While CuS/TiO₂ has been previously synthesized and employed in a limited number of photodegradation studies, the current study investigated its effectiveness for TC degradation under UV-visible light irradiation. CuS is known to be a nontoxic, environmentally friendly material; hence, it has great potential as an alternative to CdS and CdSe, which are used conventionally as sensitizers. In this work, the CuS/TiO₂ photocatalysts achieved a maximum 95 % removal of TC at an initial concentration of 20 ppm, confirming the good utilization of active sites. Even though the efficiency decreased for higher TC concentrations due to the saturation of the active sites, the values of the quantum yield showed that photon utilization was still effective. Consequently, the photocatalyst showed an optimum yield at 0.20 g, and its further addition increased the efficiency rather insignificantly. In addition to the near-complete mineralization of TC by the CuS/TiO₂ composite with few byproducts, its reusability was excellent because it showed almost consistent performance in successive cycles. These results further confirm the continuous relevance and potential of CuS/TiO₂ as a practical, sustainable solution for organic pollutant degradation, reinforcing its value in environmental remediation applications.

TiO 2 films photo-catalyze S. aureus rupture and mineralization of resulting organic materials.

AbstractClimate change presents a substantial global threat to human health and wellbeing. Planetary health, an emerging field, provides a comprehensive framework to comprehend the intricate interplay between ecological stability, human health, and ecosystems, particularly within the context of climate change. This study investigates the planetary health perspective on climate change by exploring global knowledge. The Scopus database is used as the source of data. The analysis encompassed a performance evaluation aimed at scrutinizing both quantitative and qualitative indicators. Visualization techniques utilizing VOSviewer software were deployed to analyze collaboration patterns, co-citation links among prominent knowledge-sharing platforms, and key topics derived from keyword co-occurrence matrices. Additionally, using SciMAT software, the study conducted thematic evolution and intellectual analyses to identify both driving and emerging themes, while also examining coherence among different themes across various periods. The study also explores policy implications, and the relevance of COVID-19 in the context of planetary health and climate change. Through this analysis, 261 relevant publications are identified, with the United States being the leading contributor (90 documents; 34.5% of publications). At the institutional level, the Australian National University secured the top position, representing 4.6% of the total with 12 documents. The Lancet Planetary Health journal was the most prolific source, contributing 15 documents (5.7%). In terms of impact, The Lancet journal held a central position as the most cited source. The primary funding organization was the Wellcome Trust, based in the United Kingdom. Motor themes shaping the future of this field include vector-borne diseases, human demographics, informal settlements, air pollution, carbon footprint of animal-based foods, and pro-environmental attitudes and behaviors. The study underscores the significance of leveraging the momentum surrounding infectious diseases like COVID-19 and the impacts of climate change to advance planetary health concepts. Integration of the social sciences and enhanced multidisciplinary cooperation are crucial for progress. Additionally, increased funding for developing countries, and legislative empowerment are essential to foster further research.

Sustainable solid waste management is a critical component of the infrastructure essential for developing smart cities. Technological innovations, the Internet of Things in particular, are significant enablers for smart city applications, including solid waste management. The present analysis is dedicated to quantifying and assessing research progress in solid waste management via IoT applications, recognizing research dynamics as a crucial innovation metric. The objective is to offer invaluable insights to both practitioners and researchers, thereby guiding future research directions. The Scopus database was used to perform an in-depth investigation of scientific publications on IoT supporting solid waste management. VOSviewer software was employed to investigate knowledge networks and prominent topics. The study identified 325 documents, with India leading the field with 160 documents (49.2

This paper reports the effect of light intensity on the performance of PEC solar cells using CdSe thin films deposited via a combined electrodeposition (ED) and chemical bath deposition (CBD) technique. The ED method produced a thinner primary layer with excellent adhesion to FTO but insufficient photon absorption, whereas the subsequent CBD layer increased in thickness, enabling better photon absorption and greater photocurrent generation. The optical and structural properties of the films under consideration were calculated from the results of UV‒Vis spectroscopy, XRD, and SEM. J–V characterization at light intensities of 0.0025, 0.005, 0.010, and 0.020 W/cm2 indicated that increasing the light intensity increased the photocurrent and decreased the quantum yield efficiency. The dependence of the photocurrent on light intensity reflects a logarithmic increase whereby higher intensities generate many electron‒hole pairs, hence increasing the photocurrent. However, the quantum yield efficiency decreases logarithmically as the light intensity increases due to recombination losses. This inverse logarithmic relationship shows that the light conditions are optimized so that a balanced photocurrent and efficiency can be obtained to maximize the performance of solar cells. The parameters that could influence the optimization of PEC solar cells include the size of the particles and the deposition technique. Obviously, the conjoined CBD/ED method could produce smaller particles with higher efficiency. These results are part of the development of technologies for efficient and stable solar energy conversion.

The following study depicts the effect of light intensity on the performance of CdS thin-film photoelectrochemical cells. The thin films exhibit strong absorbance over the UV and visible regions, with an absorption edge located at approximately 510 nm, corresponding to the bulk CdS directly exhibiting a bandgap. The bandgap of approximately 2.46 eV obtained by the Tauc plot analysis is in agreement with known values and is very important for the optimization of the optoelectronic properties of the material. This calculation of d values is obtained from the XRD pattern. From the measurements, it was found that the crystallite size varied in the range of 25–30 nm. These SEM images show the surface morphology of the film, which confirmed its homogeneity with large agglomerates of CdS, in which nanosized particles were embedded. The n-type semiconducting nature of the films is thus confirmed by J–V measurements under illumination with different light intensities ( 2.5× 10^-3 , 5.0× 10^-3 , 10.0× 10^-3 , and 20.0× 10^-3 Wcm−2). The variation in key PEC performances, short-circuit current density (Jsc), open-circuit potential (Voc), fill factor (FF), and conversion efficiency (η), is dependent on light intensity. The results revealed that the logarithmic dependency of the light intensity on the photocurrent resulted in a good linear regression fit, with an R2 of approximately 0.97 and a relatively high R2. However, nonuniform light absorption, increased recombination rates, and thermal effects at high light intensities all result in decreased efficiencies. This finding argues in favor of optimum light intensity management for better PEC cell performance.

This study aims to explore the antimicrobial and photocatalytic efficiencies of pure and Ni-doped ZnO nanostructures produced via Laser-assisted Chemical Bath Synthesis (LACBS) to develop sustainable solutions for water treatment and pathogen control amid the global water crisis exacerbated by climate change and environmental pollution. Utilizing zinc acetate dihydrate and hexamethylenetetramine, the nanostructures were synthesized with Ni doping levels of 0.0%, 1.5%, 3.0%, and 4.5%, targeting their promising photocatalytic and antimicrobial properties to combat contaminants from pharmaceuticals, agriculture, and industries. Morphological analyses using Scanning Electron Microscopy showed a transition from hexagonal particles to nanoflowers, enhancing photocatalytic activity due to increased surface-to-volume ratio. X-ray Diffraction confirmed the hexagonal wurtzite structure, with variations in peak intensities indicating improved crystallinity with Ni doping. Energy Dispersive X-ray analysis verified the purity and successful incorporation of Ni. Photocatalytic assessments indicated up to 99.24% degradation of Methylene Orange dye under blue laser irradiation within 60minutes, correlating with Ni content. Antimicrobial tests demonstrated effective inhibition of pathogens such as Escherichia coli, Staphylococcus aureus, and additional strains like Candida albicans and Klebsiella pneumonia, with increasing zones of inhibition corresponding to higher Ni levels, extending up to 37mm. The results underscore the dual functionality of ZnO nanostructures for applications in sustainable water treatment and antimicrobial controls, highlighting the need for future studies to examine the impacts of further increased doping concentrations on the material properties and efficacy.

This work focuses on the interplay between redox couple activity and electrolyte concentration in terms of quantum cell efficiency and photocurrent in CdS thin-film photoelectrochemical solar cells. Optimization of the CdS thin-film electrodes was achieved through electrodeposition and chemical bath deposition, followed by controlled annealing. UV–visible electronic spectroscopy and Tauc measurements were used to determine that the energy gap of the CdS electrode was 2.4 eV. XRD confirmed the cubic structure of CdS, while SEM images revealed the agglomeration of CdS nanoparticles. The PEC performance with respect to different concentrations of NaOH/Na2S/S electrolyte, that is, 0.25, 0.5, 0.75, and 1 M, was studied; the results revealed that the activity of the redox couple improved the efficiency. In this context, the ionic strength and redox solution activity were calculated by the Debye–Hückel equation. Specifically, a clear correlation was clearly obtained in this study between the PEC efficiency and solution activity (R2 = 0.95 for the quantum cell efficiency and R2 = 0.93 for the photocurrent density), which is greater than that obtained for the concentration alone, for which R2 = 0.88 for the quantum cell efficiency and 0.83 for the photocurrent density. Consequently, the variation in ionic activity is one of the major parameters controlling the performance of PECs and, accordingly, solar energy conversion.

Access to clean water is crucial for human survival, yet global water pollution persists due to organic contaminants. Adsorption, using materials like montmorillonite clay, is a well-established method to purify water. However, the adsorption capacity diminishes over time as pollutants saturate the material. This study focuses on employing montmorillonite (MONT) to eliminate tetracycline (TC) from contaminated water, introducing a novel approach to address contaminant buildup on the adsorbent. Thermal combustion effectively decomposes adsorbed contaminants, regenerating and activating MONT for further adsorption without the adsorbed TC. Results show high efficiency, achieving complete TC adsorption in 40 minutes with only 0.1g of MONT in a 100 mL solution of 100 ppm TC. Characterization confirms MONT stability during use, activation, and reuse. This study highlights thermally stable adsorbents, like MONT, as environmentally safe, economically sensible, and sustainable for eliminating organic pollutants from water sources. The proposed technique supplements current water treatment methods, offering hope amid the global water contamination crisis by thermally decomposing and removing adsorbed TC. Kinetic isotherms experiments align with Langmuir adsorption, supporting a monolayer adsorption of TC on MONT surface. The pseudo-second-order model elucidates the adsorption mechanism, and Gibbs free energy and entropy values suggest a chemisorption predominance mechanism.

This study utilizes a novel laser-assisted chemical bath synthesis (LACBS) approach to dope zinc oxide (ZnO) nanostructures with aluminum (Al) and silver (Ag), examining enhancements in photocatalytic and antimicrobial capabilities. The configurations tested include undoped ZnO, singly-doped ZnO (0.05) and ZnO (0.05) , and co-doped ZnO:[Ag(0.025), (0.025) , Al (0.025) ]. X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses reveal shifts in lattice orientations and novel morphologies such as crumpled nano-flakes and interlocked flower-like formations. UV-visible - visible spectroscopy results show a reduction in optical band gaps from 3.39 eV in undoped ZnO to 2.89 eV in co-doped samples. Photocatalytic activity testing under UV light reveals that undoped ZnO reaches a 68 % degradation efficiency of methylene blue over 10 min, while co-doped ZnO exhibits a superior 78.93 % efficiency under blue laser illumination. Antimicrobial assays indicate that co-doped ZnO inhibits Escherichia coli and Klebsiella pneumonia growth with zones of inhibition up to 40 mm, significantly larger than those observed with singly-doped or undoped samples. The integration of Al and Ag significantly enhances the crystalline structure, reduces the optical band gap by up to 0.50 eV, and increases both photocatalytic and antimicrobial effectiveness, marking substantial progress in the functional applications of ZnO nanostructures.

This study investigates the relationships among redox couple activity, electrolyte concentration, and efficiency in CdSe thin-film photoelectrochemical solar cells. A CdSe photo-electrode was prepared using the electro-depositing technique to produce well-staged layering of CdSe, followed by chemical bath deposition to produce a layer with an acceptable thickness to absorb enough photons to create a suitable amount of photocurrent. The CdSe photo-electrochemical cell was tested under various concentrations of a NaOH/Na2S/S electrolyte solution. The results showed that the activity of the redox couple greatly affected the efficiencies of the solar cells. Correlation plots between ionic strength and PEC efficiency with the Debye–Hückel equation yielded an R² value of 0.96, while those between ionic strength and photocurrent density had an R² value of 0.92. The correlation between concentration and PEC efficiency was much weaker. This paper highlights how optimal ionic activity increases the performance of photoelectrochemical solar cells, which consequently improves the conversion efficiency of solar energy.

This research focused on the photodegradation of the insecticide imidacloprid (IM) via a ZnO@Ca-Alginate composite catalyst to address water contamination issues, particularly in agricultural areas such as Palestine. The composite was synthesized and characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), energy dispersive X-ray (EDX), thermogravimetric analysis (TGA), and Fourier transform infrared (FT-IR) spectroscopy, confirming the presence of ZnO. Photocatalytic experiments under simulated solar light revealed significant IM degradation, with a 50 % reduction in 40 minutes, an 80 % reduction in 2 hours, and up to 94 % in 3 hours. The degradation efficiency was influenced by the point of zero charge (pHzcp) and solution pH, with optimal performance under neutral to slightly basic conditions. UV-visible spectrophotometry, high-performance liquid chromatography (HPLC), and total organic carbon (TOC) analyses verified complete IM mineralization, yielding CO2, Cl-, and NO3- after 3 hours. The ZnO@Ca-Alginate composite demonstrated high reusability, highlighting its potential for treating pesticide-contaminated water. This study emphasizes the need for efficient pollutant removal technologies in regions where agricultural pollutants are prevalent.

Addressing the dual challenges of antimicrobial resistance and pharmaceutical contamination in wastewater is crucial for global health and environmental preservation. Predictions estimate up to 10 million annual deaths by 2050 due to antimicrobial resistance, underscoring the urgent need for innovative solutions. This study explores the potential of zinc oxide Sub-Microparticles (ZnO SMPs) doped with iron (Fe) to enhance the photocatalytic degradation of pharmaceutical compounds in water and improve antimicrobial efficacy. A green laser-assisted chemical bath synthesis method created ZnO SMPs with varying Fe dopant concentrations (1 %, 1.5 %, and 3 %). The synthesized Sub-Microparticles underwent rigorous structural analysis using X-ray diffractometry, SEM, EDX, FTIR, and UV-visible spectrophotometry techniques. Their photocatalytic performance was evaluated in the degradation of paracetamol under blue laser light, and their antimicrobial properties were assessed following CLSI guidelines. Structural analyses confirmed the hexagonal wurtzite structure of ZnO SMPs, with noticeable changes due to Fe doping, including a transition from sub-microrods to sub-microsheets and a redshift in the optical band gap. Photocatalytic tests revealed a significant enhancement in paracetamol degradation efficiency, increasing from 53.41 % with pure ZnO to 98.99 % with 3 % Fe-doped ZnO in 50 min. Antimicrobial assays demonstrated an increased inhibitory effect against pathogens, with Fe-doped ZnO outperforming control discs. This study substantiates the potential of Fe-doped ZnO SMPs in wastewater treatment and antimicrobial applications, showcasing significant improvements in photocatalytic degradation of pharmaceutical compounds and antimicrobial efficacy. The findings underscore the importance of continuing research in this domain for environmental and public health benefits.

A novel insoluble Ca-Alginate created from soluble Na-Alginate was used as a support substrate for ZnO nanoparticles producing ZnO@Ca-Alginate composite photocatalyst. Fourier Transform Infrared (FT-IR), Ultraviolet-Visible (UV-Vis), Thermogravimetric Analysis (TGA), Scanning Electron Microscopy (SEM), Energy-Dispersive X-ray Spectroscopy (EDX), and X-ray Diffraction (XRD) analysis techniques were used in the characterization of the prepared ZnO@Ca-Alginate. The ZnO@Ca-Alginate was tested for its potential use in the photodegradation of Methylene Blue (MB) from an aqueous solution under solar-simulated light. This composite photocatalyst efficiency in MB removal was compared with naked ZnO potential considering different conditions and parameters (e.g. pH, MB concentration, amount of photocatalyst, and irradiation time). The MB concentrations were identified using UV-vis spectrophotometric methods. While, high-performance liquid chromatography (HPLC), Total organic carbon (TOC) analysis, and other elemental analyses were used to confirm the MB complete mineralization. The MB photodegradation results were performed by using UV-vis analysis., the results showed that up to 95% of MB (40 mL, 40 ppm) was removed within 30 min of irradiation using either ZnO@Ca-Alginate or naked ZnO. The pH and the zero-charge point (Pzc) values play a main role in the adsorption and photodegradation results. The Pzc values for Ca-Alginate, ZnO, and Zn@Ca-Alginate were 6.5, 8.8, and 6.8 respectively. The prepared composite catalyst showed a maximum adsorption and photodegradation in a basic to slightly basic medium, the MB completely removed at pH of 7.7 within an hour of irradiation. The complete miniralzation of MB at the end of the photodegrdation process was confirmed. Here it is proved that the ZnO@Ca-Alginate photocatalyst can be recovered and reused without any significant decrease in its effectiveness.

This study investigates the effect of using SnO2 as a window layer in a heterojunction Mo/ZnTe/ZnSe/SnO2 thin film-solar cell, which, when compared to other absorber layer materials, has the potential to be used in solar photovoltaic applications due to its low cost, non-toxic nature, and ease of availability. The research has aimed to compare the impact of SnO2 with ZnO, which has been previously used as a window layer. Numerical modeling using the Solar Cell Capacitance Simulator (SCAPS-1D) has been conducted to analyze the effect of temperature and defects in the thin-film layers on the overall performance of the solar cell. Efficiency parameters such as short-circuit current density JSC, open-circuit voltage VOC, fill factor FF, and efficiency η, have been found to be influenced by temperature, and the effect of defects between the layers was analyzed. The optimal operating temperature for the solar cell with SnO2 as a window layer has been found to be 375 K, which has not required cooling to maintain cell efficiency, unlike the optimal operating temperature of 300 K for the solar cell with ZnO as a window layer. The simulation results have showed that using SnO2 as a window layer is advantageous due to the higher optimal operating temperature and the absence of the need for cooling to maintain cell efficiency. The study highlights the significance of quality control during fabrication in order to minimize defects and enhance the efficiency of the solar cell.

Antimicrobial resistance poses a significant threat to global health, amplified by factors such as water scarcity and suboptimal hygienic practices. Addressing AMR effectively necessitates a comprehensive strategy encompassing enhanced access to potable water, developing innovative antibiotics, and exploring alternative treatment modalities, such as harnessing solar photocatalysis with zinc oxide nanoparticles for water purification and antimicrobial applications. The Laser-Assisted Chemical Bath Synthesis (LACBS) technique facilitates the fabrication of pure ZnO nanostructures, providing a potentially efficacious solution for mitigating pathogen proliferation and managing wastewater. The photocatalytic degradation of MB and MO dyes was investigated using blue laser light at 445 nm, and degradation rates were determined accordingly. Ag-doped ZnO nanostructures were characterized through X-ray diffraction, field emission scanning electron microscopy, energy dispersive X-ray spectroscopy, and Fourier-transform infrared spectroscopy. The antimicrobial efficacy of LACBS-synthesized ZnO nanoparticles was assessed against C. albicans, S. aureus, B. subtilis, E. coli, and K. pneumoniae using the disc diffusion method, revealing 40 mm, 37 mm, 21 mm, 27 mm, and 45 mm inhibition zones at the highest concentration of doped-Ag (4.5%), respectively. These inhibition zones were measured in accordance with the guidelines established by the Clinical and Laboratory Standards Institute. X-ray diffraction patterns for ZnO, ZnOAg(1.5%), ZnO:Ag-(3%), and ZnO:Ag-(4.5%) samples revealed variations in intensity and crystallinity. Scanning electron microscopy exposed morphological disparities among the nanostructures, while energy-dispersive X-ray spectroscopy verified their elemental compositions. UV-Vis absorption analyses inspected the optical band gaps, and Fourier-transform infrared spectra identified the stretching mode of metal-oxygen bonds. Under blue laser irradiation, Ag-doped ZnO exhibited enhanced photocatalytic activity during the photocatalytic degradation. These nanoparticles, synthesized via the cost-effective and straightforward LACBS method, benefit from silver doping that augments their electron-trapping properties and photocatalytic activity, thereby enabling efficient dye degradation. Consequently, Ag-doped ZnO nanoparticles hold promise as a potent solution for counteracting drug-resistant microorganisms and as an effective disinfectant.

Pure and Ni-doped (1%, 2%, and 3%) nanostructures were synthesized using a novel laser-assisted chemical bath synthesis (LACBS) technique. For the first time, LACBS was used to create a doping solution utilizing a 7 W blue laser with a 444.4 nm wavelength and a continuous beam. The Ni-doping concentration was varied by changing the amount of Ni precursor added. All samples were analyzed using XRD, SEM, EDX, FTIR, UV–Vis, and photocatalysis tests for photodegradation under blue laser illumination. XRD was used to confirm that the tested ZnO had a hexagonal wurtzite structure. The crystallite size decreased as the Ni-doping concentration rose. EDX experiments were conducted to analyze the elemental characteristics of the pure and Ni-doped (1%, 2%, and 3%) nanostructures. The existence of nanoscale hexagonal structures was confirmed through SEM studies. The band gap values of the pure and Ni-doped ZnO nanostructures decreased as the doping concentration increased. FTIR studies were conducted to examine the functional groups of the pure and doped samples. The produced materials exhibited excellent photocatalytic performance toward the degradation of MB organic dye, an example of a pollutant found in wastewater.

Water, sanitation, and hygiene (WASH) services play a crucial role in promoting public and environmental health as well as social and economic development. At the global level, particularly in the developing world, WASH issues continue to present significant challenges. These challenges have been further intensified by factors such as the COVID-19 pandemic, escalating conflicts, climate change, water scarcity, and rising inequality. The scientific community has actively engaged in constructive discussions on these issues, as evidenced by the notable research findings. Therefore, the aim of this study was to comprehensively examine and evaluate global knowledge on WASH. To search for relevant publications, the Scopus database was utilized using specific terms associated with WASH. VOSviewer 1.6.18 software was employed to generate network visualization maps, which assessed collaborative patterns and research trends in the field of WASH. The research output of countries was adjusted considering their gross domestic product (GDP) and population size. The total number of WASH-related publications, including all types of documents, was 1805. By narrowing the search to articles and reviews, the overall global productivity yielded 1589 documents: 1367 (86.0%) original articles and 222 (14.0%) review articles. The USA had the highest number of WASH publications ( n = 668; 42.0%), followed by the UK ( n = 396; 24.9%), Switzerland ( n = 151; 9.5%), and Australia ( n = 141; 8.9%). Ethiopia emerged as the leading country in terms of GDP per capita and the number of publications, followed by Uganda, Malawi, India, and Bangladesh. The USA, the UK, and Switzerland exhibited the most extensive collaboration among countries. The main research areas encompassed the role of WASH in sustainable development, the impacts of inadequate access to WASH services on gender equality, children, infants, and the outbreak of COVID-19 and other diseases, as well as the significance of hygiene practices and community and school-based WASH interventions in reducing infections. This study provides a novel analysis of global WASH-related research and highlights the distribution of outcomes across nations. Continued and increased collaboration between developed and developing nations will facilitate the sharing of responsibility for WASH research outcomes and the implementation of effective policies.

This study used laser-assisted chemical bath synthesis (LACBS) as a simple, catalyst-free hydrothermal approach to synthesize pure and Al-doped ZnO nanostructures. Under the influence of a blue laser, the photocatalytic degradation of methylene blue has been studied (444.5 nm of wavelength and 8000 lx of light intensity). For the first time, LACBS produced numerous doping concentrations (2, 4, and 6

Abstract Ensuring access to clean and safe water is a critical aspect of human survival, yet water pollution caused by organic contaminants remains a significant global challenge. Adsorption, which involves using an adsorbent material to remove pollutants, is a well-established technique for purifying water from organic contaminants. However, the adsorption capacity of the material decreases over time as it becomes saturated with the adsorbed pollutants. In this study, the researchers used montmorillonite, a naturally occurring and readily available clay mineral, as an adsorbent material for the removal of tetracycline from water sources. The results demonstrate that montmorillonite is an efficient adsorbent, with complete adsorption of tetracycline achieved within 40 minutes of stirring using just 0.1g of montmorillonite with tetracycline (100 mL, 100 ppm). Furthermore, the study presents a novel approach to regenerate and activate used montmorillonite through thermal combustion, allowing for its reuse in further adsorption processes. The stability of the annealed montmorillonite was confirmed by characterization techniques such as TGA and FT-IR. The findings suggest that montmorillonite is a sustainable, low-cost, and effective adsorbent material for the removal of o from water sources and holds potential for removing other organic pollutants (such as pesticides, insecticides, herbicides, dyes, pharmaceuticals), presenting a valuable addition to existing water treatment methods.