90 % under irradiation with a xenon lamp, and maintain a relatively stable high degradation rate in repeatable photocatalytic tests, which highlights their great potential for pollution reduction. In addition, these nanocomposites also have a certain antibacterial effect. After 12 h of incubation in the dark, the bacterial survival rate was reduced to 94.07 %, and under light conditions, it was reduced to 92.35 %. It can be clearly seen under the microscope that the cell contents have leaked out and appear flocculent due to the rupture of the bacterial cells. These results are attributed to the synergistic effect of the release of Cu2+ and photocatalytic activity in the nanocomposite. This integrated approach positions CuO@TiO2 nanocomposite as a sustainable and cost-effective alternative to conventional antimicrobial agents and photocatalysts, paving the way for their wide application in environmental purification and microbial control.

Investigation of Bi2MoO6/MXene nanostructured composites for photodegradation and advanced energy storage applications

This study presents nanostructured composite Bi2MoO6/MXene heterostructure by using hydrothermal method for photodegradation of the congo-red dye and also for energy storage devices. X-ray diffractometer (XRD), High Resolution Transmission Electron Microscopy (HRTEM), Field emission scanning electron microscope (FESEM) and X-ray photoelectron spectroscopy (XPS), Brunauer-Emmett-Teller (BET) were performed to examine the structural properties along with surface area and porosity of the material. Due to addition of MXene the larger surface area and improved pore size help to quickly break down additional organic pollutants by adsorbing them. The band gap of Bi2MoO6/MXene nanostructured composite reduced to 2.4 eV suggesting transfer of electrons from VB to CB. Bi2MoO6/MXene exhibits a high (92.3%) photocatalytic degradation rate for a duration of 16 min which was verified using UV-visible spectroscopy, also scavenger test was conducted to ascertain the reactive agent along with the degradation pathway was confirmed by LCMS. Elemental content was also established by using inductively coupled plasma mass spectrometry (ICP-MS). For estimating energy storage capacity cyclic voltammetry (CV) was performed. It was observed Bi2MoO6/MXene nanostructured composite electrodes had specific capacitance of 642.91Fg− 1, power density of 1.24 kWkg− 1, and energy density of 22.32 Whkg− 1 at a current density of 5Ag− 1 also it exhibited 64.42% capacity retention having current density 20 Ag− 1 throughout 10,000 Galvanostatic charge discharge (GCD) cycles. High electrical conductivity of Bi2MoO6/MXene electrode was again examined by Electrochemical impedance spectroscopy (EIS). These findings demonstrate the potential of Bi2MoO6/MXene nanostructured composites in both photodegradation and energy storage applications.

Synbiotic Effects of Lacticaseibacillus paracasei K56 and Prebiotics on the Intestinal Microecology of Children with Obesity.

Lacticaseibacillus paracasei K56 (L. paracasei K56) is a probiotic with weight-loss effects. However, symbiosis research on the combined effects of Lacticaseibacillus paracasei K56 and prebiotics is lacking. Therefore, the aim of this study was to investigate the effects of L. paracasei K56, xylooligosaccharide (XOS), galactooligosaccharide (GOS), polyglucose (PG), and their synbiotic combinations (XOS + K56, GOS + K56, and PG + K56) on metabolism and gut composition in children with obesity, using an in vitro fermentation model. Fecal samples were collected from 14 children with obesity for in vitro fermentation, and the effects of the various treatments in gas production and short chain fatty acid synthesis (SCFAs) were assessed. Treatment with probiotics, prebiotics, and synbiotics regulated gut microbiota and metabolites in children with obesity. GOS and XOS had higher degradation rates than PG + K56 synbiotics in the gut microbiota of children with obesity. Moreover, treatment with XOS, GOS, and their synbiotic combinations, (XOS + K56) and (GOS + K56), significantly reduced the production of gas, propionic acid, and butyric acid compared with PG + K56 treatment. Treatments with GOS + K56 and XOS + K56 altered the composition of the gut microbiota, improved the abundance of Bifidobacteria and Lactobacilli, and reduced the abundance of Escherichia/Shigella. Overall, this study provides a theoretical foundation for the use of K56-based synbiotics.

Recyclable NiO/g-C3N4/ag hybrid substrates for sensitive SERS detection and photo-degradation of residual pesticides in beverages

In this research, we fabricated an innovative NiO/CN/Ag composite through the straightforward electrostatic assembly of Ag nanoparticles and g-C3N4 sheets onto NiO nanoflowers. This composite enables both surface enhanced Raman spectroscopy (SERS) detection and photo-degradation of pesticides. The results reveal NiO/CN/Ag can quantitatively detect thiram (TRM) and diquat dibromide (DQDB) in water, with a limit of detection (LOD) of 10−9 M, and also exhibit outstanding photo-degradation efficiency, exceeding 95 % for TRM and DQDB within 90 min under simulated sunlight. Significantly, after the organic reagent (citric acid) on NiO/CN/Ag was completely removed through simulated solar irradiation, the signal-to-noise ratios of SERS spectra on NiO/CN/Ag were enhanced, achieving LODs of 10−8 M for TRM and DQDB in different fruit juices and dried flower teas. Additionally, the composite demonstrate impressive recyclability, maintaining robust SERS signals and high degradation rates even after five cycles of “detection-degradation” processes.

Electrochemical Performances of a Solid Oxide Electrolysis Short Stack Under Multiple Steady-State and Cycling Operating Conditions

Solid oxide electrolysis cells (SOECs) are increasingly utilized in hydrogen production from renewable energy sources, yet high degradation rates and unclear degradation mechanisms remain significant barriers to their large-scale application. Consequently, endurance testing of stacks under various operating conditions and studying the degradation mechanisms associated with these conditions is imperative. However, due to the generally poor performance consistency among stacks, multi-condition data from numerous stacks lack reliability. In this experimental study, having established a specific SOEC stack’s performance and optimal conditions, durability tests under varied conditions, including various current densities, current operation modes (cyclic or constant current), fuel utilization rates, and temperature cycles were conducted. Electrochemical analysis tools like electrochemical impedance spectroscopy and distribution of relaxation time were employed to analyze the causes of voltage fluctuations under high current densities. The results confirmed that the SOEC stack could handle current cycling at low current densities and constant-current electrolysis at high current densities and withstand at least two temperature cycles.

Novel 3D plate-like g-C3N4/BiOCl heterojunction as a highly efficient photocatalyst for the degradation of carbofuran in wastewater under visible light irradiation

The g-C3N4/BiOCl (gCN-BCl) heterojunction photocatalyst was synthesized using a low-temperature precipitation method for effective photocatalytic degradation of carbofuran (CBF). All gCN-BCl composites demonstrate greater efficacy in removing CBF compared to its individual constituents. The synergistic effect of incorporating the 0D structured BiOCl onto the 2D structured g-C3N4 was comprehensively examined using various microscopic, X-ray, and spectroscopic analytical techniques. Additionally, optical and photoelectrochemical analyses were conducted. The findings validated that the interaction between the two semiconductors at the heterointerfaces enhanced remarkable physical and structural stability, promoted high charge separation and transfer properties, and improved photocatalytic degradation. Under optimal conditions, 5-gCN-BCl (0.25 g/L) achieved a CBF (5 mg/L) removal efficiency of 95.7 % under visible light irradiation of 120 min, achieving 3.1- and 5.9-times higher degradation rate than the pure BiOCl and g-C3N4, respectively. The radical trapping experiments indicated that the h+ and •O2− were the primary reactive species involved in the CBF degradation. Furthermore, the potential toxicity of CBF and its intermediates was assessed, revealing that the photocatalytic degradation process significantly lowered the ecotoxicity of pesticide wastewater. The potency of 5-gCN-BCl was also evaluated in tap water and real wastewater samples, with CBF degradation efficiencies of 85.8 %, 47.6 %, and 38.7 % in tap water, municipal, and pesticide industry wastewater, respectively. Additionally, artificial neural network (ANN) modeling was employed to predict and optimize the photocatalytic degradation process, providing further insights into the system’s performance. The outcomes of this work offer valuable insights into the development of heterojunction photocatalysts with superior stability and efficacy for eliminating pesticides from water bodies.

Synthesis and characterization of ZnO nanorods via hydrothermal route for wastewater recycling

In this work, highly efficient ZnO nanorods (NRs) were prepared using an easy and costeffective hydrothermal process. The Synthesized ZnO NR have been analyzed for their structure, morphology, and optical characteristics using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), Fourier Transform Infrared (FTIR), and ultraviolet-visible (UV-visible) spectroscopy, respectively. Additionally, a test is conducted on the ZnO nanorod's photocatalytic efficiency towards the degradation of certain dyes, Methylene Blue (MB) and Methyl Orange (MO). The FESEM investigation revealed that the ZnO nanostructures show nanorods with varying diameters (needle-like shape) with an estimated size of (10 to 20) µm. According to the XRD examination, the NRs had a hexagonal-shaped wurtzite pattern, exhibiting an average crystallite diameter of about 50 nm. FTIR spectra confirmed that functional groups from the substance being extracted were present in the ZnO NRs. The band-gap value of 3.37 eV was determined through the TAUC plot model from the ultraviolet-visible spectrum data. In the presence of as-synthesized ZnO NRs, the MO dye degraded by 100 percent in 46 minutes, but the MB dye significantly degraded by approximately 100 % in 20 minutes with high degradation rate constants kMO = 0.086 min-1 and kMB = 0.180 min-1, respectively.

Photocatalytic degradation of phenol and polycyclic aromatic hydrocarbons in water by novel acid soluble collagen-polyvinylpyrrolidone polymer embedded in Nitrogen-TiO2

The photocatalytic degradation of phenol, naphthalene, fluoranthene, phenanthrene, pyrene, benz[a]anthracene, and anthracene was investigated using a novel nitrogen-doped TiO2/acid-soluble collagen-polyvinyl pyrrolidone nanocomposite (N-TiO2/ASC-PVP). Characterization through X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) revealed that the nanocomposite consists of spheroidal particles smaller than those of undoped TiO2. X-ray photoelectron spectroscopy (XPS) confirmed the incorporation of nitrogen within the TiO2 lattice, appearing as both substitutional nitrogen (OTiN) and interstitial nitrogen (TiON). The degradation process followed apparent first-order kinetics, with the N-TiO2/ASC-PVP calcined at 200°C and 400°C demonstrating high photocatalytic degradation efficiencies. The nanocomposite achieved a remarkable 98.6% degradation of the targeted compounds within 120 minutes at a concentration of 10 mg/L. The enhanced photocatalytic activity under visible light can be attributed to several factors: the smaller crystal size, increased surface hydroxyl groups, improved visible light absorption, and a reduced band gap energy. This N-TiO2/ASC-PVP photocatalyst shows significant potential for applications in materials science and nanotechnology, supporting advancements in environmental and energy-related fields.

High-efficiency and stable Z-scheme heterojunction of Co9S8 anchored by g-C3N4 for peroxymonosulfate activation

Photocatalytic technology and peroxymonosulfate (PMS) based advanced oxidation technology have been proven to be simple and effective strategies for recalcitrant organic pollutants degradation. In this work, we designed and prepared a coupled photocatalytic and advanced oxidation system for sulfamethazine (SMR) antibiotics degradation. Firstly, a series of Z-scheme Co9S8/g-C3N4 heterojunction photocatalysts are prepared by a simple two-step method and further work as PMS activators. The prepared Co9S8/g-C3N4 photocatalysts exhibit a great improvement in electron-hole pairs migration and visible-light response due to heterojunction formation. In addition, the g-C3N4 acts as a substrate to anchor the Co9S8 nanoparticle, which suppresses the Co9S8 leaching and prevents the Co9S8 oxidation. Consequently, the Co9S8/g-C3N4/PMS system displayed an improved SMR degradation ability (93 % for Co9S8/g-C3N4/PMS vs. 86 % for Co9S8/g-C3N4). After the fourth cyclic degradation experiment, the Co9S8/g-C3N4/PMS system still maintained a comparatively high degradation rate. Considering its good properties and better degradation performance, we propose that the synergistic effect of photocatalytic technology and PMS possess a promising prospect for application in environmental treatment.