Bioengineered sustainable phytofabrication of anatase TiO2 -adorned g-C3N4 nanocomposites and unveiling their photocatalytic potential towards advanced environmental remediation.

The ecologically friendly properties, low-cost, and readily available titanium dioxide (TiO2) materials have made them a subject of considerable interest for numerous promising applications. Anatase TiO2 nanoparticles were synthesized in the current study through the utilization of a hibiscus leaf extract and the advent of TiO2-doped g-C3N4(TiCN) nanocomposites (varying 0.5 mM, 1.0 mM, 1.5 mM, and 2.0 mM) by thermal polymerization. Here, the proposed study utilized multiple analytical techniques, including UV-Vis spectroscopy, a diffraction pattern (XRD), SEM coupled with EDX analysis, TGA, and EPR, to characterize the as-prepared TiO2 nanoparticles and TiCN nanocomposites. BET analysis the adsorption-desorption isotherms of the TiCN(1.5 mM) nanocomposite, the surface area of the prepared nanocomposite is 112.287 m2/g, and the pore size is 7.056 nm. The XPS spectra support the development of the TiCN(1.5 mM) nanocomposite by demonstrating the presence of C and N elements in the nanocomposite in addition to TiO2. HRTEM images where the formation of stacked that indicates a planar, wrinkled graphitic-like structure is clearly visible. The TiCN (1.5 mM) specimen exhibited enhanced morphology, enhanced surface area, greater capacity to take in visible light, and lowered band gap when compared to g-C3N4 following z-scheme heterojunction. The sample denoted as TiCN (1.5 mM) exhibited superior performance in terms of adsorption and photocatalytic activity using rhodamine B and Bisphenol A. Furthermore, the TiCN (1.5 mM) composite exhibited satisfactory stability over four cyclic runs, indicating its potential application in minimizing the impact of organic wastewater contaminants when compared to g-C3N4.

Unleashing the visible light-exposed photocatalytic potential of V2O5/g-C3N4 nanocomposites for dye industries wastewater cleaner production.

Dealing harmful dye-containing effluent from the textile sector significantly contributes to water contamination. The persistence of these dyes in wastewater complicates traditional treatment approaches, emphasizing the necessity for efficient photocatalytic materials for dye pollution degradation. Due to its unique features, V2O5/g-C3N4 nanocomposites are discovered as promising photocatalysts in this area. The V205 nanoparticles act as electron acceptors, while g-C3N4 acts as electron donors, thus encouraging charge separation and increasing photocatalytic activity. The V2O5/g-C3N4 nanocomposites are characterized using XRD, FTIR spectroscopy, SEM, TEM, XPS, and UV-DRS. Cationic dyes, anionic dyes and mix dyes (1:1 mixture of cationic and anionic dyes) are used to test the photocatalytic activity of the nanocomposites. Photocatalytic activity shows that V2O5/g-C3N4 nanocomposites are more active than their precursors. The V5G-2 nanocomposite degrades anionic (Rose Bengal (85.1%) and Xylenol Orange (77.6%), cationic (Auramine O (75% and Crystal Violet (79.5%), and mixed dyes (81%), after 120 min of irradiation. This study introduces a novel technique for synthesizing V2O5/g-C3N4 nanocomposites using solvothermal and ultrasonic processes. The findings of this research provide significant knowledge for the development of photocatalysts with enhanced efficiency in the degradation of dye pollutants.

Eco-friendly phytofabrication of Ficus Benjamina L. based ZnO-doped g-C3N4 nanocomposites for remarkable photocatalysis and antibacterial applications.

The research reported here emphasizes the phytoextract route synthesized ZnO-doped g-C3N4 (GCN) for its photocatalytic activity, which helps to ensure a sustained & healthy environment. The leaf extract solution of Ficus Benjamina L. was used for the synthesis of ZnO nanoparticles, and GCN was prepared via urea using a thermal polymerization process. The flower extract functions as both stabilizers and capping agents during the process of synthesis of ZnO nanoparticles. The synthesized nanocomposites were then calcined at 400 °C and were further characterized with spectroscopy (UV-Vis), diffracted pattern (XRD), and infrared spectroscopy (FTIR). Further, the photocatalytic activity of auramine orange (AO) and methylene blue (MB) dye from phytoextract route synthesized pure ZnO NPs, GCN-Pure, and composites with varied millimolar concentrations of ZnO nanoparticles with GCN of the constant amount was checked. After the complete analysis, it was observed that the series that was prepared of ZnO-GCN nanocomposites showed notable enhancement in the degradation pattern of the methylene blue dye. Apparently, 1.5 mmol (mM) ZnO-GCN presented greater degradation patterns for Auramine orange and Methylene blue dye as compared to other nanocomposites that were synthesized. The observed increased photocatalytic activity has a conceivable explanation. The antibacterial activity studies of the prepared nanocomposites were also performed against the E. coli strain showing an enhanced zone of inhibition towards it.

Visible light enhanced photocatalytic degradation of organic pollutants with SiO2/g-C3N4 nanocomposite for environmental applications.

The development of eco-friendly photocatalysts is gaining attention as an effective approach for degrading organic pollutants. In the present study, the composite materials are composed of various components with varying structures that combine to enhance their characteristics and widen their applications. This work uses the hydrothermal method for the fabrication of a novel and steady SiO2/g-C3N4 photocatalyst. The amount of SiO2 was fixed, and graphitic carbon nitride (g-C3N4) was varied in the ratio (1:x, where x = 1, 2, 3) and abbreviated as SCN1, SCN2, and SCN3. The optical properties, surface morphology, and structural analysis of the prepared nanocomposites were studied using various techniques such as FTIR, TGA, X-ray diffraction, and ultraviolet-visible spectroscopy. The results show that SCN2 nanocomposites significantly improved the photocatalytic activity, with a degradation efficiency of 70% for auramine O and 84.6% for xylenol orange dye under visible light irradiation, which is a result of their large surface area and efficient electron-hole separation rate.

Synthesis of phytoextract-mediated Ag-doped graphitic carbon nitride (Ag@GCN) for photocatalytic degradation of dyes.

The present work focuses on the green synthesis of Ag-doped graphitic carbon nitride (Ag@GCN) for photocatalytic activities, which can contribute to a more sustainable environment. The leaf extract of the Ocimum tenuiflorum (Tulsi) plant was used to prepare the silver nanoparticles, as the plant extract serves as a stabilizing and capping agent in producing silver nanoparticles. Both Ag nanoparticles and urea-derived GCN were synthesized by thermal polymerization. The Ag-doped GCN nanocomposites were synthesized using various millimolar concentrations of Ag nanoparticles (NPs) with a fixed amount of GCN. The green nanocomposites (NCs) were synthesized by calcinating leaf extract at about 550 °C. They were then characterized for surface morphology by SEM coupled with energy-dispersive X-ray spectroscopy (EDX), and elemental composition by XRD, Fourier-dispersive infrared spectroscopy (FTIR), and transmission electron microscope (TEM). Thermal stability and estimation of the Ag content in GCN were done through thermogravimetric analysis. The prepared series of nanocomposites (Ag-doped GCN 0.5 mM, 1.0 mM, 1.5 mM, 2.0 mM) were used to study the photocatalytic degradation efficiency of rose bengal (RB) and xylenol orange (XO) dyes. The degradation efficiency of dyes gets enhanced due to the doping of Ag nanoparticles into GCN. The efficiency increased from 54 to 76% and 15 to 36% in the case of RB and XO dyes, respectively. The apparent rate constant value increased up to 2.5 times in the case of the Ag-doped GCN (1.5 mM) nanocomposite in comparison to GCN. The result obtained from the study confirmed that Ag-doped GCN (1.5 mM) could act as a potential photocatalyst for wastewater remediation applications.

Chemistry and buffering capacity of fog water collected in and around New Delhi, India.

In this study, fog water samples collected from New Delhi and its satellite township Sonipat for 2 years 2015-16 and 2016-17 are characterized by soluble ions and internal buffering capacity. The pH of fog water is close to 5.6 due to the limited contributions of Ca2+ and Mg2+ ions by virtue of low wind speed during winters. NH4+ and Ca2+ were dominant cations in fog at both sites during both sampling years. NH4+ and Ca2+ contributions were similar in New Delhi during 2015-16, but Ca2+ increased during 2016-17 on account of construction activities. Emissions from agriculture fields through fertilizer applications and animal breeding lead to an increase of NH4+ compared to Ca2+ at Sonipat. SO42- was comparable with Cl-, followed by NO3- ions. Plastic burning in this region during wintertime was a possible source of Cl- ions. Acid neutralization decreases as NH4+ > Ca2+ and Mg2+ for all samples in Sonipat and as Ca2+ > NH4+ and Mg2+ in New Delhi. Higher NO3- in New Delhi was due to vehicular emissions. Vehicular emissions in New Delhi and agriculture fields in Sonipat were dominant sources of organic acids. Observed internal buffering capacity was different than theoretical values over a pH range from 4 to 7 in New Delhi, whereas both buffering capacities were close to each other in Sonipat samples. Lead in fog water at both sites was higher than prescribed safe limits for drinking water. Pollution sources were responsible for higher concentrations of metals, organic acids, and soluble ions in fog in New Delhi compared to that in Sonipat.

Photocatalytic dye degradation and antibacterial activities of CeO2/g-C3N4 nanomaterials for environmental applications.

The uncontrolled dumping of synthetic dyes into water sources has posed severe hazards to the ecosystem. For decades, several materials with low cost and high efficiency have been investigated for dye degradation. Photocatalytic degradation is regarded as a successful strategy since it utilizes sunlight to transform harmful pollutants into nontoxic compounds without using oxidative agents. The photocatalytic potentials of CeO2/g-C3N4 (CG) were investigated in this work using a simplistic ultrasonication process. Here, the amount of CeO2 was fixed, and g-C3N4 was varied in the ratio (1:x, where x = 1, 2, and 3) and abbreviated as CG1, CG2, and CG3. Characterization techniques such as Fourier transforms-infrared spectroscopy, thermal gravimetric analysis (TGA), powdered X-ray diffraction, ultraviolet-visible spectroscopy, etc. were used to characterize structural analysis, optical properties, particle size, and chemical bonds of the prepared nanocomposites. The photocatalytic results showed that CG2 effectively degraded rose bengal (RB) and crystal violet (CV) dyes when exposed to visible light irradiation as compared to pure GCN and CeO2. The antibacterial activity analysis further supported the potential application of prepared photocatalyst as a disinfectant agent against both gram-positive (Staphylococcus aureus and Bacillus cereus) and gram-negative (Salmonella abony and Escherichia coli) pathogenic strains of bacteria.

Air Quality Before and After COVID-19 Lockdown Phases Around New Delhi, India.

BACKGROUND: The COVID-19 pandemic has had a deep global impact, not only from a social and economic perspective, but also with regard to human health and the environment. To restrict transmission of the virus, the Indian government enforced a complete nationwide lockdown except for essential services and supplies in phases from 25 March to 31 May 2020. Ambient air quality in and around New Delhi, one of the most polluted cities of world, was also impacted during this period. OBJECTIVE: The aim of the present study was to assess and understand the impact of four different lockdown phases (LD1, LD2, LD3 and LD4) on five air pollutants (particulate matter (PM) PM2.5, PM10, nitrogen oxide (NOx), sulfur dioxide (SO2) and ozone (O3)) compared to before lockdown (BLD) at 13 air monitoring stations in and around New Delhi. METHODS: Secondary data on five criteria pollutants for 13 monitoring stations in and around New Delhi for the period 1 March to 31 May 2020 was accessed from the Central Pollution Control Bard, New Delhi. Data were statistically analyzed across lockdown phases, meteorological variables, and prevailing air sources around the monitoring stations. RESULTS: Pollutant concentrations decreased during LD1 compared to BLD except for O3 at all stations. PM2.5 and PM10 remained either close to or higher than the National Ambient Air Quality Standards (NAAQS) due to prevailing high-speed winds. During lockdown phases, NO2 decreased, whereas O3 consistently increased at all stations. This was a paradoxical situation as O3 is formed via photochemical reactions among NOx and volatile organic compounds. Principal component analysis (PCA) extracted two principal components (PC1 and PC2) which explained up to 80% of cumulative variance in data. PM2.5, PM10 and NO2 were associated with PC1, whereas PC2 had loadings of either O3 only or O3 and SO2 depending upon monitoring station. CONCLUSIONS: The present study found that air pollutants decreased during lockdown phases, but these decreases were specific to the site(s) and pollutant(s). The decrease in pollutant concentrations during lockdown could not be attributed completely to lockdown conditions as the planetary boundary layer increased two-fold during lockdown compared to the BLD phase. Such restrictions could be applied in the future to control air pollution but should be approached with caution. COMPETING INTERESTS: The authors declare no competing financial interests.

Fast removal of heavy metals from water and soil samples using magnetic Fe3O4 nanoparticles.

Heavy metal discharge from anthropogenic sources on open soil surfaces and in natural water bodies poses serious environmental and health concerns. In addition to the contamination reduction of metals at the source, post-discharge removal of metals using nanoparticles is one of the remediation technologies being explored nowadays due to its cost-effectiveness, being environment-friendly, and easy application as a technique. In this work, magnetic iron oxide (Fe3O4) nanoparticles were synthesized chemically and then used for the removal of heavy metals (Cd, Cr, Cu, Fe, Ni, Pb, and Zn) from water and soil samples. The heavy metal removal efficiency of these iron oxide nanoparticles for different metals in water was best observed at a pH of 4.5 and varied between 63.5 and 98.3%. However, the removal efficiency of these nanoparticles from the soil sample was only measured at a pH of 0.7, and heavy metal removal efficiency varied between 69.6 and 99.6%. In both soil and water samples, the most efficient remediation time was less than 20 min, after which desorption and even dissolution of the nanoparticles can occur at a highly acidic pH. Among all selected metals for removal, lead showed the best adsorption and hence removal efficiency. The nanoparticles were characterized using the TEM, XRD, and FTIR techniques. The adsorption efficiency of various metals was estimated by using atomic absorption spectroscopy. The results suggest that the removal efficiency and stability of adsorbed products can further be improved by adjusting the pH higher towards 7 and also perhaps by modifying the nanoparticles with functional groups. The primary advantage of the magnetic un-coated nanoparticles is easy and efficient removal of the nanoparticles from the treated solutions by using an ordinary magnet.

Removal of organic dyes from wastewater using Eichhornia crassipes: a potential phytoremediation option.

Wastewater from textile industries is a potential source of organic dyes in natural water bodies. Environmental concerns of chemical methods for removal of dyes from wastewater are no more a viable solution, and there is growing concern to develop alternative approaches such as green chemistry and phytoremediation. This study reports the removal of organic dyes from wastewater using Eichhornia crassipes (Mart.) Solms (water hyacinth), as an easily available and fast-growing plant species. Growth of water hyacinth among individual cationic (rose bengal (RB), methylene blue (MB), crystal violet (CV), auramine O (AO), rhodamine B (RhB) and anionic (xylenol orange (XO), phenol red (PR), cresol red (CR), methyl orange (MO)) dye solutions and degradation of dyes were monitored. Results indicated that water hyacinth has good absorption and degradation potential for both types of dyes (cationic or anionic) and effectively removes dyes from solution. Water hyacinth can be used as a suitable and effective phytoremediate for removal of organic dyes from the wastewater.Graphical abstract.

An Innovative Method for Iris Positioning in a Prosthetic Eye.

AIM: An apparatus named "laser pointer apparatus" is proposed for accurate iris positioning in a prosthetic eye. BACKGROUND: Loss of an eye leads to significant psychological stress due to functional disability and societal response to the facial disablement. Custom-made eye prosthesis is a good option to rehabilitate such defects. Inaccurately positioned iris in a prosthetic eye results in squint eye appearance leading to poor esthetics and poor psychological impact among such unfortunate patients. TECHNIQUE: A new apparatus called a laser pointer apparatus, which is an assembly of an occlusal plane analyzer, web camera, laser pointer, and software, has been introduced for iris positioning in a prosthetic eye. CONCLUSION: Iris positioning is one of the key steps in fabricating an eye prosthesis. Laser pointer apparatus is a reliable method for iris positioning in a prosthetic eye. CLINICAL SIGNIFICANCE: Positioning the iris to the ideal symmetrical position is a cardinal step in the fabrication of an ocular prosthesis. This article aims to introduce a "laser pointer apparatus" to orient iris in a prosthetic eye objectively to overcome the subjective errors.

Review of drug treatment of oral submucous fibrosis.

This study undertook a review of the literature on drug treatment of oral submucous fibrosis. An electronic search was carried out for articles published between January 1960 to November 2011. Studies with high level of evidence were included. The levels of evidence of the articles were classified after the guidelines of the Oxford Centre for Evidence-Based Medicine. The main outcome measures used were improvement in oral ulceration, burning sensation, blanching and trismus. Only 13 publications showed a high level of evidence (3 randomized controlled trials and 10 clinical trials/controlled clinical trials), with a total of 1157 patients. Drugs like steroids, hyaluronidase, human placenta extracts, chymotrypsin and collagenase, pentoxifylline, nylidrin hydrochloride, iron and multivitamin supplements including lycopene, have been used. Only systemic agents were associated with few adverse effects like gastritis, gastric irritation and peripheral flushing with pentoxifylline, and flushingly warm skin with nylidrin hydrochloride; all other side-effects were mild and mainly local. Few studies with high levels of evidence were found. The drug treatment that is currently available for oral submucous fibrosis is clearly inadequate. There is a need for high-quality randomized controlled trials with carefully selected and standardized outcome measures.