Optimized Cu-doping in ZnO electro-spun nanofibers for enhanced photovoltaic performance in perovskite solar cells and photocatalytic dye degradation.

Perovskite solar cells (PSCs) compete with conventional solar cells regarding their low-temperature processing and suitable power conversion efficiency. In PSCs, the electron transport layer (ETL) plays a vital role in charge extraction and avoiding recombination; however, poor charge transport of ETL leads to high internal resistance and associated low fill factors. To successfully resolve this challenge, copper-doped zinc oxide nanofibers as an electron transport layer are prepared with various doping levels of 1, 2, and 3 wt% using the electrospinning sol-gel method. The 3 wt% doping of Cu revealed the optimum performance as an ETL, as it offers an electrically efficient transporting structure. SEM images revealed a randomly oriented distribution of nanofibers with different sizes having mesoporous uniformity. Optical properties of doped nanofibers examined using UV-visible analysis showed an extended light absorption due to heteroatom-doping. Adding Cu into the ZnO leads to enhanced charge mobility across the electron transport material. According to Hall measurements, dopant concentration favors the conductivity and other features essentially required for charge extraction and transport. The solar cell efficiency of ZnO doped with 0%, 1%, 2%, and 3% Cu is 4.94%, 5.97%, 6.89%, and 9.79%, respectively. The antibacterial and photocatalytic activities of the prepared doped and undoped ZnO are also investigated. The better light absorption of Cu-ZnO showed a pronounced improvement in the photocatalytic activity of textile electrodes loaded with doped ZnO. The dye degradation rate reaches 95% in 180 min under visible light. In addition, these textile electrodes showed strong antibacterial activity due to the production of reactive oxygen species under light absorption.

Synthesis of hydrazone-based polyhydroquinoline derivatives - antibacterial activities, α-glucosidase inhibitory capability, and DFT study.

In recent years, polyhydroquinolines have gained much attention due to their widespread applications in medicine, agriculture, industry, etc. Here, we synthesized a series of novel hydrazone-based polyhydroquinoline derivatives via multi-step reactions. These molecules were characterized by modern spectroscopic techniques (1H-NMR, 13C NMR, and LC-HRMS) and their antibacterial and in vitro α-glucosidase inhibitory activities were assessed. Compound 8 was found to be the most active inhibitor against Listeria monocytogenes NCTC 5348, Bacillus subtilis IM 622, Brevibacillus brevis, and Bacillus subtilis ATCC 6337 with a zone of inhibition of 15.3 ± 0.01, 13.2 ± 0.2, 13.1 ± 0.1, and 12.6 ± 0.3 mm, respectively. Likewise, compound 8 also exhibited the most potent inhibitory potential for α-glucosidase (IC50 = 5.31 ± 0.25 µM) in vitro, followed by compounds 10 (IC50 = 6.70 ± 0.38 µM), and 12 (IC50 = 6.51 ± 0.37 µM). Furthermore, molecular docking and DFT analysis of these compounds showed good agreement with experimental work and the nonlinear optical properties calculated here indicate that these compounds are good candidates for nonlinear optics.

Reinforcement using undoped carbon quantum dots (CQDs) with a partially carbonized structure doubles the toughness of PVA membranes.

Nano-carbon-reinforced polymer composites have gained much consideration in functional applications due to their attractive mechanical strength and cost-effectiveness. The surface chemistry and associated mechanical strength of carbon nanotubes (CNTs), graphene, and other carbon derivative-based nanocomposites are well understood. While CQDs are considered emerging carbon derivatives, their surface chemistry, unique physio-chemical properties, and dispersion behavior in polymers are yet to be explored. Therefore, in this work, CQDs with different structures were synthesized from lemon pulp and urea, and their rheology and mechanical strength were studied in the PVA matrix. The surface chemistry and structure of CQDs were controlled using different solvents and reaction temperatures, respectively. CQDs possessed a circular shape, with a size of <10 nm, having a suitable carbon core and functional groups, as confirmed by TEM and FTIR spectroscopy. The dynamic viscosity and particle size of PVA/CQDs films peaked at 4% inclusion due to the maximum crosslinking of U-CQDs with reinforcement at 180 °C. Compared with pure PVA, the optimized composite showed an 80% larger particle size with 67% better tensile strength at 4% U-CQDs concentration. In addition to enhanced mechanical strength, CQDs exhibited antibacterial activity in composites. These CQDs-reinforced PVA composites may be suitable for different functional textile applications (shape memory composites and photo-active textiles).

Novel hydrazone schiff's base derivatives of polyhydroquinoline: synthesis, in vitro prolyl oligopeptidase inhibitory activity and their Molecular docking study.

This research work reports the synthesis of new derivatives of the hydrazone Schiff bases (1-17) based on polyhydroquinoline nucleus through multistep reactions. HR-ESIMS,1H- and 13C-NMR spectroscopy were used to structurally infer all of the synthesized compounds and lastly evaluated for prolyl oligopeptidase inhibitory activity. All the prepared products displayed good to excellent inhibitory activity when compared with standard z-prolyl-prolinal. Three derivatives 3, 15 and 14 showed excellent inhibition with IC50 values 3.21 ± 0.15 to 5.67 ± 0.18 µM, while the remaining 12 compounds showed significant activity. Docking studies indicated a good correlation with the biochemical potency of compounds estimated in the in-vitro test and showed the potency of compounds 3, 15 and 14. The MD simulation results confirmed the stability of the most potent inhibitors 3, 15 and 14 at 250 ns using the parameters RMSD, RMSF, Rg and number of hydrogen bonds. The RMSD values indicate the stability of the protein backbone in complex with the inhibitors over the simulation time. The RMSF values of the binding site residues indicate that the potent inhibitors contributed to stabilizing these regions of the protein, through formed stable interactions with the protein. The Rg. analysis assesses the overall size and compactness of the complexes. The maintenance of stable hydrogen bonds suggests the existence of favorable binding interactions. SASA analysis suggests that they maintained stable conformations without large-scale exposure to the solvent. These results indicate that the ligand-protein interactions are stable and could be exploited to design new drugs for disease treatment.Communicated by Ramaswamy H. Sarma.

Correction: Carbon quantum dots (CQDs)-modified polymers: a review of non-optical applications.

Correction for 'Carbon quantum dots (CQDs)-modified polymers: a review of non-optical applications' by Zeeshan Latif et al., Nanoscale, 2024, 16, 2265-2288, https://doi.org/10.1039/D3NR04997C.

Synthesis, biochemical and computational evaluations of novel bis-acylhydrazones of 2,2'-(1,1'-biphenyl)-4,4'-diylbis(oxy))di(acetohydrazide) as dual cholinesterase inhibitors.

A series of twenty-seven bis(acylhydrazones) were successfully synthesized with high yields through a multistep process, which entailed the esterification of hydroxyl groups, hydrazination with an excess of hydrazine hydrate, and subsequent reactions with various carbonyl moieties (aldehydes). In the final stage of synthesis, different chemical species including aromatic, heterocyclic, and aliphatic compounds were integrated into the framework. The resulting compounds were characterized using several spectroscopic techniques (1H NMR, 13C NMR, and mass spectrometry). Their anticholinesterase activities were assessed in vitro by examining their interactions with two cholinesterase enzymes: acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). Among the synthesized hits, compounds 3, 5, 6, 9-12, and 14 exhibited good to moderate inhibition of AChE. Specifically, 10 (IC50 = 26.3 ± 0.4 µM) and 11 (IC50 = 28.4 ± 0.5 µM) showed good inhibitory activity against AChE, while 9, 12, 3, and 6 exhibited significant inhibition potential against AChE with IC50 values ranging from 35.2 ± 1.1 µM to 64.4 ± 0.3 µM. On the other hand, 5 (IC50 = 22.0 ± 1.1 µM) and 27 (IC50 = 31.3 ± 1.3 µM) displayed significant, and 19 (IC50 = 92.6 ± 0.4 µM) showed moderate inhibitory potential for BChE. Notably, 5 and 27 exhibited dual inhibition of AChE and BChE, with greater potency than the standard drug galantamine. The binding patterns of these molecules within the binding cavities of AChE and BChE were anticipated by molecular docking which showed good correlation with our in vitro findings. Further structural optimization of these molecules may yield more potent AChE and BChE inhibitors.

Carbon quantum dots (CQDs)-modified polymers: a review of non-optical applications.

Carbon quantum dots (CQDs) are a promising candidate to replace metal-based additives for polymer reinforcement and functionalization. Specifically, vast interest in CQDs for polymer functionalization stems from their cost effectiveness, sustainable organic precursors, and their non-toxicity. Although several reviews of optical devices based on CQDs have been reported, this mini-review covers the non-optical aspects of CQD-polymer composites. Applications of CQD-modified polymers for smart devices, mechanical reinforcement, textile surface-modification methods, membranes, protective coatings, and thermal resistance are summarized. The synthesis method of CQDs, their dispersion in a polymer matrix and the underlying mechanisms related to the enhanced performance of composites are outlined. Unlike nano-reinforcements, CQDs are self-stabilized and offer an extremely high surface area, which significantly alters the polymer properties at a 1-2% concentration. Finally, a comparative analysis of recent advances in CQD-polymer composites, their problems, and future directions are discussed.

Facile-Solution-Processed Silicon Nanofibers Formed on Recycled Cotton Nonwovens as Multifunctional Porous Sustainable Materials.

Limited efficiency, lower durability, moisture absorbance, and pest/fungal/bacterial interaction/growth are the major issues relating to porous nonwovens used for acoustic and thermal insulation in buildings. This research investigated porous nonwoven textiles composed of recycled cotton waste (CW) fibers, with a specific emphasis on the above-mentioned problems using the treatment of silicon coating and formation of nanofibers via facile-solution processing. The findings revealed that the use of an economic and eco-friendly superhydrophobic (contact angle higher than 150°) modification of porous nonwovens with silicon nanofibers significantly enhanced their intrinsic characteristics. Notable improvements in their compactness/density and a substantial change in micro porosity were observed after a nanofiber network was formed on the nonwoven material. This optimized sample exhibited a superior performance in terms of stiffness, surpassing the untreated samples by 25-60%. Additionally, an significant enhancement in tear strength was observed, surpassing the untreated samples with an impressive margin of 70-90%. Moreover, the nanofibrous network of silicon fibers on cotton waste (CW) showed significant augmentation in heat resistance ranging from 7% to 24% and remarkable sound absorption capabilities. In terms of sound absorption, the samples exhibited a performance comparable to the commercial standard material and outperformed the untreated samples by 20% to 35%. Enhancing the micro-roughness of fabric via silicon nanofibers induced an efficient resistance to water absorption and led to the development of inherent self-cleaning characteristics. The antibacterial capabilities observed in the optimized sample were due to its superhydrophobic nature. These characteristics suggest that the proposed nano fiber-treated nonwoven fabric is ideal for multifunctional applications, having features like enhanced moisture resistance, pest resistance, thermal insulation, and sound absorption which are essential for wall covers in housing.

Novel benzimidazole derivatives as effective inhibitors of prolyl oligopeptidase: synthesis, in vitro and in silico analysis.

Background: This research aims to discover novel derivatives having potential therapeutic applications in treating conditions related to prolyl oligopeptidase (POP) dysfunction. Method: Novel benzimidazole derivatives have been synthesized, characterized and screened for their in vitro POP inhibition. Results: All these derivatives showed excellent-to-good inhibitory activities in the range of IC50 values of 3.61 ± 0.15 to 43.72 ± 1.18 µM, when compared with standard Z-prolyl-prolinal. The docking analysis revealed the strong interactions between our compounds and the target enzyme, providing critical insights into their binding affinities and potential implications for drug development. Conclusion: The significance of these compounds in targeting POP enzyme offers promising prospects for future research in the field of neuropharmacology.

Polyhydroquinoline derivatives for diabetic management: synthesis, in vitro and in silico approaches.

Background: Medication used to treat Type 2 diabetes by decreasing the absorption of carbohydrates in the intestine consists of α-glucosidase inhibitors. Polyhydroquinoline derivatives have attracted interest as excellent antidiabetic agents. Methods: Polyhydroquinoline derivatives (1-17) were synthesized and tested for in vitro α-glucosidase inhibitory activity. Results: All the synthesized compounds exhibited excellent to good inhibitory activity, having IC50 values from 1.23 ± 0.03 to 73.85 ± 0.61 µM, compared with the standard drug, acarbose. The binding mechanism of these derivatives with α-glucosidase was deduced by docking studies and indicated that a slight variation in the orientation of compounds, affects their binding capability. Conclusion: In order to find new antidiabetic drugs, this study has discovered prospective lead candidates.

Direct Growth of Nitrogen-Doped Carbon Quantum Dots on Co9S8 Passivated on Cotton Fabric as an Efficient Photoelectrode for Water Treatment.

Heterogeneous growth of photocatalysts on different porous substrates is a solution to avoid secondary pollution caused by composite photocatalysts themselves. However, the heterogeneous growth of composite photocatalysts with nitrogen-doped carbon quantum dots (NCQDs) inclusions-introduced during synthesis-impedes the direct growth on the substrate. To overcome this problem, NCQDs were grown on a Co9S8 (NCQDs-G@Co9S8) layer, decorated on cotton fabric. This optimal coupling mode of NCQDs and Co9S8 showed 54% degradation, compared to 33% dye degradation via NCQDs-doped Co9S8 (NCQDs-D@Co9S8). The change in the crystal structure and its lower loading on fabric results in significantly lower performance of NCQDs-D@Co9S8. Even with the combination of both surface growth and doping (NCQDs-DG@Co9S8), the performance was still limited to 42%. In addition, the optimum growth concentration of NCQDs on Co9S8 was observed for 7.5 w/w %, resulting in 92% photocatalytic activity (PCA) in 80 min. Comparing different surface states formed in NCQDs using different solvents, water-based surface states (oxygen-rich surface) are most suitable for the dye degradation. NCQDs-G@Co9S8 also offers 67% Cr-VI reduction to Cr-III, showing its suitability for both inorganic and organic compounds. Better electrode performance was related to suitable charge separation of the composite, where -OH groups mainly contribute in the photocatalytic dye degradation..

Evaluation of Organic and Inorganic Foulant Interaction Using Modified Fouling Models in Constant Flux Dead-End Operation with Microfiltration Membranes.

The goal of this study was to elucidate the interaction of complex feed solutions under modified membrane fouling models for constant flux operation. The polyvinylidene fluoride membrane (PVDF) was tested for three types of solutions containing inorganic foulants (Al, Mn, and Fe), organic foulants, and suspended solids at 0.5 mM Ca2+ ionic strength. The membrane's performance was evaluated by measuring the increase in transmembrane pressure (TMP) during two different filtration scenarios: continuous filtration lasting 1 h and cyclic filtration lasting 12 min, with 3 min backwashing cycles included. Statistical analysis (linear regression results (R2), p-value) was used to verify the fouling model propagation along with the determination of the contributing constant of each fouling model. An increasing TMP percentage of 164-302%, 155-300%, and 208-378% for S1 (HA + Ca2+), S2 (inorganics + kaolin + Ca2+), and S3 (HA + inorganics + kaolin + Ca2+) was recorded for 1 h filtration, respectively. Furthermore, a five percent increase in irreversible resistance was noted for the S3 solution due to the strong adsorption potential of foulants for the PVDF membrane caused by the electrostatic and hydration forces of foulants. In addition to that, the participation equation elucidated the contribution of the fouling model and confirmed that complete blocking and cake layer contribution were dominant for the S1 and S3 solutions, while standard blocking was dominant for the S2 solution with a high significance ratio. Moreover, R2 and cyclic filtration analysis also confirmed the propagation of these fouling models. The statistical confirmation and regression results analysis of the modified model gave comparative results and satisfied the filtration mechanism and can be used for the constant flux dead filtration analysis of water treatment.

Discovery of (S)-flurbiprofen-based novel azine derivatives as prostaglandin endoperoxide synthase-II inhibitors: Synthesis, in-vivo analgesic, anti-inflammatory activities, and their molecular docking.

The anti-inflammatory and analgesic drugs currently used are associated with several adverse effects and found to be highly unsafe for long-term use. Currently, nineteen novel bis-Schiff base derivatives (1-19) of flurbiprofen have been designed, prepared and assessed for in-vivo analgesic, anti-inflammatory and in vivo acute toxicity evaluation. The structures of the acquired compounds were deduced through modern spectroscopic techniques including HR-ESI-MS, 13C-, and 1H NMR. Amongst the series, compounds 7, 9, and 10 attributed potent activities with 93.89, 92.50, and 90.47% decreased edema, respectively compared to flurbiprofen (90.01%), however, compounds 11 and 15 exhibited significant activity of 90.00% decrease. Out of them, fourteen compounds (1-6, 8, 12-14, and 16-19) displayed good activity in the range of 68.96-86.95%. In case of an analgesic study, all the derivatives significantly (p 0.001) increased the pain threshold time particularly compound 7 had the best analgesic effect (24 ± 2.08 s) in comparison with flurbiprofen (21.66 ± 2.02 s) using hot plate test. Similarly, in the acetic acid-induced writhing test, compound 7 determined a potent inhibitory effect (60.47 %) close to flurbiprofen (59.28%). All the synthesized derivatives were found safe up to the dose of 30 mg/kg, in acute toxicity study. On a molecular scale, the synthesized compounds were modeled through a ligand-based pharmacophore study and molecular docking to have insight into the different possible interactions leading to high inhibition levels against the COX-2 enzyme.

Hierarchical NiCo@NiOOH@CoMoO4 Core-Shell Heterostructure on Carbon Cloth for High-Performance Asymmetric Supercapacitors.

The fabrication of low-cost, effective, and highly integrated nanostructured materials through simple and reproducible methods for high-energy-density supercapacitors is highly desirable. Herein, an activated carbon cloth (ACC) is designed as the functional scaffold for supercapacitors and treated hydrothermally to deposit NiCo nanoneedles working as internal core, followed by a dip-dry coating of NiOOH nanoflakes core-shell and uniform hydrothermal deposition of CoMoO4 nanosheets serving as an external shell. The structured core-shell heterostructure ACC@NiCo@NiOOH@CoMoO4 electrode resulted in exceptional specific areal capacitance of 2920 mF cm-2 and exceptional cycling stability for 10 000 cycles. Moreover, the fabricated electrode is developed into an asymmetric supercapacitor which demonstrates excellent areal capacitance, energy density, and power density within the broad potential window of 1.7 V with a cycling life of 92.4% after 10 000 charge-discharge cycles, which reflects excellent cycle life. The distinctive core-shell structure, highly conductive substrate, and synergetic effect of coated material results in more electrochemical active sites and flanges for effective electrons and ion transportation. This unique technique provides a new perspective for cost-efficient supercapacitor applications.

New supramolecules of bis(acylhydrazones)-linked bisphenol sulfide for Alzheimer's: targeting cholinesterases by in vitro and in silico approaches.

In current research, two functional components, i.e., hydrazone and bisphenol sulfide were combined to get useful supramolecules in medicinal chemistry. Herein 25 new 4,4'-thiodiphenol bis-acylhydrazones were synthesized in good to excellent yields. Initially ethyl-2-chloroacetate was reacted with 4,4'-thiodiphenol, which was further reacted with excess hydrazine hydrate to produce 2,2'-((thiobis(4,1-phenylene))bis(oxy))di(acetohydrazide), which was then combined with various aromatic and aliphatic aldehydes to get the desired products (hydrazones, 4a-4y). The synthesized supramolecules were characterized by contemporary spectroscopic techniques such as 1H NMR, 13C NMR, and mass spectroscopy. The synthetic compound's cholinesterase blocking activity was tested against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes where compounds 4n, and 4h showed excellent inhibitory potential for AChE, while 4b, and 4h, demonstrated most potent inhibition of BChE. The starting compound (SM3) and compounds 4h and SM3 depicted excellent dual inhibitory capabilities for both enzymes. The chemical basis of anticholinesterase activity was investigated using a structure-based molecular docking approach. The biological significance and the ease of synthesis of this class of compounds should be considered in therapeutic development for Alzheimer's disease treatments.

Russia-Ukraine war impacts on climate initiatives and sustainable development objectives in top European gas importers.

Russia holds the position of being the third largest global producer of oil and plays a significant role in the supply of oil and gas to Europe. The ongoing war conflict has the potential to impede the bilateral and multilateral relations between Russia and Europe. The ramifications of this event will have notable reverberations for environmental endeavors in Europe. The aforementioned premise forms the basis of our investigation, wherein we scrutinize the correlation among oil price, coal price, gas price, economic growth, and coal consumption, while taking into account the ramifications of the Russian-Ukrainian conflict. We adopted fully "modified ordinary least square (FMOLS), dynamic ordinary least square (DOLS), and canonical cointegration regression (CCR)" econometric techniques to gauge the nexus between factors of interest in the top 4 European Russian gas importer economies (Poland, Netherland, Hungry, and Germany). The empirical outcomes reveal substantial negative impact of economic growth and coal price elasticity on the coal consumption. On the contrary, oil and gas price elasticities depict significant positive influence on the coal consumption. Hence, this study concludes that a rise in oil and gas prices leads to an increase in coal consumption, which in turn negatively impacts environmental quality. Furthermore, the occurrence of war has the potential to impede the utilization of coal resources in Netherlands and Hungary. On the other hand, the impact of war is noteworthy and constructive in Poland and Germany. Thus, war results ecological imbalance in Poland and Germany in particular. Governments, decision-makers, stakeholders, and environmentalists must develop a long-term plan that calls for a paradigm shift away from gas, oil, and coal usage and toward more environmentally benign renewable energy sources.

Do financial development and renewable energy shocks matter for environmental quality: evidence from top 10 emitting emissions countries.

Creating a reliable energy supply, ecological quality, and economic development has become a global effort. Finance is at the center stage ecological transition to low-carbon emission. Against this backdrop, the present work analyses the impact of the financial sector on CO2 emissions using data from the top 10 emitting emissions economies from 1990 to 2018. Using the novel method of moments quantile regression, the findings illustrate that renewable energy usage enhances ecological quality while economic growth lowers it. The results also affirm that financial development is positively linked with carbon emission in the top 10 emitting emissions economies. These results can be explained by the fact that financial development facilities offer low borrowing rates with less restrictions for environmental sustainability projects. The empirical findings of this study highlight the necessity for policies that boost the proportion of clean energy consumption in the top 10 polluting nations' overall energy mix to reduce carbon emissions. It follows that the financial sectors in these nations must invest in cutting-edge energy-efficient technology and clean, green, and environmentally friendly initiatives. This trend will increase productivity, improve energy efficiency, and reduce pollution.

Testing the impact of renewable energy and oil price on carbon emission intensity in China's transportation sector.

As the largest carbon emitter in the world, with its transportation sector contributing the largest shares of its emission, the need for a low-carbon transition economy has become a policy agenda for China because in order to reach carbon neutrality by 2050, lowering the intensity of carbon emissions in the transportation sector will be crucial. In this regard, we used the "bootstrap autoregressive distributed lag model" to explore the impact of clean energy and oil prices on the intensity of carbon emissions in China's transportation sector. The study found that an increase in oil prices decreases the intensity of carbon emissions in the short and long run. Similarly, an increase in the level of renewable energy and economic complexity declines the intensity of carbon emissions in the transportation sector. On the contrary, the research demonstrates that non-renewable energy contributes positively to carbon emission intensity. Therefore, the authorities must promote green technology to neutralize the transportation system's detrimental effects on China's environmental quality. The implications for successfully promoting carbon emission intensity mitigation in the transportation sector are examined in the conclusion.

Do banking sector development, economic growth, and clean energy consumption scale up green finance investment for a sustainable environment in South Asia: evidence for newly developed RALS co-integration.

Concern about climate change is spreading around the globe. The urge to comprehend the environmental effects and take action is sharply rising. Regarding this, the banking industry has a great chance to offer a solution in terms of green financial solutions and can meet the needs of carbon-conscious organizations to combat and defend our planet. Therefore, in light of this, according to the greatest understanding of the authors, this is the first study to investigate the role of banking sector development, economic growth, and clean energy consumption in scaling up green finance investment in South Asian nations, taking carbon emissions, foreign direct investment, remittances, inflation, and trade openness as control variables. This study uses a novel residual augmented least squares-Engle and Granger (RALS-EG) co-integration to test the long-term link and the quantile autoregressive distributed lag (QARDL) econometric approach to extract the association across the quantiles (q0.05-q0.95) for the period 2000-2020. The outcomes of QARDL show that banking sector development, economic growth, clean energy, carbon emissions, foreign direct investment, remittances, and trade openness play a positive role in attracting green finance in the long term. However, only inflation has a negative influence on scaling up finance in South Asian nations. Therefore, the concerned authorities (government, central banks, environmentalists, and policymakers) are urged to implement green finance policies and strategies as suggested and recommended by the results of this study.

Machine learning algorithms for high-resolution prediction of spatiotemporal distribution of air pollution from meteorological and soil parameters.

This study uses machine learning (ML) models for a high-resolution prediction (0.1°×0.1°) of air fine particular matter (PM2.5) concentration, the most harmful to human health, from meteorological and soil data. Iraq was considered the study area to implement the method. Different lags and the changing patterns of four European Reanalysis (ERA5) meteorological variables, rainfall, mean temperature, wind speed and relative humidity, and one soil parameter, the soil moisture, were used to select the suitable set of predictors using a non-greedy algorithm known as simulated annealing (SA). The selected predictors were used to simulate the temporal and spatial variability of air PM2.5 concentration over Iraq during the early summer (May-July), the most polluted months, using three advanced ML models, extremely randomized trees (ERT), stochastic gradient descent backpropagation (SGD-BP) and long short-term memory (LSTM) integrated with Bayesian optimizer. The spatial distribution of the annual average PM2.5 revealed the population of the whole of Iraq is exposed to a pollution level above the standard limit. The changes in temperature and soil moisture and the mean wind speed and humidity of the month before the early summer can predict the temporal and spatial variability of PM2.5 over Iraq during May-July. Results revealed the higher performance of LSTM with normalized root-mean-square error and Kling-Gupta efficiency of 13.4% and 0.89, compared to 16.02% and 0.81 for SDG-BP and 17.9% and 0.74 for ERT. The LSTM could also reconstruct the observed spatial distribution of PM2.5 with MapCurve and Cramer's V values of 0.95 and 0.91, compared to 0.9 and 0.86 for SGD-BP and 0.83 and 0.76 for ERT. The study provided a methodology for forecasting spatial variability of PM2.5 concentration at high resolution during the peak pollution months from freely available data, which can be replicated in other regions for generating high-resolution PM2.5 forecasting maps.