Thin Films (FTO/BaTiO3/AgNPs) for Enhanced Piezo-Photocatalytic Degradation of Methylene Blue and Ciprofloxacin in Wastewater

Nanotechnology in action: silver nanoparticles for improved eco-friendly remediation

Nanotechnology is an exciting area with great potential for use in biotechnology due to the far-reaching effects of nanoscale materials and their size-dependent characteristics. Silver and other metal nanoparticles have attracted a lot of attention lately because of the exceptional optical, electrical, and antimicrobial characteristics they possess. Silver nanoparticles (AgNPs) stand out due to their cost-effectiveness and abundant presence in the earth's crust, making them a compelling subject for further exploration. The vital efficacy of silver nanoparticles in addressing environmental concerns is emphasized in this thorough overview that dives into their significance in environmental remediation. Leveraging the distinctive properties of AgNPs, such as their antibacterial and catalytic characteristics, innovative solutions for efficient treatment of pollutants are being developed. The review critically examines the transformative potential of silver nanoparticles, exploring their various applications and promising achievements in enhancing environmental remediation techniques. As environmental defenders, this study advocates for intensified investigation and application of silver nanoparticles. Furthermore, this review aims to assist future investigators in developing more cost-effective and efficient innovations involving AgNPs carrying nanoprobes. These nanoprobes have the potential to detect numerous groups of contaminants simultaneously, with a low limit of detection (LOD) and reliable reproducibility. The goal is to utilize these innovations for environmental remediation purposes.

Bioinspired copper oxide nanocomposites: harnessing plant extracts for enhanced photocatalytic performance

This study focuses on developing copper oxide-based nanocomposites using plant extracts for photocatalytic applications. Curcuma amada leaf and Alysicarpus vaginalis leaf extracts were utilized alongside recycled copper precursors to synthesize photocatalysts via a green synthesis approach. Structural characterization through X-ray diffraction confirmed the formation of monoclinic CuO with reduced crystallite sizes due to plant extract incorporation. Fourier-transform infrared spectroscopy identified additional functional groups from the plant extracts, enhancing the material's properties. UV-Vis spectroscopy demonstrated increased light absorption and narrowed bandgaps in the nanocomposites, crucial for efficient photocatalysis under visible light. Morphological studies using FESEM revealed unique leaf-like structures in nanocomposites, indicative of the plant extract's influence on morphology. Photocatalytic degradation of methylene blue, rhodamine B, Congo red, and reactive blue 171 dyes showed enhanced performance of plant extract-modified CuO compared to without plant extract mediated CuO, attributed to improved charge carrier separation and extended lifetime. The effects of pH, catalyst dosage, and dye concentration on degradation efficiency were systematically investigated, highlighting optimal conditions for each dye type. Radical scavenger studies confirmed the roles of holes and hydroxyl radicals in the degradation process. Kinetic analysis revealed pseudo-second-order kinetics for dye degradation, underscoring the effectiveness of the nanocomposites. Overall, this research provides insights into sustainable photocatalytic materials using plant extracts and recycled copper, showcasing their potential for environmental remediation applications.

Recent Advances in Functional Hydrogels for Treating Dental Hard Tissue and Endodontic Diseases

Oral health is the basis of human health, and almost everyone has been affected by oral diseases. Among them, endodontic disease is one of the most common oral diseases. Limited by the characteristics of oral biomaterials, clinical methods for endodontic disease treatment still face large challenges in terms of reliability and stability. The hydrogel is a kind of good biomaterial with an adjustable 3D network structure, excellent mechanical properties, and biocompatibility and is widely used in the basic and clinical research of endodontic disease. This Review discusses the recent advances in functional hydrogels for dental hard tissue and endodontic disease treatment. The emphasis is on the working principles and therapeutic effects of treating different diseases with functional hydrogels. Finally, the challenges and opportunities of hydrogels in oral clinical applications are discussed and proposed. Some viewpoints about the possible development direction of functional hydrogels for oral health in the future are also put forward. Through systematic analysis and conclusion of the recent advances in functional hydrogels for dental hard tissue and endodontic disease treatment, this Review may provide significant guidance and inspiration for oral disease and health in the future.

Organic pollutant degradation for micro-molecule product emission over SiO2 layers-coated g-C3N4 photocatalysts

In this study, a SiO2 layer-coated g-C3N4 catalyst was prepared by a sol-gel method to overcome the poor adsorption ability and high recombination rate of charge carriers of pristine g-C3N4. SEM and TEM images indicated that SiO2 nanoparticles were coated on the surface of g-C3N4 nanoparticles with a layered structure and the layers were tightly contacted with g-C3N4. XRD patterns, FTIR spectra, UV-vis spectra and XPS spectra revealed that the structure of g-C3N4 was not destroyed and its photoelectric catalytic properties were not suppressed by the coating of SiO2 layers. Adsorption experiments revealed that the SiO2 layers improved the adsorption performance of g-C3N4 and their ratios were adjusted. The molecular weights of the final products of the degradation of RhB and antibiotics were at the micro-molecule level while the amount of g-C3N4 reached 1.2% of the mass fraction, which were more suitable for pollutant degradation compared with those of g-C3N4 due to its poor adsorption ability. The reason for this was likely that the SiO2 layers were not only beneficial for the adsorption of pollutants and intermediate products but also for prolonging the life time of the separated electrons and holes. Finally, active trapping experiments confirmed that both the holes and superoxide radicals were the main factors in the degradation of RhB and antibiotics, with the superoxides being the most active species.

A comprehensive review on the application of semiconducting materials in the degradation of effluents and water splitting

In this comprehensive review article, we delve into the critical intersection of environmental science and materials science. The introduction sets the stage by emphasizing the global water shortage crisis and the dire consequences of untreated effluents on ecosystems and human health. As we progress into the second section, we embark on an intricate exploration of piezoelectric and photocatalytic principles, illuminating their significance in wastewater treatment and sustainable energy production. The heart of our review is dedicated to a detailed analysis of the detrimental impacts of effluents on human health, underscoring the urgency of effective treatment methods. We dissected three key materials in the realm of piezo-photocatalysis: ZnO-based materials, BaTiO3-based materials, and bismuth-doped materials. Each material is scrutinized for its unique properties and applications in the removal of pollutants from wastewater, offering a comprehensive understanding of their potential to address this critical issue. Furthermore, our exploration extends to the realm of hydrogen production, where we discuss various types of hydrogen and the role of piezo-photocatalysis in generating clean and sustainable hydrogen. By illuminating the synergistic potential of these advanced materials and technologies, we pave the way for innovative solutions to the pressing challenges of water pollution and renewable energy production. This review article not only serves as a valuable resource for researchers and scholars in the fields of material science and environmental engineering but also underscores the pivotal role of interdisciplinary approaches in addressing complex global issues.

Oxygen Vacancies and Surface Wettability: Key Factors in Activating and Enhancing the Solar Photocatalytic Activity of ZnO Tetrapods

This paper reports on the high photocatalytic activity of ZnO tetrapods (ZnO-Ts) using visible/solar light and hydrodynamic water flow. It was shown that surface oxygen defects are a key factor in the photocatalytic activity of the ZnO-Ts. The ability to control the surface wettability of the ZnO-Ts and the associated concentration of surface defects was demonstrated. It was demonstrated that the photocatalytic activity during the MB decomposition process under direct and simulated sunlight is essentially identical. This presents excellent prospects for utilizing the material in solar photocatalysis.

Sodium Alginate-CuS Nanostructures Synthesized at the Gel-Liquid Interface: An Efficient Photocatalyst for Redox Reaction and Water Remediation

The use of visible light to propel chemical reactions is an exciting area of study that is crucial in the current socioeconomic environment. However, various photocatalysts have been developed to harness visible light, which consume high energy during synthesis. Thus, synthesizing photocatalysts at gel-liquid interfaces in ambient conditions is of scientific importance. Herein, we report an environmentally benign sodium alginate gel being used as a biopolymer template to synthesize copper sulfide (CuS) nanostructures at the gel-liquid interface. The driving force for the synthesis of CuS nanostructures is varied by changing the pH of the reaction medium (i.e., pH 7.4, 10, and 13) to tailor the morphology of CuS nanostructures. The CuS nanoflakes obtained at pH 7.4 transform into nanocubes when the pH is raised to 10, and the nanostructures deform at the pH of 13. Fourier transform infrared spectroscopy (FTIR) confirms all the characteristic stretching of sodium alginate, whereas the CuS nanostructures are crystallized in a hexagonal crystal system, as revealed by the powder X-ray diffraction analysis. The high-resolution X-ray photoelectron spectroscopy (XPS) spectra show the +2 and -2 oxidation states of copper (Cu) and sulfur (S) ions, respectively. The CuS nanoflakes physisorbed a higher concentration of greenhouse CO₂ gas. Owing to a lower band gap of CuS nanoflakes synthesized at a pH of 7.4, compared to other CuS nanostructures prepared at pH 10 and 13, CuS photocatalytically degrades 95% of crystal violet and 98% of methylene blue aqueous dye solutions in 60 and 90 min, respectively, under blue light illumination. Additionally, sodium alginate-copper sulfide (SA-CuS) nanostructures synthesized at a pH of 7.4 demonstrate excellent performance in photoredox reactions to convert ferricyanide to ferrocyanide. The current research opens the door to developing new photocatalytic pathways for a wide range of photochemical reactions involving nanoparticle-impregnated alginate composites prepared on gel interfaces.

Silver Nanoparticles for Waste Water Management

Rapidly increasing industrialisation has human needs, but the consequences have added to the environmental harm. The pollution caused by several industries, including the dye industries, generates a large volume of wastewater containing dyes and hazardous chemicals that drains industrial effluents. The growing demand for readily available water, as well as the problem of polluted organic waste in reservoirs and streams, is a critical challenge for proper and sustainable development. Remediation has resulted in the need for an appropriate alternative to clear up the implications. Nanotechnology is an efficient and effective path to improve wastewater treatment/remediation. The effective surface properties and chemical activity of nanoparticles give them a better chance to remove or degrade the dye material from wastewater treatment. AgNPs (silver nanoparticles) are an efficient nanoparticle for the treatment of dye effluent that have been explored in many studies. The antimicrobial activity of AgNPs against several pathogens is well-recognised in the health and agriculture sectors. This review article summarises the applications of nanosilver-based particles in the dye removal/degradation process, effective water management strategies, and the field of agriculture.

Magnetically retrievable Fe3O4@SiO2@ZnO piezo-photocatalyst: Synthesis and multiple catalytic properties

The piezo-/photocatalytic effects of ZnO have been in the limelight because of their great potential in environmental remediation and energy conversion. However, the poor recyclability of the suspended catalysts can cause inevitable secondary pollution, which is one of the major issues that limit the practical application of these materials. To address this problem, a magnetically retrievable Fe₃O₄@SiO₂@ZnO nanocomposite was designed and successfully synthesized by multi-step reactions. The ZnO nanorods were vertically grown on the surface of the magnetic Fe₃O₄@SiO₂ microspheres, while SiO₂ served as an insulator to protect the inner core and to inhibit charge transfer across the core/shell interface. The Fe₃O₄@SiO₂@ZnO nanocomposite can be easily collected and separated by using a magnetic field. Along with the good recyclability, the material also exhibited high efficiencies in piezocatalytic, photocatalytic and piezo-photocatalytic dye degradation processes. The rate constant of piezo-photocatalysis reached 95.9 × 10^-3 min^-1, which was 2.2 and 6.1 times that of the individual piezocatalysis and photocatalysis, respectively. The present result confirmed the existence of a synergetic effect between piezo- and photocatalytic processes. Hereby, we demonstrated that incorporation of a magnetic carrier is a feasible strategy to achieve retrievable and highly efficient piezo-/photocatalyst.