Low-temperature synthesis, characterization and photocatalytic properties of lanthanum vanadate LaVO4

Energy transfer mechanism and optical properties of Eu3+, Dy3+ co-doped LaVO4 phosphors

The synthesis of aseries of orange-red Eu-doped LaVO4:0.05Dy3+ phosphors with a pH value of 9 by a hydrothermal method, varying the Eu3+ concentration. It was found that the optimal concentration of Eu3+ for enhanced luminescence in LaVO4:0.05Dy3+, xEu3+ is 0.07. A detailed analysis of the structure and morphology of the crystals, coupled with an in-depth examination of the photoluminescence(PL) behavior of the phosphor, led to the conclusion that energy transfer between Dy3+ and Eu3+ facilitates the luminescence. Moreover, low color temperature, high color rendering index(CRI), and orange-red LED devices were effectively fabricated utilizing LaVO4:0.05Dy3+, 0.07Eu3+ samples. The energy bands, density of states, and optical properties of the m-LaVO4 crystals were analyzed by first-principle counting of the crystals using density-functional theory. The results demonstrate that the co-doping of Eu3+ and Dy3+ can effectively reduce the forbidden band width of m-LaVO4.

Nanocellulose: A novel pathway to sustainable agriculture, environmental protection, and circular bioeconomy

Nanocellulose, obtained from natural cellulose, has attracted considerable interest for its distinctive properties and wide-ranging potential applications. Studies suggest that nanocellulose improves the thermal, mechanical, and barrier properties of conventional cellulose. This review investigates the production, properties, approach, and application of nanocellulose from various sources in agriculture. The main role play of cellulose-nanocomposite is discussed as a seed coating agent to improve seed dispersal, germination, protection against fungi and insects, plant growth promoter, adsorption of targeted pollutants, providing water and nutrient retention, and other advantages. As a nobility, we included all mechanical, chemical, and static culture approaches to the production procedure of nanocellulose and its application as a nanocarrier in soil, including the unique properties of nanocellulose, such as its high surface area, inherent hydrophilicity, and ease of surface modification. Here, methods such as melt compounding, solution casting, and in situ polymerization were evaluated to incorporate nanoparticles into cellulose materials and produce nanocellulose and cellulose-nanocomposites with improved strength, stability, water resistance, and reduced gas permeability. The commercialization faces challenges such as high production costs, scalability issues, and the need for more research on environmental impacts and plant interactions. Despite these hurdles, this field is promising, with ongoing advancements likely to yield new and improved agricultural materials. This review thoroughly examines the innovative application of nanocellulose in slow and controlled-release fertilizers and pesticides, to transform nutrient management, boost crop productivity, and minimize the environmental impact.

Precision Atomistic Structures of Actinium-/Radium-/Barium-Doped Lanthanide Nanoconstructs for Radiotherapeutic Applications

Lanthanide vanadate (LnVO4) nanoconstructs have generated considerable interest in radiotherapeutic applications as a medium for nanoscale-targeted drug delivery. For cancer treatment, LnVO4 nanoconstructs have shown promise in encapsulating and retaining radionuclides that emit alpha-particles. In this work, we examined the structure formation of LnVO4 nanoconstructs doped with actinium (Ac) and radium (Ra), both experimentally and using large-scale atomistic molecular dynamics simulations. LnVO4 nanoconstructs were synthesized via a precipitation method in aqueous media. The reaction conditions and elemental compositions were varied to control the structure, fluorescence properties, and size distribution of the LnVO4 nanoconstructs. LnVO4 nanoconstructs were characterized by X-ray diffraction, Raman spectroscopy, and fluorescence spectroscopy. Molecular dynamics simulations were performed to obtain a fundamental understanding of the structure-property relationship between radionuclides and LnVO4 nanoconstructs at the atomic length scale. Molecular dynamics simulations with well-established force field (FF) parameters show that Ra atoms tend to distribute across the nanoconstructs' surface in a broader coordination shell, while the Ac atoms are arranged inside a smaller coordination shell within the nanocluster. The Ba atoms prefer to self-assemble around the surface. These theoretical/simulation predictions of the atomistic structures and an understanding of the relationship between radionuclides and LnVO4 nanoconstructs at the atomic scale are important because they provide design principles for the future development of nanoconstructs for targeted radionuclide delivery.

Recent trends in the phytoremediation of radionuclide contamination of soil by cesium and strontium: Sources, mechanisms and methods: A comprehensive review

This comprehensive review examines recent trends in phytoremediation strategies to address soil radionuclide contamination by cesium (Cs) and strontium (Sr). Radionuclide contamination, resulting from natural processes and nuclear-related activities such as accidents and the operation of nuclear facilities, poses significant risks to the environment and human health. Cs and Sr, prominent radionuclides involved in nuclear accidents, exhibit chemical properties that contribute to their toxicity, including easy uptake, high solubility, and long half-lives. Phytoremediation is emerging as a promising and environmentally friendly approach to mitigate radionuclide contamination by exploiting the ability of plants to extract toxic elements from soil and water. This review focuses specifically on the removal of 90Sr and 137Cs, addressing their health risks and environmental implications. Understanding the mechanisms governing plant uptake of radionuclides is critical and is influenced by factors such as plant species, soil texture, and physicochemical properties. Phytoremediation not only addresses immediate contamination challenges but also provides long-term benefits for ecosystem restoration and sustainable development. By improving soil health, biodiversity, and ecosystem resilience, phytoremediation is in line with global sustainability goals and environmental protection initiatives. This review aims to provide insights into effective strategies for mitigating environmental hazards associated with radionuclide contamination and to highlight the importance of phytoremediation in environmental remediation efforts.

Design and application of metal organic frameworks for heavy metals adsorption in water: a review

The growing apprehension surrounding heavy metal pollution in both environmental and industrial contexts has spurred extensive research into adsorption materials aimed at efficient remediation. Among these materials, Metal-Organic Frameworks (MOFs) have risen as versatile and promising contenders due to their adjustable properties, expansive surface areas, and sustainable characteristics, compared to traditional options like activated carbon and zeolites. This exhaustive review delves into the synthesis techniques, structural diversity, and adsorption capabilities of MOFs for the effective removal of heavy metals. The article explores the evolution of MOF design and fabrication methods, highlighting pivotal parameters influencing their adsorption performance, such as pore size, surface area, and the presence of functional groups. In this perspective review, a thorough analysis of various MOFs is presented, emphasizing the crucial role of ligands and metal nodes in adapting MOF properties for heavy metal removal. Moreover, the review delves into recent advancements in MOF-based composites and hybrid materials, shedding light on their heightened adsorption capacities, recyclability, and potential for regeneration. Challenges for optimization, regeneration efficiency and minimizing costs for large-scale applications are discussed.

Recent advances in nano-fertilizers: synthesis, crop yield impact, and economic analysis

The escalating global demand for food production has predominantly relied on the extensive application of conventional fertilizers (CFs). However, the increased use of CFs has raised concerns regarding environmental risks, including soil and water contamination, especially within cereal-based cropping systems. In response, the agricultural sector has witnessed the emergence of healthier alternatives by utilizing nanotechnology and nano-fertilizers (NFs). These innovative NFs harness the remarkable properties of nanoparticles, ranging in size from 1 to 100 nm, such as nanoclays and zeolites, to enhance nutrient utilization efficiency. Unlike their conventional counterparts, NFs offer many advantages, including variable solubility, consistent and effective performance, controlled release mechanisms, enhanced targeted activity, reduced eco-toxicity, and straightforward and safe delivery and disposal methods. By facilitating rapid and complete plant absorption, NFs effectively conserve nutrients that would otherwise go to waste, mitigating potential environmental harm. Moreover, their superior formulations enable more efficient promotion of sustainable crop growth and production than conventional fertilizers. This review comprehensively examines the global utilization of NFs, emphasizing their immense potential in maintaining environmentally friendly crop output while ensuring agricultural sustainability.

Design of Bismuth Tungstate Bi2WO6 Photocatalyst for Enhanced and Environmentally Friendly Organic Pollutant Degradation

In this study, a chemical precipitation approach was adopted to produce a photocatalyst based on bismuth tungstate Bi2WO6 for enhanced and environmentally friendly organic pollutant degradation. Various tools such as X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), optical spectroscopy and X-ray photoelectron spectroscopy, were employed to assess the structural and morphological properties. Hence, the XRD profiles showed a well crystallized Bi2WO6 orthorhombic phase. The photocatalytic performance of the resulting photocatalyst was assessed by the decomposition of Rhodamine B (RhB) and methyl orange (MO) with a decomposition efficiency of 97 and 92%, along with the highest chemical oxygen demand of 82 and 79% during 120 min of illumination, respectively. The principal novelty of the present work is to focus on the changes in the crystalline structure, the morphology, and the optical and the photoelectrochemical characteristics of the Bi2WO6, by tuning the annealing temperature of the designed photocatalyst. Such physicochemical property changes in the as-prepared photocatalyst will affect in turn its photocatalytic activity toward the organic pollutant decomposition. The photocatalytic mechanism was elaborated based on electrochemical impedance spectroscopy, photocurrent analysis, photoluminescence spectroscopy, and radical trapping measurements. The overall data indicate that the superoxide O2•- and holes h+ are the principal species responsible for the pollutant photodegradation.

Nanocellulose: Structure, modification, biodegradation and applications in agriculture as slow/controlled release fertilizer, superabsorbent, and crop protection: A review

This review investigates the potential of nanocellulose in agriculture, encompassing its structure, synthesis, modification, and applications. Our investigation of the characteristics of nanocellulose includes a comprehensive classification of its structure. Various mechanical, chemical and enzymatic synthesis techniques are evaluated, each offering distinct possibilities. The central role of surface functionalization is thoroughly examined. In particular, we are evaluating the conventional production of nanocellulose, thus contributing to the novelty. This review is a pioneering effort to comprehensively explore the use of nanocellulose in slow and controlled release fertilizers, revolutionizing nutrient management and improving crop productivity with reduced environmental impact. Additionally, our work uniquely integrates diverse applications of nanocellulose in agriculture, ranging from slow-release fertilizers, superabsorbent cellulose hydrogels for drought stress mitigation, and long-lasting crop protection via nanocellulose-based seed coatings. The study ends by identifying challenges and unexplored opportunities in the use of nanocellulose in agriculture. This review makes an innovative contribution by being the first comprehensive study to examine the multiple applications of nanocellulose in agriculture, including slow-release and controlled-release fertilizers.

Superabsorbent hydrogels based on natural polysaccharides: Classification, synthesis, physicochemical properties, and agronomic efficacy under abiotic stress conditions: A review

Superabsorbent polymers (SAPs) are a class of polymers that have attracted tremendous interest due to their multifunctional properties and wide range of applications. The importance of this class of polymers is highlighted by the large number of publications, including articles and patents, dealing with the use of SAPs for various applications. Within this framework, this review provides an overview of SAPs and highlights various key aspects, such as their history, classification, and preparation methods, including those related to chemically or physically cross-linked networks, as well as key factors affecting their performance in terms of water absorption and storage. This review also examines the potential use of polysaccharides-based SAPs in agriculture as soil conditioners or slow-release fertilizers. The basic aspects of SAPs, and methods of chemical modification of polysaccharides are presented and guidelines for the preparation of hydrogels are given. The water retention and swelling mechanisms are discussed in light of some mathematical empirical models. The nutrient slow-release kinetics of nutrient-rich SAPs are also examined on the basic of commonly used mathematical models. Some examples illustrating the advantages of using SAPs in agriculture as soil conditioners and agrochemical carriers to improve crop growth and productivity are presented and discussed. This review also attempts to provide an overview of the role of SAPs in mitigating the adverse effects of various abiotic stresses, such as heavy metals, salinity, and drought, and outlines future trends and prospects.