Novel Ag3PO4/boron-carbon-nitrogen photocatalyst for highly efficient degradation of organic pollutants under visible-light irradiation

Efficient degradation of organics by ultrasonic piezoelectric effect on CuO-BTO/AFC composite

The recombination of photoexcited electron-hole pairs greatly limits the degradation performance of photocatalysts. Ultrasonic cavitation and internal electric field induced by the piezoelectric effect are helpful for the separation of electron-hole pairs and degradation efficiency. The activated foam carbon (AFC) owing to its high surface area is often used as the substrate to grow catalysts to provide more reactive active sites. In this work, CuO@BaTiO3(CuO@BTO) heterostructure is prepared by hydrothermal method on the surface of AFC to investigate the ultrasonic piezoelectric catalysis effect. X-ray diffraction (XRD), Raman spectroscopy, energy dispersive x-ray spectroscopy (EDS) and scanning electron microscopy (SEM) were used to analyze the structure and morphology of CuO-BTO/AFC composite. It is found that the CuO-BTO/AFC composite exhibits excellent piezo-catalytic performance for the degradation of organics promoted by ultrasonic vibration. The CuO-BTO/AFC composite can decompose methyl orange and methylene blue with degradation efficiency as high as 93.9% and 97.6% within 25 min, respectively. The mechanism of piezoelectricity enhanced ultrasound supported catalysis effect of system CuO-BTO/AFC is discussed. The formed heterojunction structure between BTO and CuO promotes the separation of positive and negative charges caused by the piezoelectric effect.

Methyl esters synthesis from Luffa cylindrica seeds oil using green copper oxide nanoparticle catalyst in membrane reactor

This study investigates the potential role of Juglans sp. root extract-mediated copper oxide nanoparticles of Luffa cylindrica seed oil (LCSO) into methyl esters. The synthesized green nanoparticle was characterized by Energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FT-IR), and Scanning electron microscopy (SEM) spectroscopies to find out the crystalline size (40 nm), surface morphology (rod shape), particle size (80-85 nm), and chemical composition (Cu = 80.25% & O = 19.75%), accordingly. The optimized protocol for the transesterification reaction was adjusted as oil to methanol molar ratio (1:7), copper oxide nano-catalyst concentration (0.2 wt %), and temperature (90 °C) corresponding to the maximum methyl esters yield of 95%. The synthesized methyl esters were characterized by GC-MS, 1H NMR, 13C NMR, and FT-IR studies to know and identify the chemical composition of newly synthesized Lufa biodiesel. The fuel properties of Luffa cylindrica seed oil biofuel were checked and compared with the American Biodiesel standards (ASTM) (D6751-10). Finally, it is commendable to use biodiesel made from wild, uncultivated, and non-edible Lufa cylindrica to promote and adopt a cleaner and sustainable energy method. The acceptance and implementation of the green energy method may result in favourable environmental effects, which in turn may lead to better societal and economic development.

Synthesis, characterization and adsorption behavior of modified cellulose nanocrystals towards different cationic dyes

Green and efficient removal of polluted materials are essential for the sustainability of a clean and green environment. Nanomaterials, particularly cellulose nanocrystals (CNCs), are abundant in nature and can be extracted from various sources, including cotton, rice, wheat, and plants. CNCs are renewable biomass materials with a high concentration of polar functional groups. This study used succinic anhydride to modify the surface of native cellulose nanocrystals (NCNCs). Succinic anhydride has been frequently used in adhesives and sealant chemicals for a long time, and here, it is evaluated for dye removal performance. The morphology and modification of CNCs studied using FTIR, TGA & DTG, XRD, SEM, AFM, and TEM. The ability of modified cellulose nanocrystals (MCNCs) to adsorb cationic golden yellow dye and methylene blue dye was investigated. The MCNCs exhibited high adsorption affinity for the two different cationic dyes. The maximum adsorption efficiency of NCNCs and MCNCs towards the cationic dye was 0.009 and 0.156 wt%. The investigation for adhesive properties is based on the strength and toughness of MCNCs. MCNCs demonstrated improved tensile strength (2350 MPa) and modulus (13.9 MPa) using E-51 epoxy system and a curing agent compared to 3 wt% composites. This research lays the groundwork for environmentally friendly fabrication and consumption in the industrial sector.

The novel strategy of designing perovskite fiber membrane as reactor for catalytic oxidation

Negative impacts of wastewater contamination include harm to the environment, people, plants, and animals. Metal-based heterogeneous catalysts, particularly transition metal oxide catalysts, are a therapeutic option. However, they have limited reusability and cause secondary contaminations through metal leaching. In this work, a new membrane catalyst made of perovskite-type fiber was created and tested to remove methylene blue from wastewater. These innovative 3D perovskite ceramic catalysts work well in the breakdown of pollutants and dramatically lessen possible secondary contaminations caused by metal leaching from catalysts.

Hexagonal-borocarbonitride (h-BCN) based heterostructure photocatalyst for energy and environmental applications: A review

Formulation of heterojunction with remarkable high efficiency by utilizing solar light is promising to synchronously overcome energy and environmental crises. In this concern, hexagonal-borocarbonitride (h-BCN) based Z-schemes have proved potential candidates due to their spatially separated oxidation and reduction sites, robust light-harvesting ability, high charge pair migration and separation, and strong redox ability. H-BCN has emerged as a hotspot in the research field as a metal-free photocatalyst with a tunable bandgap range of 0-5.5 eV. The BCN photocatalyst displayed synergistic benefits of both graphene and boron nitride. Herein, the review demonstrates the current state-of-the-art in the Z-scheme photocatalytic application with a special emphasis on the predominant features of their photoactivity. Initially, fundamental aspects and various synthesis techniques are discussed, including thermal polymerization, template-assisted, and template-free methods. Afterward, the reaction mechanism of direct Z-scheme photocatalysts and indirect Z-scheme (all-solid-state) are highlighted. Moreover, the emerging Step-scheme (S-scheme) systems are briefly deliberated to understand the charge transfer pathway mechanism with an induced internal electric field. This review critically aims to comprehensively summarize the photo-redox applications of various h-BCN-based heterojunction photocatalysts including CO₂ photoreduction, H₂ evolution, and pollutants degradation. Finally, some challenges and future direction of h-BCN-based Z-scheme photocatalyst in environmental remediation are also proposed.

Synthesis and Application of Catalytic Materials in Energy and Environment

Catalytic materials have become prominent in many high-tech fields in recent years [...]

Editorial on the Topic "New Research on Detection and Removal of Emerging Pollutants"

With the Topic "New Research on Detection and Removal of Emerging Pollutants" (https://www [...].

Immobilization of photocatalytic materials for (waste)water treatment using 3D printing technology - advances and challenges

Photocatalysis has been considered a promising technology for the elimination of a wide range of pollutants in water. Various types of photocatalysts (i.e., homojunction, heterojunction, dual Z-scheme photocatalyst) have been developed in recent years to address the drawbacks of conventional photocatalysts, such as the large energy band gap and rapid recombination rate of photogenerated electrons and holes. However, there are still challenges in the design of photocatalytic reactors that limit their wider application for real (waste)water treatment, such as difficulties in their recovery and reuse from treated (waste)waters. 3D printing technologies have been introduced very recently for the immobilization of materials in novel photocatalytic reactor designs. The present review aims to summarize and discuss the advances and challenges in the application of various 3D printing technologies (i.e., stereolithography, inkjet printing, and direct ink writing) for the fabrication of stable photocatalytic materials for (waste)water treatment purposes. Furthermore, the limitations in the implementation of these technologies to design future generations of photocatalytic reactors have been critically discussed, and recommendations for future studies have been presented.

Facile preparation of visible light-sensitive layered g-C3N4 for photocatalytic removal of organic pollutants

The graphite-phase carbon nitride (g-C₃N₄) photocatalytic materials were prepared by one-step calcination method to degrade methylene blue (MB) and potassium butyl xanthate (PBX) under visible light irradiation. The prepared g-C₃N₄ photocatalytic materials were investigated in detail by various characterizations, and the experiments showed that the graphitic phase carbon nitride photocatalytic materials were successfully prepared by the one-step calcination method. The material possesses excellent optical properties and strong visible light absorption, thus achieving photocatalytic degradation of MB and PBX. The catalyst dosage, pH, the initial concentration of pollutants have important effects on photocatalytic activity of MB and PBX. The photocatalytic degradation efficiency was 98.99% for MB and 96.83% for PBX under the optimal conditions (catalyst dosage, initial pollutant concentration and pH value were 500 mg L^-1, 20 mg L^-1 and 7, respevtively). The photocatalytic mechanisms on MB and PBX were elucidated. ·OH was the key specie for MB, while ·O₂^- was the key specie for PBX. This study advances the development of photocatalytic technology for mineral wastewater.

Investigation on the evolution of hydrothermal biochar

The objective of this study was to visualize trends and current research status of hydrothermal biochar research through a bibliometric analysis by using CiteSpace software. The original article data were collected from the Web of Science core database published between 2009 and 2020. A visual analysis network of national co-authored, institutional co-authored and author co-authored articles was created, countries, institutions and authors were classified accordingly. By visualizing the cited literature and journal co-citation networks, the main subject distribution and core journals were identified respectively. By visualizing journal co-citations, the main research content was identified. Further the cluster analysis revealed the key research directions of knowledge structure. Keyword co-occurrence analysis and key occurrence analysis demonstrate current research hotspots and new research frontiers. Through the above analysis, the cooperation and contributions of hydrothermal biochar research at different levels, from researchers to institutions to countries to macro levels, were explored, the disciplinary areas of knowledge and major knowledge sources of hydrothermal biochar were discovered, and the development lineage, current status, hotspots and trends of hydrothermal biochar were clarified. The results obtained from the study can provide a reference for scholars to gain a deeper understanding of hydrothermal biochar.

Rational design of mixed ionic-electronic conducting membranes for oxygen transport

The mixed ionic-electronic conducting (MIEC) oxides have generated significant research efforts in the scientific community during the last 40 years. Since then, many MIEC compounds, most of which are based on perovskite oxides, have been synthesized and characterized. These compounds, when heated to high temperatures, form solid ceramic membranes with high oxygen ionic and electrical conductivity. The driving force for oxygen ion transport is the ionic transfer of oxygen from the air as a result of the differential partial pressure of oxygen across the membrane. Electronic and ionic transport in a range of MIEC materials has been studied using the defect theory, particularly when dopants are introduced to the compound of interest. As a result, many types of ionic oxygen transport limits exist, each with a distinct phase shift depending on the temperature and partial pressure of oxygen in use. In combination with theoretical principles, this work attempts to evaluate the research community's major and meaningful achievements in this subject throughout the preceding four decades.

Sedimentary environment and relative sea level changes revealed by marine biological membrane

Marine pollution has a deleterious impact, both on the conditions of the ecosystem and the biodiversity of the ocean. Researchers in the field of marine chemistry have been putting effort into the creation of efficient catalysts for the purification of seawater. There has been extensive research done on membrane technology for the activation of peroxymonosulfate, which is an extremely effective therapy for saltwater. The sediment of QX03, which was obtained from the western coast of Bohai, is located very close to the modern coastline. The uppermost 15 m of this sector were thoroughly analyzed in sedimentary petrology, grain size, shell, and sediment chroma dating to reconstruct the sedimentary environment and relative sea-level during the time period of 44.80 ka cal BP. This indicates that a sea-retreating and retreating process has taken place; VI (5.2-0 m), Terrestrial deposition, is separated into swamp wetlands (VI-1) and flood plain (VI-2). The changes in sedimentary levels had a fairly strong correlation with the changes in sea level. Within the scope of this study, we conducted an in-depth investigation of the innovative membrane technology for the treatment of seawater by means of aqueous phase advanced oxidation close to the Bohai. The results of this study present a prospective technique that could make it possible to use membrane technology in the process of environmental restoration in marine settings.

Heavy metals pollution characteristics and risk assessment in sediments and waters: The case of Tianjin, China

Potential health and ecological risks due to heavy metal pollution in surface waters and sediments were evaluated based on a health risk assessment model and a potential ecological risk index method. Combined with the reclamation progress of Tianjin Nangang Industrial Zone, in China, a survey was carried out in the area dealing with heavy metals concentrations in surface waters and sediments, covering from 2008 to 2018. Specifically, concentrations were determined for As, Cd, Hg, Cu, Pb, and Zn. The results show that As、Cd、Hg、Cu 、Pb、Zn average concentrations in surface water were 0.99 μg/L∼1.27 μg/L, 0.13 μg/L∼0.63 μg/L, 0.03 μg/L∼0.13 μg/L, 1.5 μg/L∼4.65 μg/L, 1.25 μg/L∼4.7 μg/L, 13.5 μg/L∼20.99 μg/L and which average concentrations in sediment were 5.12 mg/kg∼12.34 mg/kg, 0.12 mg/kg∼0.18 mg/kg, 0.04 mg/kg ∼0.087 mg/kg, 13.45 mg/kg∼31.92 mg/kg, 13.2 mg/kg ∼21.26 mg/kg, 21.58 mg/kg ∼77.21 mg/kg, respectively. The background values of the Hailuan River basin near the study area were taken as the reference and compared with the national sediment quality standards a tell us the quality of the sediments in Tianjin Nangang coastal area being good. As regards the characteristics of pollution, heavy metals showed a high concentration in 2008 and then decreased significantly, which related to the dredging of large amounts of contaminated surface sediment during port construction. According to the phase equilibrium partition coefficient (Kp) and temporal and spatial distribution characteristics of heavy metals, sediments can be seen as an obvious sink for lead, with this element being mainly affected by exogenous input in coastal seawater. Zn, As, Cd, and Hg contents in surface water were greatly affected by the endogenous release from sediments. The results of the environmental risk assessment showed that the main environmental health risk of Tianjin coastal waters was carcinogenic, and specifically due to As. The potential heavy metals ecological risk assessment results of surface sediments were mild for the affected areas.

Arsenite (III) removal via manganese-decoration on cellulose nanocrystal -grafted polyethyleneimine nanocomposite

The manganese is successfully induced as a "bridge joint" to fabricate a new adsorbent (CNC-Mn-PEI) connecting cellulose nanocrystal (CNC) and polyethyleneimine (PEI) respectively. It was used to remove As (III) from waste water. It has been proved that the incompact CNC and PEI were successfully connected by Mn ions, which induced the formation of O-Mn-O bonds and the removal efficiency is maintained in the broad pH range of 4-8, even with the influence of NO₃^- and CO₃^2-. The CNC-Mn-PEI was characterized by Brunauer-Emmett-Telley (BET) method and the results showed that the nanoparticle of the specific surface area was 106.5753 m²/g, it has a significant improvement, compared with CNC-Mn-DW (0.1918 m²/g). The isotherm and kinetic parameters of arsenic removal on CNC-Mn-PEI were well-fitted by the Langmuir and pseudo-second-order models. The maximum adsorption capacities toward As (III) was 78.02 mg/g. After seven regeneration cycles, the removal of As (III) by the adsorbent decreased from 80.78% to 68.2%. Additionally, the hypothetical adsorption mechanism of "bridge joint" effect was established by FTIR and XPS, which provided the three activated sites from CNC-Mn-PEI can improve the arsenic removal efficiency, and providing a new stratagem for the arsenic pollution treatment.

New trends on green energy and environmental technologies, with special focus on biomass valorization, water and waste recycling: editorial of the special issue

In this editorial piece, the Editors of the Virtual Special Issue (VSI) "New Trends on Green Energy and Environmental Technologies, with Special Focus on Biomass Valorization, Water and Waste Recycling", present summarized data corresponding to the accepted submissions, as well as additional comments regarding the thematic of the VSI. Overall, 83 manuscripts were received, with final publication of those having the highest quality, accepted after peer-reviewing. The Editors think that the result is a set of very interesting papers that increase the knowledge on the matter, and which would be useful for researchers and the whole society.

Photocatalytic degradation of amoxicillin and tetracycline by template synthesized nano-structured Ce3+@TiO2 thin film catalyst

Contamination of the aquatic environment with pharmaceutical compounds is a serious environmental concern. The present investigation aims to utilize the Ce³⁺/TiO₂ thin film catalyst to remove of potential antibiotics (amoxicillin and tetracycline) using the less harmful UV-A radiations. Reduced cerium ion-doped TiO₂ is obtained by a simple one-step facile template method using polyethylene glycol as the templating agent. The synthesized catalysts Ce³⁺@TiO₂ (non-template) and Ce³⁺@TiO₂(T) (template) were characterized by spectroscopic methods. The XPS reaffirms the reduced Ce³⁺ dispersed within the titania network, and the AFM showed the surface roughness of the thin films. Detailed physicochemical analyses were conducted to deduce the degradation mechanism, and repeated use of the thin film photocatalyst showed enhanced stability. Significant mineralization of the antibiotics indicates the potential applicability of the photocatalytic catalyst. Furthermore, the presence of Ce³⁺ significantly restricted the recombination of electron/hole pairs in the photo-excited TiO₂ semiconductor and showed enhanced photocatalytic degradation of the antibiotics proceeded predominantly through the •OH.

Application of Raney Al-Ni Alloy for Simple Hydrodehalogenation of Diclofenac and Other Halogenated Biocidal Contaminants in Alkaline Aqueous Solution under Ambient Conditions

Raney Al-Ni contains 62% of Ni₂Al₃ and 38% NiAl₃ crystalline phases. Its applicability has been studied within an effective hydrodehalogenation of hardly biodegradable anti-inflammatory drug diclofenac in model aqueous concentrates and, subsequently, even in real hospital wastewater with the aim of transforming them into easily biodegradable products. In model aqueous solution, complete hydrodechlorination of 2 mM aqueous diclofenac solution (0.59 g L⁻¹) yielding the 2-anilinophenylacetate was achieved in less than 50 min at room temperature and ambient pressure using only 9.7 g L⁻¹ of KOH and 1.65 g L⁻¹ of Raney Al-Ni alloy. The dissolving of Al during the hydrodehalogenation process is accompanied by complete consumption of NiAl₃ crystalline phase and partial depletion of Ni₂Al₃. A comparison of the hydrodehalogenation ability of a mixture of diclofenac and other widely used halogenated aromatic or heterocyclic biocides in model aqueous solution using Al-Ni was performed to verify the high hydrodehalogenation activity for each of the used halogenated contaminants. Remarkably, the robustness of Al-Ni-based hydrodehalogenation was demonstrated even for the removal of non-biodegradable diclofenac in real hospital wastewater with high chloride and nitrate content. After removal of the insoluble part of the Al-Ni for subsequent hydrometallurgical recycling, the low quantity of residual Ni was removed together with insoluble Al(OH)₃ obtained after neutralization of aqueous filtrate by filtration.

Potentially toxic elements in cascade dams-influenced river originated from Tibetan Plateau

Rivers originated from Tibetan Plateau are of great significance due to their environmental sensibility and fragility. However, the pollution of suspended particulate matter (SPM) in these rivers is rarely reported, in particular, the potentially toxic elements (PTEs) contamination. To clarify the status, sources, behavior, and risks of PTEs in SPM, a full investigation was conducted in dams-influenced Lancangjiang River basin. The findings revealed that the PTEs content (mg kg^-1) ranked Mn (766) > V (151.7) > Zn (131.0) > Cr (94.6) > Ni (44.2) > Pb (36.7) > Cu (29.4) > Co (14.6) > Sb (2.6) > Mo (1.6) > Tl (0.78) > Cd (0.48). The multi-index assessment suggested that Sb and Cd were moderately severe to severe enriched PTEs with the enrichment factor values of 10.0 and 8.8 and the geo-accumulation index values of 2.2 and 2.0, respectively, while the rest of PTEs were minor/no enrichment. In contrast, Cr and Ni were major toxic elements in SPM which contributed 25 ± 10%, 24 ± 8% to the total toxic risk index. The high partition coefficients (e.g., 6.1 for Cr) were observed in most PTEs and resulted in the 96.3% of Cr, 85.2% of Zn, 83.6% of Pb, 77.8% of Ni, and 63.2% of Cu transportation in the SPM form. Natural inputs (e.g., soil erosion) are the main source (53.6%∼61.9%) of V, Cr, Mn, Co, Ni, and Tl, while fuel burning contributed 40.9% of Zn, 32.5% of Pb, and 37.3% of Cd. Moreover, 51.2% of Sb was attributed to industrial waste source, while porphyry copper/molybdenum deposits related milltailings were the co-source of Mo (54.4%) and Cu (34.8%). Overall, the PTEs geochemistry of SPM showed the potential in tracing regional environmental change.

Pt/Pd Decorate MOFs Derived Co-N-C Materials as High-Performance Catalysts for Oxygen Reduction Reaction

We report here, a strategy to prepare Pt/Pd nanoparticles decorated with Co-N-C materials, where Co-N-C was obtained via pyrolysis of ZIF-67 directly. As-prepared Pt/Pd/Co-N-C catalysts showed excellent ORR performance, offered with a higher limit current density (6.6 mA cm−2) and similar half-wave potential positive (E1/2 = 0.84 V) compared with commercial Pt/C. In addition to an ORR activity, it also exhibits robust durability. The current density of Pt/Pd/Co-N-C decreased by only 9% after adding methanol, and a 10% current density loss was obtained after continuous testing at 36,000 s.

Perovskite oxide for emerging photo(electro)catalysis in energy and environment

Using solar energy to catalyse photo-driven processes to address the energy crisis and environmental pollution plays a role in the path to a sustainable society. Many oxide-based materials, especially perovskite oxides, have been widely investigated as catalysts for photocatalysis in energy and environment because of the low-cost and earth-abundant and good performance. At this stage, there is a need to present a scientific-based evaluation of the technologies developed so far and identify the most sustainable technologies and the existing limitations and opportunities for their commercialisation. This work comprehensively investigated the outcomes using various scientometric indices on perovskite oxide-based photo(electro)catalysts for water splitting, nitrogen fixation, carbon dioxide conversion, organic pollutant degradation, current trends and advances in the field. According to the results achieved, efforts in both energy and environment based on perovskite oxides have been initiated in the 1990s and accelerated since the 2010s. China and the United States were identified as the most contributing countries. Based on the results achieved in this study, the main milestones and current trends in the development of this field have been identified. The aim of this research is to provide useful guidelines for the further investigation of perovskite oxide-based catalysts for photoelectrocatalysis and photocatalysis both in energy and environment on the applications such as water splitting, nitrogen fixation, carbon dioxide conversion, and wastewater treatment.

Efficient Visible-Light-Responsive Ag3PO4/g-C3N4/Hydroxyapatite Photocatalyst (from Oyster Shells) for the Degradation of Methylene Blue: Preparation, Properties and Mechanism

A novel ternary Ag3PO4/g-C3N4/hydroxyapatite photocatalyst was prepared, and its morphology, composition and structure were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, high-resolution transmission electron microscopy, and electron spin resonance, etc. The results show that g-C3N4 is evenly dispersed in the interior of hydroxyapatite, forming a homogeneous composite, and significantly improves the band gap structure of the material as a whole. Ag3PO4/g-C3N4/hydroxyapatite has good electron transfer ability and an appropriate energy band structure, which shows that the material has a good degradation effect and stability. Finally, based on the characterization and experimental results, a possible Z-scheme mechanism was proposed, and the active species involved in the reaction are mainly O2− and h+.

Elimination of amoxicillin using zeolite Y-sea salt as a good catalyst for activation of hydrogen peroxide: Investigating degradation pathway and the effect of wastewater chemistry

The sea contains elements that can play a useful role in catalyzing reactions. Therefore, this research was done to focus on eliminating amoxicillin (AMX) from wastewater utilizing zeolite Y- sea salt catalyst in the presence of H₂O₂. The influences of furnace temperature (200-500 °C) and time duration in the furnace (1-4 h) were optimized during catalyst generation. Also, the effects of different parameters on AMX removal, such as pH (5.0-9.0), catalyst dose (0-10 g.L^-1), AMX concentration (50-300 mg.L^-1), contact time (10-130 min), and H₂O₂ concentration (0-6 mL/100 mL distilled water) were investigated. Different analyses like Brunauer-Emmett-Teller (BET), Fourier transform infrared (FTIR), X-ray diffraction (XRD), and thermogravimetric analysis (TGA) were conducted to reveal catalyst properties. The BET-specific surface area of the catalyst (12.69 m²g^-1) insignificantly (p-value > 0.05) changed after AMX removal (13.04 m²g^-1), indicating the strength of the prepared catalyst. The active groups of N-H, O-H-O, O-Si-O, C-H, Si-O-Si, and Si-O-Al were determined in the catalyst structure. The highest removal of AMX (93%) was achieved in the zeolite-sea salt/H₂O₂ system at a pH level of 6.0 and an H₂O₂ concentration of 0.1 mL/100 mL. Elimination of the AMX followed pseudo-first-order kinetics. The catalyst was reclaimed up to 7 times and the removal efficiency was suitable up to the fifth stage. The by-products and reaction pathways were investigated by gas chromatography-mass spectrometry (GC-MS). The results showed that zeolite-sea salt can be utilized as an H₂O₂ activator for the effective degradation of AMX from wastewater.

TiO2/g-C3N4 photocatalyst for the purification of potassium butyl xanthate in mineral processing wastewater

In the present work, TiO₂-graphite-phase-carbon-nitride (TiO₂/g-C₃N₄) was prepared through a hydrothermal method to obtain a new photocatalytic material. This material was characterized by means of scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray energy spectrometer (EDS), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FT-IR), Solid-state UV-Vis diffuse reflectance spectrometry (UV-Vis-DRS) and electron paramagnetic resonance (EPR). The synthesized TiO₂/g-C₃N₄ exhibited homogeneous morphology, in which TiO₂ nanoparticles were uniformly distributed on the g-C₃N₄ nanosheets. Regarding its potential use as photocatalytic material in the treatment of mineral processing wastewater, 18% TiO₂/g-C₃N₄ showed superior photodegradation performance than TiO₂ and g-C₃N₄, to give 97.1% degradation rate under 100 min of simulated light irradiation. The experimental results showed that the successful incorporation of TiO₂ on g-C₃N₄ nanosheets enhanced the spectral response range of TiO₂/g-C₃N₄, and the photocatalytic activity was improved. In view of that, it can be considered that this kind of photocatalytic material has a good prospect in the treatment of mineral processing wastewater, which would have clearly environmental relevance.

Highly efficient photo-degradation of cetirizine antihistamine with TiO2-SiO2 photocatalyst under ultraviolet irradiation

Photocatalysis is an extraordinary and vastly researched topic; there is a need to find new ways to support producing composite materials that are cost-effective, efficient and have a low environmental impact. The investigation was undertaken on syn TiO2 by depositing it on silica. The results elucidate the positive effect on photocatalysis activity and the macroscopic structure on which the TiO2 is formed. For the analysis of photocatalyst, various characterisation measurements were undertaken, such as XRD, FTIR, DRS, FESEM, TEM, RS, and BET. The accumulated TiO2 onto the surface of SiO2 stabilised its transformation of the phase from anatase to rutile, resulting in decreased particle size and enhancing its photocatalytic activity under UV irradiation. The concentration of OH• radicals was determined using terephthalic acid as a probe molecule to determine its role in the photocatalytic degradation of antihistamine. The results of BET analysis showed that the syn TiO2-SiO2 sample has a large specific surface area of 192.6 m2 g−1. Maximum degradation of cetirizine (about 97%) was achieved with 80% TiO2-20% SiO2 (TS-4). Recyclability test confirmed that 80% TiO2-20% SiO2 sample was stable up to six cycles.