Toxic Heavy Metal Ions Research Articles

4-[(E)-2-(1-Pyrenyl)Vinyl]Pyridine Complexes: How to Modulate the Toxicity of Heavy Metal Ions to Target Microbial Infections.

Pyrene derivatives are regularly proposed for use in biochemistry as dyes due to their photochemical characteristics. Their antibacterial properties are, however, much less well understood. New complexes based on 4-[(E)-2-(1-pyrenyl)vinyl]pyridine (PyPe) have been synthesized with metal ions that are known to possess antimicrobial properties, such as zinc(II), cadmium(II), and mercury(II). The metal ion salts, free ligand, combinations thereof, and the coordination compounds themselves were tested for their antibacterial properties through microdilution assays. We found that the ligand is able to modulate the antibacterial properties of transition metal ions, depending on the complex stability, the distance between the ligand and the metal ions, and the metal ions themselves. The coordination by the ligand weakened the antibacterial properties of heavy metal ions (Cd(II), Hg(II), Bi(III)), allowing the bacteria to survive higher concentrations thereof. Mixing the ligand and the metal ion salts without forming the complex beforehand enhanced the antibacterial properties of the cations. Being non-cytotoxic itself, the ligand therefore balances the biological consequences of heavy metal ions between toxicity and therapeutic weapons, depending on its use as a coordinating ligand or simple adjuvant.

Toxic heavy metal ions contamination in water and their sustainable reduction by eco-friendly methods: isotherms, thermodynamics and kinetics study

Heavy metal ions can be introduced into the water through several point and non-point sources including leather industry, coal mining, agriculture activity and domestic waste. Regrettably, these toxic heavy metals may pose a threat to both humans and animals, particularly when they infiltrate water and soil. Heavy metal poisoning can lead to many health complications, such as liver and renal dysfunction, dermatological difficulties, and potentially even malignancies. To mitigate the risk of heavy metal ion exposure to humans and animals, it is imperative to extract them from places that have been polluted. Several conventional methods such as ion exchange, reverse osmosis, ultrafiltration, membrane filtration and chemical precipitation have been used for the removal of heavy metal ions. However, these methods have high operation costs and generate secondary pollutants during water treatment. Biosorption is an alternative approach to eliminating heavy metals from water that involves employing eco-friendly and cost-effective biomass. This review is focused on the heavy metal ions contamination in the water, biosorption methods for heavy metal removal and mathematical modeling to explain the behaviour of heavy metal adsorption. This review can be helpful to the researchers to design wastewater treatment plants for sustainable wastewater treatment.

Solar interfacial evaporation for efficient treatment of sewage containing volatile organic compounds and toxic heavy metal ions: A sequential process of adsorption, coagulation, and evaporation

Solar interfacial evaporation (SIE) is an eco-friendly and sustainable technology for addressing water pollution and freshwater scarcity. However, treating wastewater containing volatile organic compounds and heavy metal ions with a single SIE method is inefficient. The combination of adsorption, coagulation, and evaporation process provides an alternative solution for treating this type of wastewater. In this study, activated carbon powder (C) is introduced as an adsorbent and an integral part of photothermal conversion material, which is coagulated with polyvinyl alcohol (PVA) and polyethylene glycol (PEG) through a mold press process to fabricate PVA/C/PEG composite hydrogels. The volatile organic compounds and heavy metal ions in the wastewater are adsorbed by the activated carbon powder and the wastewater is then further purified into freshwater through SIE. This stepwise “adsorption first, then coagulation and evaporation” method can not only rapidly remove pollutants from the raw water, but also provides a much higher removal efficiency than the adsorption-evaporation synergetic process. This work demonstrates a successful attempt to utilize the SIE method for treating wastewater containing volatile organic compounds and heavy metal ions.

Porous Silicon Nanoparticles Conjugated Magnetite‐Chitosan Graphene Oxide Nanoparticles for Effective Removal of Complex Pollutants

AbstractThe effective removal of complex pollutants is extremely challenging for environmental and material science, especially pollutants including detergents and pesticides do not decompose or degrade in the aquatic environment which cannot be easily removed. Here, a novel biocompatible superparamagnetic nanocomposite integrating the advantages of porous silicon nanoparticles is developed, the chelation ability of chitosan, and graphene‐oxide‐iron that can simultaneously adsorb complex hydrophobic and hydrophilic pollutants on their internal and external surfaces which have significantly improved pollutant removal efficiency over the current existing methods. A porous silicon nanoparticle (PSi) conjugated magnetite‐chitosan‐reduced graphene oxide (MCRGO) nanoparticles (PSi‐MCRGO) are synthesized for complete removal of detergent, pesticide, and toxic heavy metals cadmium and lead ions from water at a favorable room temperature. The adsorption behavior of the nanocomposites fits well with the Freundlich isotherm and pseudo‐second‐order kinetics model by adsorption mechanism. Moreover, the fresh and recycled nanocomposites are easily separated by an external magnetic field for reusability due to super magnetite response and show high binding capacity for toxic heavy metal ions. Furthermore, the nanocomposites are biocompatible and reusable, and for the fourth time, recycled nanocomposites can completely remove toxic heavy metals. Overall, the novel nanocomposites completely remove complex pollutants which hold great potential for real water treatment.

High‐Energy Ball Milling Synthesize All‐Inorganic Lead‐Free Green Emitting Cs3MnBr5 Crystals

AbstractLight Emitting Diodes (LEDs) are the key to new generation displays. New semiconductor electron–hole recombination layer is the key to high‐performance LEDs. Although all‐inorganic quantum dot (QD) materials have the advantages of wide color gamut and narrow emission peaks, they face issues of toxicity of heavy metal ions and stability of QDs, the synthesis method is highly polluting and difficult to achieve industrial production. Thereby, lead‐free all‐inorganic phosphor with narrow FWHM needs to be explored. A new synthesis method is required to be investigated. All‐inorganic Mn2+ bromide (Cs3MnBr5) is easy to synthesize and has low toxicity and superior luminescent properties. However, most synthesis methods rely on liquid‐phase reaction systems and cannot achieve highly efficient synthesis. High‐energy ball milling is an efficient method and has enormous potential for industrial production. In this paper, this method is used to synthesize Cs3MnBr5, and then Cs/Mn ratio, ball milling time, and ligand usage are studied. Furthermore, a new phase transformation of all‐inorganic Mn2+ bromide is discovered, and the mechanism of high‐energy ball milling is interpreted combining with phase transformation process. This article brings a new method to synthesis of all‐inorganic Mn2+ bromide, explains the mechanism of ball milling, and expands the phase transformation of all‐inorganic Mn2+ bromide.

Computational investigation of impact of Pb(II) and Ni(II) ions on hUNG enzyme: insights from molecular dynamics simulations

Human uracil DNA glycosylase (hUNG), a crucial player in the initiation of the base excision repair pathway, is susceptible to alterations in function and conformation induced by the accumulation of toxic metals. Despite the recognized impact of toxic metals on DNA repair enzymes, there exists a notable deficiency in theoretical investigations addressing this phenomenon. This study investigates the impact of toxic heavy metal ions, Pb(II) and Ni(II), on the stability of hUNG through molecular dynamics (MD) simulations. The initial analysis involved the identification of key cavities in the hUNG enzyme. Notably, the active site cavity emerged as a promising site for ligand binding. Subsequently, AutoDockTools software was employed to dock Pb(II) and Ni(II) onto the identified cavities, followed by extensive MD simulations. The MD analysis, encompassing parameters such as root mean square deviation, radius of gyration, solvent accessible surface area, hydrogen bond variations, Ramachandran plot, principal component analysis, and root mean square fluctuations, collectively revealed distinct alterations in the behavior of the enzyme upon complexation with Pb(II) and Ni(II). Interestingly, the enzyme exhibited enhanced structural stability, reduced flexibility, and modified hydrogen bonding patterns in the presence of these toxic metal ions. The observed limitation in structural flexibility implies a more rigid and stable conformation when the enzyme complex with Pb(II) and Ni(II) compared to its free form. This structural alteration may lead to a potential reduction in enzymatic activity, suggesting that toxic metal ions influence the functional dynamics of hUNG. These computational findings offer valuable insights into the molecular interactions between metal ions and enzymes. Communicated by Ramaswamy H. Sarma

Luminescent MOFs Based on Thiazolo[5,4-d]thiazole as a Chemosensor for the Detection of Environmental Contaminants

Luminescent metal-organic frameworks (LMOFs) are considered special candidates for the sensation and detection of particular analytes. Thiazolo[5,4-d]thiazoles (TTZs) are an ideal type of heterocycles for fluorophores with π-bridge moieties demonstrating structure-function characteristics. LMOFs with excellent sensing properties can be constructed by incorporating heterocyclic aromatic thiazolo[5,4-d]thiazole into the framework. This study has elaborated on LMOFs containing thiazolo[5,4-d]thiazole unit for the detection of environmental contaminants, such as toxic anions, aromatic compounds, and heavy metal ions.

Adsorptive removal of heavy metal ions from model aqueous media using titanium metal-organic framework and its polyvinyl chloride functionalized composite

The present study was conducted on Ti-MOF and its PVC functionalized composite with the objective of toxic heavy metal ions removal from aqueous media. For achieving this purpose, the solvothermal method was used to synthesis Ti-MOF which was then functionalized with PVC for composite synthesis. The synthesized adsorbent materials were then analyzed via different techniques that include the FTIR, XRD, SEM and EDX analysis along with TGA and point of zero charge (PZC). Batch experiments were conducted for nickel (Ni) and copper (Cu) metal ions sorption from water, using the synthesized adsorbents, under different experimental conditions like initial metal ions concentration, pH, adsorbent’s dosage, time of contact and temperature. The sorption of heavy metal ions by the adsorbents was increased with increasing the media dosage and concentration. Whereas, increasing the pH of the system, from pH-2 to pH-10, also enhanced the sorption phenomenon, because of the pronounced forces of attraction between the positively charged adsorbate ions and the adsorbent’s negatively charged surface, accompanied by precipitation at a much higher pH. It was observed that the adsorption on the functionalized adsorbent surface was greater than the parent MOF material because of the availability of a greater number of adsorption sites, increasing the adsorption capacity of Ni ions from 6.436 to 29.2 mg/g and that of Cu ions from 21.414 to 41.616 mg/g. In addition, the composite material was found to have greater affinity towards Cu metal ions as compared to Ni metal ions, which is attributed to the smaller size of Cu metal ions as compared to Ni ions. To determine the adsorption mechanism, various adsorption isotherms were examined. The results concluded that the Langmuir adsorption isotherm was the suitable model to explain the adsorption mechanism.Moreover, thermodynamic parameters like Gibbs free energy (, change in enthalpy, along with the change in entropy, were determined. The sorption process was found to be more spontaneous at lower temperatures, with the exothermic nature of adsorption, in the case of Ni metal ions and the endothermic nature in the case of Cu metal ions.Also, the negative value of ΔS in case of Ni ions adsorption accounts for the decreased disorderliness of the system which is also the opposite tothat of Cu ions adsorption onto the surface of Ti-PVC composite.The PVC functionalized Ti-MOF was thus found to be an effective, durable, and environmentally friendly adsorbent, for the sorption of heavy metal ions from wastewater.

Rational construction of MoSx via defect engineering for efficient removal of mercury ions from aqueous solution

Mercury ions (Hg2+) are one of the most physiologically toxic heavy metal ions in water. Developing adsorbents for separating and removing mercury ions from aquatic systems has important environmental and social significance. Owing to the hard-soft-acid-base interaction between mercury and sulfur (S) atoms, two-dimensional layered MoS2 holds great promise in capture physiologically toxic Hg2+ from water, but most S atoms are located inside the bulk MoS2, hindering the effective contact with mercury. Defects engineering is considered as an effective way to adjust the structure and achieve superior performance of MoS2. However, reasonable and fine defect modulation to enhance the mercury adsorption performance remains a challenging task. Herein, we reported that molybdenum sulfide with Mo-vacancy structure (MV-MoSx) was fabricated via hydrothermal method and employed to uptake Hg2+. The results showed that this defect type significantly increased the concentration of Mo stripping defects, exposed more active S atoms, and provided MoSx with excellent adsorption performance in adsorption capacity, adsorption kinetics, distribution coefficient, selectivity and so on. In particular, MV-MoSx demonstrates a substantial actual adsorption capacity for mercury, reaching as high as 3723.3 mg/g, which is in close proximity to its theoretical adsorption capacity of 3945.95 mg/g. More importantly, a functionalized composite aerogel system based on MV-MoSx was constructed, which successfully reduced the concentration of Hg2+ solution below the concentration permitted by drinking water standards. Our study not only provide a theoretical basis for the design of novel defect engineering, but also expand the application of transition metal sulfides in the enrichment and separation of heavy metal ions.

A Comprehensive Assessment of the Quality of Supplied Drinking Water in Galyang Municipality of Syangja, Nepal

A thorough assessment on the municipally supplied water samples from Malunga and Galyang cities; two different places in the Syangja district focused on analyzing various water quality parameters. These parameters included pH value, alkalinity, electrical conductivity, turbidity/suspended solids, chloride contents, and the presence of acid and basic radicals (heavy metal ions).
 The results obtained from standard laboratory probes carried out on-site and at the chemistry laboratory of Amrit Campus, indicated that the pH value, alkalinity, electrical conductivity, chloride contents, and the presence of acid radicals (nitrate, sulfate, and chloride) and basic radicals (toxic heavy metal ions) in the water samples were all within the safe limits for potable water as suggested by both the National Drinking Water Quality Standards (NDWQS) of Nepal and the World Health Organization (WHO).
 However, it was disclosed that the total suspended solids in the water samples existed in higher concentrations, leading to coagulation and the formation of thin, flat, whitish lumps during long-term storage of the samples.
 Overall, while the study determined that the water samples concurred the safe limits for most parameters set by NDWQS and WHO, the higher concentration of total suspended solids during prolonged storage suggests a potential attention to be paid for the improvement of the quality.

Molecular Probe Embedded Porous Polymer Scaffold as Solid‐State Visual Sensor for Selective and Sequential Sensing of Ultra‐Trace Toxic Heavy Metal Ions in Environmental/Commercial Samples

AbstractThe article reports on the tailor‐made solid‐state optical sensor through controlled imbuement of an amphiphilic probe onto a dual interwoven macro‐/meso‐porous polymer monolithic scaffold for the selective ocular sensing of ultra‐trace toxic heavy metal ions. The structural/surface morphology of the poly(LMC‐co‐TMP) monolith is customized through the stochiometric inclusion of lauryl methacrylate (LMC), trimethyl propanetrimethacrylate (TMP) and porogenic solvents. The riveting sensing performance of the poly(LMC‐co‐TMP) scaffolds for the target ions arises from the built‐in twofold intermingled porous architects that render voluminous surface area and porosity for the embedding of 2‐((1H‐benzoimidazol‐2‐yl)‐4‐butan‐2‐yl)phenol (HBBP), a chromoionophoric probe. The sensor's unique structural and surface properties endure stable ion‐complexation through color transitions from yellow (blank) to a leafy green, peanut brown, and dark blue for Pb2+, Hg2+, and Cd2+, respectively. The sensor imposes high binding affinity for the target ions, with a linear response range of 0–200 ppb for Pb2+/Hg2+ and 0–300 ppb for Cd2+. The detection limit values are 0.46, 0.52, and 0.41 ppb for Pb2+, Hg2+, and Cd2+, respectively. The sensor's hassle‐free on‐field testing in environmental and synthetic samples reveals excellent data reproducibility (Relative Standard Deviation (RSD) ≤1.97%), with pH‐assisted reliable color transitions for eight regenerative trials, with a response time of 45 s.

Fabrication of PVDF@MOF-303 membrane with Mortise-Tenon structure by the polyphenol analogue-assisted growth strategy for oil-water separation and heavy metal adsorption

This study applied a novel strategy to modify an inert fluorine-containing surface by combining alkaline lignin (AL) and silk fibroin (SF), introducing many active sites. The intercalation sites of SF during the formation of the AL coating allow the shape of the Mortise-Tenon metal-organic framework (MOF). MOF-303 with a Mortise-Tenon structure was grown on the surface of the membrane. The PVDF@MOF-303 membrane possesses superhydrophilic/underwater superoleophobic properties. The modified membrane showed perfect resistance to oil adhesion. Stable oil-in-water emulsions and toxic heavy metal ions can be separated by the PVDF@MOF-303 membrane with a Mortise-Tenon structure. This membrane has achieved outstanding oil-in-water emulsion separation efficiency (over 99.2 %) and flux (over 4200.0 L m−2 h−1 bar−1). After ten repeated experiments, a separation efficiency of 93.0 % was obtained. This membrane was used for heavy metal adsorption with high capacity (over 3374.4 mg m−2) and efficiency (over 99.6 %). Even more importantly, harmful heavy metal ions soluble in water can be effectively removed during emulsion separation. It can modify other substrates due to the easy preparation method and efficient performance described in this report.

Application of Graphene Technology in the Removal of Heavy Metal Ions in Wastewater

Nowadays, heavy metal pollution has become a serious problem. Toxic heavy metal ions can result in extreme damage to the environment and human society. Under that situation, methods that can remove the heavy metal ions in water have been required. Graphene technology can be widely applied to the removal of heavy metal ions. This article will explain the preparation of graphene oxide and reduced graphene oxide and the efficiency and influence factors of the method applied in water treatment. The method can remove many kinds of mainly occurring toxic heavy metal ions with very high efficiency. Also, large-scale production of graphene oxide can be achieved. The removal of heavy metal ions in water by graphene technology can be a practical method in the water treatment field.

A review of the application of nanoparticles as collectors in ion flotation

Ion flotation is one of the most promising and unique methods for reducing or removing toxic heavy metal ions, organic pollutants, or inorganic anions and cations from mining and metallurgical wastewaters. It is a cost-effective and convenient method. In ion flotation, surface-active ions are removed from aqueous solutions by adding surfactants. Therefore, the main purpose of this review article was to summarize the application of various surfactants (nanoparticle surfactants, chemical synthetic surfactants and biosurfactants) used in ion flotation. Then, the advantages, disadvantages, and prospects of surfactants were comprehensively discussed. Recent progress regarding nanoparticle surfactants in ion flotation and the mechanism of colligends binding with nanoparticles were evaluated.

Efficient remediation of heavy metal-contaminated water using a magnetically collectible nanoscale Cu/Fe/rGO primary battery

The removal of highly toxic heavy metal ions is essentially the migration of heavy metal ions from water to materials through adsorption, complexation, exchange, and other forms. However, heavy metals still exist as highly toxic ions on the surface of materials, easily desorbed, and cause secondary pollution. In this study, a novel primary battery of graphene-supported zero-valent copper/iron bimetallic composites (Cu/Fe/rGO) was first prepared with copper as the positive electrode, iron as the negative electrode, and graphene as the "wire". The network-like nanoscale primary battery was fabricated for the reduction and removal of typical highly toxic heavy metal ions (Pb2+) from the water environment. The removal rate of Pb2+ within 20 min was 95.28%. The Pb-immobilized Cu/Fe/rGO primary battery after treatment can be easily separated via a weak magnetic field and maintained an excellent removal rate of Pb2+ during 6 cycles of use. The great potential of Cu/Fe/rGO primary battery in Pb2+ reduction removal was due to its high reduction ability, large surface area, and magnetic separability. This study provides an important foundation for the rapid and stable removal of heavy metals from water, which may have a tremendous application prospect in environmental fields.

Design of a porous lignocellulose-based hydrogel-Pd nanoparticles reactor system and its in-situ simultaneous adsorption-catalysis process concept for pollutant remedy

The separation and reusability of nano-catalysts are paramount for their high-efficiency and low-cost use. Herein, lignocellulose hydrogels (LCG), were fabricated and served as the host matrix for in-situ generated palladium nanoparticles (Pd NPs), creating hydrogel-based Pd NPs reactor systems. The lignocellulose hydrogel-based Pd NPs (LCG/Pd NPs) reactor system possesses the following unique features: (1) lignin present in LCG acts as a “green” reducing agent so that Pd NPs are formed in situ; (2) the in-situ generated Pd NPs are well dispersed in the LCG structure via complexation; (3) the simultaneous adsorption-catalysis process concept is very effective for pollutant remedy: the adsorption of pollutants on the porous LCG effectively increases the pollutant concentration on the reaction sites, where the Pd NPs are co-located, enhancing the catalytic reactions; as a result, a much higher catalytic reaction rate is observed; (4) the LCG/Pd NPs reactor systems are readily reused/recycled after each use. As proof of this concept, the catalytic performance of the LCG/Pd NPs reactor system was demonstrated by the catalytic reduction of toxic heavy metal ions (Cr6+) and organic dye (methyl orange). Results showed that the novel LCG/Pd NPs reactor system exhibited much increased catalytic reduction rates: the pseudo-first-order rate constant (k) is 118 times higher (from 0.018 to 2.129 min−1 at 25 °C) for MO, and 38 times higher (from 0.008 to 0.304 min−1 at 25 °C) for Cr6+, in comparison with the control, under otherwise the same conditions.

Preparation and characterization of ball milled hexagonal‑boron nitride (BMBN) and fluorescein (FL) decorated reduced graphene oxide (RGO) nanocomposite towards toxic heavy metal ion detection

In the present work, a novel hybrid fluorescent nanocomposite (RBF) based on ball milled hexagonal-Boron Nitride (BMBN) and Fluorescein (FL) decorated reduced Graphene Oxide (RGO) was synthesized for the effective detection and removal of hazardous heavy metal ions present in effluents. Where two different textile effluents namely, reaction outlet and factory outlet collected at the river Noyyel, Tamilnadu were considered. The prepared RBF was subjected to XRD, FTIR, SEM, EDX, TEM, PSA, BET, UV–vis, PL and XPS studies which strongly confirm the decoration of FL and BMBN at the surface of RGO sheets. The selectivity of RBF was examined by considering various toxic heavy metal ions. Where the RBF exhibits remarkable sensing towards Zn2+ (10.7 nM) via enhanced fluorescence and for Fe3+ (15.6 nM), Sn4+ (60.7 nM) and Hg2+ (465.4 nM) ions by “Turn-off” fluorescence only at neutral pH. In addition, the RBF was highly efficient to remove Hg (81.3 %) than Zn (63.7 %), Fe (38.2 %) and Sn (62.9 %) in real-time samples. Moreover, the prepared RBF could also serve as water sensor for the water contaminated organic solvents of Acetonitrile (ACN) and Tetrahydrofuran (THF). Hence the prepared RBF might be a potential choice for the effective detection and removal of heavy metal ions during wastewater treatment.

Enhancing lettuce yield via Cu/Fe-layered double hydroxide nanoparticles spraying

Layered double hydroxides (LDHs) have been widely used in the field of plant engineering, such as DNA/RNA transformation and enhancing plant disease resistance. However, few studies have examined the direct effects of LDHs on plants and their potential utility as nanofertilizers. In this study, the retention capacity of Cu/Fe-layered double hydroxide nanoparticles (CuFe-LDHs) was assessed by comparative experiments on vegetables. The results showed that the retention of CuFe-LDHs in leafy vegetables was high, such as lettuce. Phenotypic analysis revealed that the fresh and dry weights of lettuce leaves were both increased by spraying 10–100 μg/mL CuFe-LDHs. Using the optimal concentration of 10 μg/mL, we conducted further experiments to elucidate the mechanism of CuFe-LDHs promoting lettuce growth. It was found that the application of CuFe-LDHs had a significant effect on growth and induced physiological, transcriptomic, and metabolomic changes, including an increase in the chlorophyll b content, net photosynthetic rate, and intercellular carbon dioxide concentration, as well as modifications in gene expression patterns and metabolite profiles. This work provides compelling evidence that CuFe-LDHs can efficiently adsorb on the surface of lettuce leaves through hydrogen bonding, promote lettuce growth, mitigate the toxicity of heavy metal ions compared to their raw materials at the same concentration and offer a molecular-scale insight into the response of leafy vegetables to CuFe-LDHs.Graphical

Heterogeneous single-atom doped 2D-layered graphitic carbon nitride electrocatalyst for oxygen evolution reaction and removal of toxic heavy metal ion Cr from Wastewater

The 2D-layered graphitic carbon nitride (gCN) has been a well-known electro-photocatalyst to have wide applications in energy storage, energy evolution, and environmental remediation. The physicochemical properties of the bulk, O-doped (O-gCN), and hetero atom are compared, which is further utilized as an electrocatalyst for the oxygen evolution reactions (OER) process. The prepared nanosheets exhibited a layered structure with a uniform porous nature. Moreover, the forbidden energy bandgap (Eg) of 1.7 eV is observed, which is lower than bulk and O-doped gCN. The heteroatom BO-gCN nanosheets have higher OER activity compared to other samples and benchmark catalysts. The BO-gCN nanosheets exhibit a lower overpotential and Tafel potential of 240 mV and 207 mV/dec, respectively. Effects of various operating parameters such as photocatalyst dosage and solution pH are investigated. The photocatalytic removal results exhibited BO-gCN can be a robust and effective catalyst for the removal of Cr ions in environmental remediation.

Ti3C2Tx MXene-derived hydroxyl-rich titanate based hybrid membrane with cellulose as structural regulator for highly-efficient disposition of heavy metal ions

Exploring an efficient and stable adsorbent material for purification of toxic heavy metal ions wastewater is of great significance. However, as a typical heavy metal ions adsorbent, titanate can still improve in material synthesis, adsorption efficiency and the recyclability. Herein, a novel titanate-based adsorbent which composing of Ti3C2Tx MXene-derived hydroxy-rich titanate and cellulose was fabricated for efficient removal of toxic heavy metal ions. Owing to the similar stratified structure, the conversion from Ti3C2Tx MXene to titanate is energy-saving and easy to achieve. In addition, the inherited hydroxy-rich property is beneficial to improve the adsorption efficiency of the derived titanate. Furthermore, the introduction of cellulose as a structural regulator to fabricate the titanate/cellulose membrane could greatly alleviate the problem of difficult recycling of powder adsorbent. Thus, the constructed Ti3C2Tx-derived hydroxy-rich titanate/cellulose membrane adsorbent (M-NTO/CM) exhibits high Cu2+ adsorption capacity of 2.63 mmol g−1 and can reach the adsorption equilibrium in only 5 min. Better yet, there has also been a significant improvement in acid resistance and recyclability of the M-NTO/CM relative to traditional titanate. In short, M-NTO/CM derived from Ti3C2Tx MXene can be used as an advanced membrane for convenient and efficient purification of heavy metal ions from the wastewater.