Noxious Pollutants Research Articles

Bi-functional NiFe2O4/SrTiO3 S-scheme heterojunction for eminent performance photocatalytic treatment of sewage effluent and electrochemical hydrazine determination

Devising of materials that afforded dual applicability in decontamination and pollutant detection were still a towering challenge owing to the increasing flux of discharge toxic contaminants over the years. Herein, the NiFe2O4 nanoparticles-loaded on cube-like SrTiO3 (NiFe2O4/SrTiO3) composite was fabricated by a two-step hydrothermal approach providing remarkable photocatalytic treatment and electrochemical sensing of noxious pollutants in wastewater. The material traits of the fabricated composite were scrutinized by myriad characterization approaches. The NiFe2O4/SrTiO3 hybrid material demonstrated high surface area of 19.81 m2/g, adequate band gap energy of 2.75 eV, and prominent photoluminescence characteristics. In the presence of visible light, the NiFe2O4/SrTiO3 exhibited profound photocatalysis capability to eliminate sewage effluent-bearing chlortetracycline hydrochloride (CTCH) with 88.6% COD removal in 120 min, outperforming other pure materials. Meanwhile, the toxicity examination of effluent, the possible degradation pathway of CTCH and the proposed photocatalysis mechanism were also divulged. More importantly, the glassy carbon electrode was modified with synergized NiFe2O4/SrTiO3 (NiFe2O4/SrTiO3−GCE) was adopted for the precise quantification of Hydrazine (Hz). The NiFe2O4/SrTiO3−GCE obeyed first-order response for the Hz detection within the range of 1–10 mM: cyclic voltametric: limit of detection (LOD) of 0.119 μM with sensitivity of 18.9 μA μM−1 cm−2, and linear sweep voltametric: LOD of 0.222 μM with a sensitivity of 12.05 μA μM−1 cm−2. The stability and interference of modified electrode were also inspected. This work furnished valuable insights to yield a composite with the prominent S-scheme heterojunction system for quenching of charge carrier recombination and consequently contributing to the future realization into the domains of environmental clean-up and toxic chemical detection.

Remediation of lead toxicity with waste-bio materials from aqueous solutions in fixed-bed column using response surface methodology

Heavy metal ions pose significant risks to human health, pelagic, and several other life forms due to perniciousness, tendency to accumulate, and resistance to biodegradation. Waste bio-materials extend a budding alternative as low-cost adsorbent to address the removal of noxious pollutants from wastewater on account of being cost-effective and exhibiting exceptional adsorption capacities. The current exploration was accomplished to gauge the performance of raw and modified human hair concerning lead scavenging in a down-flow fixed bed column. The appraisal of column performance under varying operational parameters encompassing bed height (15–45 cm), influent metal ion concentration (60–140 mg L−1), and a solution flow rate (20–40 mL min−1) was performed by breakthrough curve analysis. The consequences acquired were evaluated using the Yoon Nelson, Thomas, Adam-Bohart, and Bed Depth Service Time (BDST) model. Among these employed models, Bed Depth Service Time (BDST) and Thomas models exhibited the highest R-squared value compared to the Yoon Nelson and Adam-Bohart's model for most cases. In addition, the optimization of lead adsorption was followed using the Box-Behnken design of response surface methodology (RSM). The optimal conditions (desirability-1.00) for achieving a goal of maximum percent removal of lead ions were marked to be a bed height of 42.79 cm, solution flow rate of 20.92 mL min−1, and an initial metal concentration of 139.51 mg L−1. Under these optimized conditions, the percent amputation of lead in a fixed bed was observed to be 82.31 %, while the results of the experiment performed approximately under these optimized conditions revealed a percent removal of 85.05 %, reflecting a reasonable conformity with values acquired through Box-Behnken design.

Optimizing Copper Adsorption from Aqueous Solutions with Modified Rice Straw Using Response Surface Methodology

Heavy metal contamination poses an impulsive threat to human and aquatic life and ecosystem health. To ensure safe and sustainable water accessibility, biosorption with low-cost adsorbents is acknowledged as a promising approach for the remediation of noxious pollutants. The current study was oriented to appraise the performance of modified rice straw for copper adsorption in hand with the optimization of its operational parameters. RSM-based Box-Behnken design was employed to optimize the operational variables encircling temperature, pH, and adsorbent dose. The results elucidated that the generated model exhibited an R-squared of 0.98, reflecting its validity in describing the experimental data well. The optimized conditions for attaining maximum copper adsorption were marked to be a temperature of 37.71 oC, a solution pH of 5.7, and an adsorbent dose of 11.26 g L-1. Under these optimized conditions, the adsorption efficiency was marked to be 86.65 %. The experimental adsorption efficiency under these conditions was noted to be approximately 86.43 %, reflecting the suitability of the RSM-based Box-Behnken design. Conclusively, it can be inferred that acid modified rice straw offers a promising low cost adsorbent for remediation of heavy metals in accordance with the principles of green chemistry.

Review on recent advancements of 2D MXene-based nanostructures on different possible approaches for wastewater treatment

In this review, a brief perspective of MXene (since 2011) with recent research for new and advanced applications for wastewater treatments through various approaches have been discussed. Current information’s about MXenes are summarized to fully understand their nature, promising properties and reduce the challenges that have opened the new era of their uses. Primarily, the existing modest problem is the availability of potable water to sustain healthy human-chain and entire ecosystem, as contaminated water has harsh consequences and poses serious threats to human-health worldwide. In the current stage, supply of potable water for society with cheap and low-cost technology has become the key requirement for the growing economy. Efficient techniques to remove several contaminants (including dyes, heavy metal ions, pharmaceutical or organic products) from wastewater have been transformed gradually to mitigate this scarcity. In this direction, MXene based nanostructures have become a promising material for the wastewater treatment. These structures have unique hydrophilicity, high surface area, a good photocatalytic activity, and wonderful adsorption capacity for contaminates. Numerous advanceshavebeen observed in the optimized rational designs of MXene-derived nanocomposites and their applications in wastewater purification. Hence, timely updates are necessary to emphasize on toxic removals and characterizations including merits and demerits of these MXene-based nanostructures. Thus, this study summarizes the guidelines for the synthesis and applications of MXene-based nanocomposites in wastewater purification, which may stimulate the scientific community to develop a variety of MXene-derived nanostructures with well-defined structures, constitution, and enhanced physicochemical properties for effectively removal of noxious pollutants from wastewater using cost-effective and feasible techniques.

Highly efficient photocatalytic removal of antineoplastic drug and selective fluorescence detection of organophosphate pesticide employing NiFe2O4 modified 2D g-C3N4 heterostructures

With the goal to detect, quantify and remove virulent toxins for water decontamination, a dual functional platform based on nickel ferrite (NF) modified magnetically retrievable 2D metal free g-Carbon Nitride (CN), with varied ratios of NF, was fabricated via simple sonication-calcination route. The % degradation of antineoplastic drug, doxorubicin (DXR) were obtained to be 69.8 %, 49.1 %, 71.1 %, 85.4 %, 94.2 %, 88.5 % and 81.7 % for CN, NF, 2-CNNF, 4-CNNF, 6-CNNF, 8-CNNF and 10-CNNF, respectively with corresponding rate constant values of 0.069, 0.047, 0.075, 0.100, 0.148, 0.113 and 0.078 min−1. CNNF heterostructure displayed outstanding photocatalytic performance with 6-CNNF heterostructure displaying highest rate kinetics with rate constant value 2.2 and 3.2 times greater than pure CN and NF, respectively. The charge transfer occurring in CNNF heterostructure followed direct Z-scheme mechanistic pathway, which proffers two advantages of high photoinduced charge carriers separation and optimized redox capacity of binary system. UV–vis DRS, XPS and PL results supported the proposed mechanism. Radical scavenging experiments further validated the role of •O2−, h+ and HO• radicals in degrading target pollutant. Moreover, the fabricated material was efficiently employed as selective and sensitive sensor for fluorescence detection of pesticide, chlorpyrifos (CPF) and DXR with respective LOD values of 4.1 µM in the range of 5 µM to 100 µM and 1.6 µM in the range of 0.1 µM to 40 µM. Real world applicability was established by monitoring CPF and DXR in real water samples. This study presents the designing of multi-functional platform, exhibiting excellent optical as well as physical characteristics, for monitoring and obliteration of noxious pollutants in aqueous environment.

Catalytic evaluation of solid state hand-crafted bimetallic nanocore-shell composite via green reducing agent

The material fabrication via greener way as well as the magnetic nature for easy recoverability of the catalyst offers a way to put forth on material as Azadirachta indica (AI) decorated Fe3O4 @Ag-Cu nanocomposite. The nanocomposite (NC) was prepared by an eco-friendly one-step hand-made grinding method. Herein, the AI powder acts as a greener reducing and stabilizing agent for preparing nanocomposite (NC). The successfully synthesized bimetallic catalyst was examined with the help of HR-TEM, FE-SEM, XPS, VSM, XRD, FT-IR, and UV–vis studies. On average, the size of NC range was around 21 ± 3 nm, and the NC was spherical in shape while the metal nanoparticles (MNPs) were uniformly distributed over the surface of the AI extract. The green catalyst prepared by varying ratios of the metals was examined for the treatment of pollutant water-containing dyes and pharmaceutical waste. The core advantage of the green synthesized catalyst was tested for the photo-reduction of well-known pharmaceutical waste, such as paracetamol and ciprofloxacin in an efficient manner, and their rate constants were 3.82 × 10−2 min−1 and 1.27 × 10−2 min−1 respectively. Furthermore, the NC acquires the capability to degrade carcinogenic pollutants like Xylene Cyanol FF (XC) and Malachite Green (MG) at 86% and 82%, respectively. Despite this, it shows good antibacterial activity towards gram-positive (B. subtilis and S. aureus) as well for gram-negative bacteria (E. coli, P. aeruginosa). The catalyst was also employed for the reduction of 4-Nitrophenol (4-NP). A comparative strategy for the reduction of the pollutants with the help of sodium borohydride vs the photo-reduction were analyzed in these strategical studies. was Thus, the bimetallic catalyst flagged a better way to reduce pharma compounds and several noxious pollutants due to its low cost, highly efficient, and reusability holding good for many cycles.

Aucubin mitigates nonylphenol-induced renal damage by attenuating apoptosis, oxidative stress and histopathological profile

Nonylphenol (NP) is potent noxious pollutant which is documented to induce nephrotoxicity via escalating the levels of oxidative stress in renal tissues. Aucubin (AUC) is a novel phytochemical having tremendous pharmacological abilities. This research aimed to estimate the efficacy of AUC against NP intoxicated renal impairment in male albino rats. 48 albino rats were randomly assigned into four different groups viz. control group, NP administered group (50 mg/kg), NP + AUC administrated (50 mg/kg + 40 mg/kg) group and AUC treated (40 mg/kg) group. Our results showed that NP intoxication raised urinary proteins, creatinine, urea, urobilinogen, NGAL and KIM-1 levels. Besides, NP exposure lowered the levels of creatinine clearance and albumin. Furthermore, NP treatment lowered level of total protein, activities of catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione S-transferase (GST), glutathione reductase (GSR) & glutathione (GSH) contents along with the level of total antioxidant status (TAS) however, raising the oxidative stress markers levels Thiobarbituric acid reactive substance (TBARS), reactive oxygen species (ROS), hydrogen peroxide (H2O2) & total oxidant status (TOS). Additionally, following the NP administration, the levels of Bax, caspase-9, & caspase-3 were augmented however the Bcl-2 level was decreased. Furthermore, rats exposed to NP showed various histopathological disruptions. Whereas treatment with AUC showed a palliative effect against NP-induced renal damage, restoring all alterations to normal levels. Taken together, AUC administration convalesced NP-induced kidney impairment.

A fluorescent biomass derived cellulose/PANI/NiFe2O4 composite for the mitigation of toxic pollutants and Cr(VI) sensing from aqueous environment

Targeting routine water pollution due to industries and biowaste management, present work focuses on synthesis of biomass derived photocatalysts for abatement and detection of noxious pollutants. Herein, a series of nickel ferrite/cellulose-polyaniline composites (NF/C-PA) were fabricated via hydrothermal route and were successfully characterized. The comparative analysis of all the synthesized composites was carried out for photo-Fenton degradation of different pollutants, namely, Remazol brilliant yellow (RBY), Safranin O (SO) dyes, Levofloxacin (LVX) and Ofloxacin (OFX) drugs, and para-nitrophenol (PNP). Amongst all composites, NF/C-PA 1.5 bestowed best photocatalytic results with a degradation value of 95.42 % (k1 = 0.0859 min−1), 93.42 % (k1 = 0.0859 min−1), 91.96 % (k1 = 0.0731 min−1), 87.44 % (k1 = 0.1213 min−1), and 90.73 % (k1 = 0.1195 min−1) within 30 min for RBY, SO, LVX, OFX and PNP, respectively. Furthermore, the synthesized NF/C-PA 1.5 composite was successfully employed as fluorescence probe for selective and sensitive detection of Cr(VI) in wastewater with the limit of detection value 4 µM in the linear range of 0 to 200 µM. The sensor demonstrated virtuous pertinency in real water samples. Thus, the synthesized biobased composites exhibited multifunctional platform for the removal and detection of pernicious contaminants from aqueous environment.

Unveiling the noxious effect of polystyrene microplastics in aquatic ecosystems and their toxicological behavior on fishes and microalgae.

Microplastic (MP) particles are considered noxious pollutants due to their presence in aquatic habitats at almost every level of the food chain. Thus, the entry of MP particles into marine waterbodies has triggered a common research interest. Until recently, the toxicity of polystyrene towards aquatic creatures in comparison to other polymers has not been widely investigated. This article provides an extensive overview of the occurrence of microplastic particles, the route of polystyrene (PS) in the aquatic ecosystem, the PS properties characterization, and its noxious effects on the aquatic biota, particularly fishes and microalgae. Alarming high levels of polystyrene were found in urban, coastal, and rural surface waters and sediments. The fast-screening technique began with a stereoscope to determine the polystyrene particles' shape, size, and color on the organism. SEM and complemented by micro FTIR or Raman spectroscopy were used to evaluate MP's polymer structures. The findings present evidence suggesting that polystyrene buildup in fish can have long-term and unknown consequences. Meanwhile, the presence of polystyrene on microalgae causes a decrease in chlorophyll concentration and photosynthetic activity, which may disrupt photosynthesis by interfering with the electron characters and leading to the production of reactive oxygen species (ROS).

Long-term atmospheric pollutant emissions from a combined cycle gas turbine: Trend monitoring and prediction applying machine learning

Carbon monoxide (CO) and oxides of nitrogen (NOx) are noxious pollutants associated with combined cycle gas turbine (CCGT) power plants that require careful monitoring and control. A publicly available dataset links five years of hourly CCGT emissions to nine recorded operational/environmental variables. This study applies twelve multi-linear regression (MLR) and machine learning (ML) models to rigorously predict CO and NOx for that dataset with a novel analytical sequence. Statistical distributions of the data reveal time shifts in the CO and NOx values that cannot be explained by the recorded variables. The relative variable weights applied to the variables by the certain MLR/ML models identifies that their relative importance in influencing CO and NOx predictions varies substantially. Multi-K-fold cross validation is applied to establish the prediction accuracy of each model and indicate the most suitable data-record splits for training and validation. Trained K-nearest neighbour (KNN) and extreme gradient boosting (XGB) ML models consistently provide the most reliable CO and NOx emission predictions with least errors when applied to unseen test data. Consideration of mean errors and predicted versus measured data trends make it possible to identify and partially correct MLR/ML predictions for systematic time shifts in the CO and NOx data. The best performing KNN models generate mean average errors of 0.8458 mg/m3 for CO (∼1.9 % of the CO data range) and 5.1234 mg/m3 for NOx (∼5.5 % of the NOx data range) for a two year period separate from the model’s training/validation period.

Biochar as Sustainable Alternative and Green Adsorbent for the Remediation of Noxious Pollutants: A Comprehensive Review

The current water crisis necessitates the development of new materials for wastewater treatment. A variety of nanomaterials are continuously being investigated for their potential as adsorbents for environmental remediation. Researchers intend to develop a low-cost, simple, and sustainable material that can cater to removal of pollutants. Biochar derived from biowaste is a potential candidate for the existing problem of water pollution. The review focuses on the various aspects of biochar, such as its sources, preparation methods, mechanism, applications for wastewater treatment, and its regeneration. Compared with other adsorbents, biochar is considered as an environmentally friendly, sustainable, and cost-effective substitute for waste management, climate protection, soil improvement, wastewater treatment, etc. The special properties of biochar such as porosity, surface area, surface charge, and functional groups can be easily modified by various chemical methods, resulting in improved adsorption properties. Therefore, in view of the increasing environmental pollution and the problems encountered by researchers in treating pollutants, biochar is of great importance. This review also highlights the challenges and prospective areas that can be explored and studied in more detail in the future.

Various surface-active agents used in flotation technology for the removal of noxious pollutants from wastewater: a critical review

Treating emerging pollutants from industrial effluent that cause inevitable damage to human wellness and the environment is paramount.

Biosorption of Methylene blue using clove leaves waste modified with sodium hydroxide

Water pollution with carbon-based dyes is a critical environmental problem owing to the severe life-threatening issues associated with their ingestion by humans and the associated release of dye molecules into the ecosystem. Before being released into the environment, a number of techniques and technologies have been researched to remove dye and other harmful compounds from textile and industrial effluents. Currently, scientists are looking at the efficacy of new, low-cost, and biodegradable biomaterials for removing noxious pollutants like methylene blue (MB) from water bodies and the ecosystem. In this study, clove leaves (CL) activated with sodium hydroxide (NaOH) were employed as a bio-sorbent for the confiscation of MB. The produced CL-NaOH bio-sorbent was typified by employing Scanning Electron Microscopy (SEM) and Fourier Transform Infrared Spectroscopy (FTIR) to ascertain the physiochemical properties of the CL-NaOH bio-sorbent. The response surface methodology (RSM) was employed to create a mathematical model and optimize the biosorption process of MB removal using activated CL-bio-sorbents using NaOH. Analysis of the variance (ANOVA) of the biosorption of MB showed the relative significance of the process parameters in MB confiscation. The biosorption process of MB to CL-NaOH bio-sorbent was perfectly defined utilizing the Freundlich (FRH), Langmuir (LNR) and pseudo-first-order (PFO) models. The established biosorption capacity was approximately 9.80 mg.g−1. Also, the calculated parameters of thermodynamics revealed that the biosorption of MB to the bio-sorbent was non-spontaneous and endothermic, with the process involving chemical sorption with high biosorption energy. Conclusively, this study reveals that the CL-NaOH bio-sorbent is a cost-efficient and recyclable bio-sorbent for the sequestration of MB from water-soluble solutions.

Comparative Performance and Emissions of CI Engine Fuelled with Diesel and Blends of Mosambi Peel Pyro Oil, Methanol and Nano Rh2O3 with Diesel

This research article presents a comparative experimental study on the performance, exhaust emission and combustion characteristics of a CI engine fuelled with neat diesel and with three kinds of blends viz. MD10 (neat diesel with 10% mosambi peel pyro oil), MDM10 (neat diesel with 10% mosambi peel pyro oil and 10% methanol), MD10+Rh2O3 (neat diesel with 10% mosambi peel pyro oil and nano rhodium oxide fuel additive). The experiments were conducted on a direct injection single-cylinder water-cooled four-stroke diesel engine operated at a constant engine speed of 1500 rpm and under varied brake power conditions. The results showed that MD10+Rh2O3 outperformed the rest in terms of all the performance, emission and combustion characteristics. MD10+Rh2O3 was found to have achieved, 5% higher brake thermal efficiency, 18.5% reduced SFC and 8% reduced exhaust gas temperatures respectively. This fuel has also achieved 10.5%, 5.5%, 9.45%, 11% marginal drop in noxious pollutants such as CO (Carbon Monoxide), unburnt HC (Hydrocarbons), NOx and smoke respectively. Cylinder peak pressures, heat release rate, ignition delay and combustion duration of MD10+ Rh2O3 are recorded to be considerably improved. Thus, using the nanoparticle added mosambi peels pyro oil (NMPPO) blended with diesel as an alternative fuel could impart an eco-friendly, efficient and improved engine operation.

Removal of tetracycline from wastewater using g-C3N4 based photocatalysts: A review

Tetracycline is currently one of the most consumed antibiotics for human therapy, veterinary purpose, and agricultural activities. Tetracycline worldwide consumption is expected to rise by about more than 30% by 2030. The persistence of tetracycline has necessitated implementing and adopting strategies to protect aquatic systems and the environment from noxious pollutants. Here, graphitic carbon nitride-based photocatalytic technology is considered because of higher visible light photocatalytic activity, low cost, and non-toxicity. Thus, this review highlights the recent progress in the photocatalytic degradation of tetracycline using g–C3N4–based photocatalysts. Additionally, properties, worldwide consumption, occurrence, and environmental impacts of tetracycline are comprehensively addressed. Studies proved the occurrence of tetracycline in all water matrices across the world with a maximum concentration of 54 μg/L. Among different g–C3N4–based materials, heterojunctions exhibited the maximum photocatalytic degradation of 100% with the reusability of 5 cycles. The photocatalytic membranes are found to be feasible due to easiness in recovery and better reusability. Limitations of g–C3N4–based wastewater treatment technology and efficient solutions are also emphasized in detail.

Nanotechnology- A ray of hope for heavy metals removal

Environmental effects of heavy metal pollution are considered as a widespread problem throughout the world, as it jeopardizes human health and also reduces the sustainability of a cleaner environment. Removal of such noxious pollutants from wastewater is pivotal because it provides a propitious solution for a cleaner environment and water scarcity. Adsorption treatment plays a significant role in water remediation due to its potent treatment and low cost of adsorbents. In the last two decades, researchers have been highly focused on the modification of adsorption treatment by functionalized and surface-modified nanomaterials which has spurred intense research. The characteristics of nano adsorbents attract global scientists as it is also economically viable. This review shines its light on the functionalized nanomaterials application for heavy metals removal from wastewater and also highlights the importance of regeneration of nanomaterials in the view of visualizing the economic aspects along with a cleaner environment. The review also focused on the proper disposal of nanomaterials with crucial issues that persist in the adsorption process and also emphasize future research modification at a large-scale application in industries.

Leveraging the potential of silver nanoparticles-based materials towards sustainable water treatment.

Increasing demand of pure and accessible water and improper disposal of waste into the existing water resources are the major challenges for sustainable development. Nanoscale technology is an effective approach that is increasingly being applied to water remediation. Compared to conventional water treatment processes, silver nanotechnology has been demonstrated to have advantages due to its anti-microbial and oligodynamic (biocidal) properties. This review is focused on environmentally friendly green syntheses of silver nanoparticles (AgNPs) and their applications for the disinfection and microbial control of wastewater. A bibliometric keyword analysis is conducted to unveil important keywords and topics in the utilisation of AgNPs for water treatment applications. The effectiveness of AgNPs, as both free nanoparticles (NPs) or as supported NPs (nanocomposites), to deal with noxious pollutants like complex dyes, heavy metals as well as emerging pollutants of concern is also discussed. This knowledge dataset will be helpful for researchers to identify and utilise the distinctive features of AgNPs and will hopefully stimulate the development of novel solutions to improve wastewater treatment. This review will also help researchers to prepare effective water management strategies using nano silver-based systems manufactured using green chemistry.

Nanoporous carbon materials as a sustainable alternative for the remediation of toxic impurities and environmental contaminants: A review.

Due to rapidly deteriorating water resources, the world is looking forward to a sustainable alternative for the remediation of noxious pollutants such as heavy metals and organic and gaseous contaminants. To address this global issue of environmental pollution, nanoporous carbon materials (NPCMs) can be used as a one-stop solution. They are widely applied as adsorbents for many toxic impurities and environmental contaminants. The present review provides a detailed overview of the role of different synthesis factors on the porous characteristics of carbon materials, activating agents, reagent-precursor ratio and their potential application in the remediation. Findings revealed that synthetic parameters result in the formation of microporous NPCMs (SBET: >4000 m3/g; VTotal (cm3/g) ≥ 2; VMicro (cm3/g) ≥ 1), micromesoporous (SBET: >2500 m3/g; VTotal (cm3/g) ≥ 1.5; VMicro (cm3/g) ≥ 0.7) and mesoporous (SBET: >2500 m3/g; VTotal (cm3/g) ≥ 1.5; VMicro (cm3/g) ≥ 0.5) NPCMs. Moreover, it was observed that a narrow pore size distribution (0.5-2.0 nm) yields excellent results in the remediation of noxious contaminants. Further, chemical activating agents such as NaOH, KOH, ZnCl2, and H3PO4 were compared. It was observed that activating agents KОН, H3PO4, and ZnCl2 were generally used and played a significant role in the possible large-scale production and commercialization of NPCMs. Thus, it can be interpreted that with a well-planned strategy for the synthesis, NPCMs with a "tuned" porosity for a specific application, in particular, microporosity for the accumulation and adsorption of energetically important gases (CO2, CH4, H2), micro-mesoporosity and mesoporosity for high adsorption capacity for towards metal ions and a large number of dyes, respectively.

Superior photocatalytic and electrochemical activity of novel WS2/PANI nanocomposite for the degradation and detection of pollutants: Antibiotic, heavy metal ions, and dyes

The untreated discharge of noxious pollutants is drawing worldwide concern due to their irretrievable damage to the environment. Especially, pharmaceutical waste has been identified as an emerging pollutant due to its increased demand and untreated discharge into the water bodies. The elimination and detection of such persistent contaminants from wastewater have proven to be a difficult endeavor due to the constraints imposed by the materials and technologies. Therefore, in the present work “free two birds with one key” strategy was implemented to develop a novel visible-light-driven photocatalyst and the electrochemical sensor using WS2/PANI nanocomposite for the degradation and detection. The synthesized WS2/PANI nanocomposite was systematically characterized with a High-resolution transmission electron microscope (HRTEM) and Field emission scanning electron microscope (FESEM) for morphology, Energy-dispersive X-ray (EDX) spectroscopy for elemental analysis, X-ray diffractogram (XRD) for orientation planes, Fourier transform infrared (FTIR) spectroscopy for functional groups and bonds, Zeta potential for the surface charge, Tauc's plot for bandgap analysis, Photoluminescence (PL) spectroscopy study for defects, Time-Resolved Photoluminescence (TRPL) for photogenerated charge carriers, BET for surface parameters and Liquid chromatography-mass spectrometry (LC-MS) for intermediate photodegradation products. The WS2/PANI nanocomposite displayed excellent activity for the photodegradation of antibiotic (nitrofurantoin: NFT, 95%) along with the detection and also degraded textile dye (Methyl orange: MO, 97%), and heavy metal ion (Cr(VI), 99%) with good reusability up to 4 cycles. The superior photocatalytic activity demonstrated by WS2/PANI attributes to its remarkable properties such as a high photoinduced charge separation (5.76 ns) and visible-light-driven bandgap (2.6 eV). A scavenger experiment was also performed to confirm the formation of photoinduced reactive oxygen species (•OH and O2•−). In addition to photocatalytic degradation, WS2/PANI nanocomposite portrayed excellent electrochemical detection of NFT with a low limit of detection (LOD) of 0.01 µM and a wide linear range of 500–0.01 µM.

Metal-Doped Graphitic Carbon Nitride Nanomaterials for Photocatalytic Environmental Applications-A Review.

In the current world situation, population and industrial growth have become major problems for energy and environmental concerns. Extremely noxious pollutants such as heavy metal ions, dyes, antibiotics, phenols, and pesticides in water are the main causes behind deprived water quality leading to inadequate access to clean water. In this connection, graphite carbon nitride (GCN or g-C3N4) a nonmetallic polymeric material has been utilized extensively as a visible-light-responsive photocatalyst for a variety of environmental applications. This review focuses on recent developments in the design and photocatalytic applications of metal-doped GCN-based nanomaterials in CO2 photoreduction, water splitting toward hydrogen production, bacterial disinfection, and organic pollutant degradation. Additionally, this review discusses various methods of using GCN-based materials to optimize dye sensitization, metal deposition, ion doping, and their environmental applications.