Search Results (163)

The extensive use of clothianidin pesticide poses significant risks to non-target organisms and water resources. In this study, NiO-GO is reported as an effective photocatalyst for the degradation of clothianidin in aqueous medium. Nickel oxide (NiO) nanoparticles were synthesized by a green method using Pisum sativum (pea) peel extract, which serves as a natural reducing and stabilizing agent, and subsequently integrated with graphene oxide (GO) through ultrasonication to form a NiO-GO composite in a 1:1 ratio. The materials were characterized by various techniques. Photocatalytic degradation of clothianidin under natural sunlight was systematically investigated, assessing the effects of pH, catalyst dosage, initial pollutant concentration, and agitation speed. The NiO-GO composite exhibited superior photocatalytic performance (96% degradation at pH 3 within 60 min) compared to pristine NiO and GO, with a rate constant 4.4 and 3.3 times higher, respectively. The as-prepared NiO-GO photocatalyst exhibited nearly consistent degradation efficiency over two successive cycles, demonstrating its excellent structural stability and reusability. The enhanced performance is attributed to improved charge separation afforded by GO support. This low-cost, green, and efficient NiO-GO photocatalyst demonstrates promising potential for sustainable pesticide remediation in aqueous environments. Full article

For five decades, photocatalysis has promised clean hydrogen from solar energy, yet a persistent “efficiency ceiling”, linked to fundamental challenges including the trade-off between light absorption and redox potential in single-component materials, has hindered its practical application. This review illuminates three key paradigm shifts overcoming this challenge. First, we examine Z-scheme and S-scheme heterojunctions, which resolve the bandgap dilemma by spatially separating redox sites to achieve both broad light absorption and strong redox power. Second, we discuss replacing the sluggish oxygen evolution reaction (OER) with value-added organic oxidations. This strategy bypasses kinetic bottlenecks and improves economic viability by co-producing valuable chemicals from feedstocks like biomass and plastic waste. Third, we explore manipulating the reaction environment, where synergistic photothermal effects and concentrated sunlight can dramatically enhance kinetics and unlock markedly enhanced solar-to-hydrogen (STH) efficiencies. Collectively, these strategies chart a clear course to overcome historical limitations and realize photocatalysis as an impactful technology for a sustainable energy future. Full article

This paper reports a novel effort to estimate and evaluate the coefficients of Hg transfer across the water/air interface in lakes such as Cane Creek Lake (CCL, Cookeville, TN, USA). This was accomplished by calculating the coefficients (k_w) using the Two-Thin Film (TTF) Model for Hg transfer together with the field-measured data of Hg emission flux (F), dissolved gaseous mercury concentration (DGM), air Hg concentration (C_a), and water temperature for Henry’s coefficient (K_H) obtained from a separate field study at the CCL. The daily mean k_w values range from 0.045 to 0.21 m h⁻¹, with the min. at 0.0025–0.14 and the max. at 0.079–0.41 m h⁻¹, generally higher for the summer, and from 0.0092 to 0.15, with the min. at 0.0032–0.033 and the max. at 0.017–0.31 m h⁻¹, generally lower for the fall and winter, exhibiting an apparent seasonal trend. The highest k_w values occur in August (mean: 0.21, max.: 0.41 m h⁻¹). Our k_w results add to and enrich the aquatic interfacial Hg transfer coefficient database and provide an alternative avenue to evaluate and select the coefficients for the TTF Model’s application. The k_w results are of value in gaining insights into the Hg transfer actually occurring across the water/air interface under environmental influences (e.g., wind/wave, solar radiation). Our k_w results do not show a clear, consistent correlation of k_w with wind/wave effect, nor sunlight effect, in spite of some correlations in sporadic cases. Generally, the k_w values do not exbibit the trends prescribed by the model sensitivity study. The comparisons of our k_w results with those obtained using wind-based transfer models (the Liss/Merlivat Model, the Wanninkhof Model, and the modified linear model) show that they depart from each other. The findings of this study indicate that the TTF Model has limitations and weaknesses. One major assumption of the TTF Model is the equilibrium of the Hg distribution between the air and water films across the water/air interface. The predominant oversaturation of DGM shown by our DGM data evidently challenges this assumption. This study suggests that aquatic interfacial Hg transfer is considerably more complicated, involving a group of factors, more than just wind and wave. Full article

Micro- and nanoplastic (MNP) particles are constantly formed through plastic fragmentation by sunlight, friction, or oxidation. MNPs potentialize health risks when entering the human body by ingestion, infusion, inhalation, and skin absorption. Still, the translocation among intracellular compartments must also be considered because MNPs can reach the circulatory system and be found in virtually all body fluids, tissues, and organs, potentially causing significant health impacts. The ability of MNPs to interact with macromolecules and cause damage to intracellular structures results in several physiopathological conditions, such as inflammation, oxidative imbalance, apoptosis, and carcinogenesis. One major challenge in MNP research is the development of reliable detection and quantification methods and effective sample separation processes. Although there is evidence directly linking MNPs to heart disease, the same cannot be said for diseases such as cancer, respiratory conditions, and reproductive system disorders. Therefore, the impact of MNPs on human health was examined, and a careful evaluation of their effects was carried out. We reviewed the extensive scientific literature from the past years, focusing on exposure, aging, interactions, and effects on entering MNPs into human metabolism and the physiological systems, which makes these particles particularly hazardous. Full article

The importance of temperature for the biology and ecology of reptiles is well known. In temperate regions where temperatures fluctuate on a daily and seasonal basis, reptiles must respond appropriately to maintain body temperatures that enable activity. In this study, we describe temporal changes in the thermal environment from January to December in Montenegro and the impact on two species of reptile, Hermann’s tortoise, Testudo hermanni, and the large, legless lizard Pseudopus apodus. These reptiles differ in morphology and diet and have a long phylogenetic separation but experience the same thermal environment. To give insight into any impact of these factors on their thermal ecology we calculated monthly thermoregulatory efficiency indexes derived from field body temperatures, set point temperatures—defined as the preferred body temperatures, and temperatures of null models. The results indicated that both species exhibited high thermoregulatory efficiency, with T. hermanni showing the highest levels across the active year and also maintaining higher body temperatures than P. apodus potentially reflecting the dietary and lifestyle differences. During the hottest months, body temperatures of T. hermanni frequently exceeded the set point range but were not exceeded by P. apodus at any time. Microhabitat patches of closely situated sunlight and shaded areas were the most frequently selected patches in both species, with T. hermanni spending greater amounts of time in shaded patches compared to P. apodus. The efficiency indexes, together with data on microhabitat selection, indicated both species moved non-randomly through the environment, selecting appropriate habitat patches and maintaining body temperatures close to the set point range whilst avoiding the dangerously high body temperatures that occur during the hotter months. During the winter months from November to February, the second and third quartiles of the model temperatures fell below the set point range temperatures of both species. This corresponded with their dormant period. In general, the results emphasise the importance of habitat diversity and integrity in reptile ecology and for their conservation. Full article

A novel composite material comprising titanium dioxide and layered double hydroxides (TiO₂/LDHs) was innovatively proposed and prepared using the co-precipitation method to overcome the shortcomings of titanium dioxide, such as low efficiency in separating electron–hole pairs induced by light and a low utilization rate of visible light. This material was used to study the visible-light-driven photocatalytic degradation of methylene blue. The experimental results show that by constructing efficient heterojunction structures through the alignment of interface band energies and regulating the interface charge transfer pathways, the recombination rate of photogenerated electron–hole pairs is significantly reduced, and the photocatalytic activity is greatly enhanced. Among the tested samples, the TiO₂/LDHs composite material with an aluminum-to-titanium molar ratio of 1:1 (AT11) demonstrated the best photocatalytic performance. Within 70 min of simulated sunlight exposure, the degradation rate of methylene blue reached 98.2%, and the optimal concentration of the catalyst was 1 g/L. The photocatalytic process follows a first-order kinetic model. After four cycles of use, the degradation efficiency of methylene blue by the AT11 composite material was 78.93%, demonstrating good stability. The free radical capture experiments indicated that the main active substances for the photocatalytic degradation of methylene blue were h⁺ and ·OH. The constructed TiO₂/LDHs heterostructure system significantly enhanced the photocatalytic performance of TiO₂ materials, which was conducive to the efficient utilization of solar energy. Full article

Pyrolysis of oily sludge (OS) faces two significant challenges, dehydration in emulsion and coke formation, which cause extra energy consumption. Targeting energy saving, this paper first reported on solar photothermal dehydration and confined catalytic pyrolysis of OS using a single material. A wood sponge loaded with carbon dots (CM-CDs) can generate heat by absorbing solar energy and promote rapid phase separation and water transport via capillary action of oil–water emulsion in OS under sunlight. Almost all free water in OS with varied content can be removed after 3 h. Hydrocarbons entered the internal space of CM-CDs instead of contacting with soil minerals, contributed to the subsequent confined catalytic pyrolysis, led to a reduction in Ea (35.61 kJ/mol), inhibited coking and caking, and yielded higher oil recovery efficiency. In addition, CDs can form hotspots to enhance pyrolytic behaviors in local regions. When the ratio of OS to CM-CDs reached 10:0.6, the recovery rate of the oil fraction through combined pyrolysis was as high as 89%, which was 17% higher than that of OS pyrolysis alone. This discovery provides a new way to solve the bottleneck problems of OS pyrolysis in the industry. Full article

Persistent reactive azo dyes released from textile finishing are a serious threat to water systems, but effective methods using sunlight to break them down are still limited. Everzol Yellow 3RS (EY-3RS) is particularly recalcitrant: past studies have relied almost exclusively on physical adsorption onto natural or modified clays and zeolites, and no photocatalytic pathway employing engineered nanomaterials has been documented to date. This study reports the synthesis, characterization, and performance of a visible-active ternary nanocomposite, Cu₄O₃/ZrO₂/TiO₂, prepared hydrothermally alongside its binary (Cu₄O₃/ZrO₂) and rutile TiO₂ counterparts. XRD, FT-IR, SEM-EDX, UV-Vis, and PL analyses confirm a heterostructured architecture with a narrowed optical bandgap of 2.91 eV, efficient charge separation, and a mesoporous nanosphere-in-matrix morphology. Photocatalytic tests conducted under midsummer sunlight reveal that the ternary catalyst removes 91.41% of 40 ppm EY-3RS within 100 min, markedly surpassing the binary catalyst (86.65%) and TiO₂ (81.48%). Activity trends persist across a wide range of operational variables, including dye concentrations (20–100 ppm), catalyst dosages (10–40 mg), pH levels (3–11), and irradiation times (up to 100 min). The material retains ≈ 93% of its initial efficiency after four consecutive cycles, evidencing good reusability. This work introduces the first nanophotocatalytic strategy for EY-3RS degradation and underscores the promise of multi-oxide heterojunctions for solar-driven remediation of colored effluents. Full article

The vast majority of photocatalysts find it difficult to consistently and stably exhibit high performance due to the variability of sunlight intensity within a day, as well as the high energy consumption of artificial light sources. In this study, mechanoluminescent Sr₂MgSi₂O₇:Eu,Dy phosphors is combined with NiS@g-C₃N₄ composite to construct a ternary heterogeneous photocatalytic system, denoted as NCS. In addition to the enhanced separation efficiency of photogenerated charge carriers by the formation of a heterojunction, the introduction of Sr₂MgSi₂O₇:Eu,Dy provides an ultra-driving force for the photocatalytic reactions owing to its mechanoluminescence-induced excitation. Results show that the degradation rate of RhB increased significantly in comparison with pristine g-C₃N₄ and NiS@g-C₃N₄, indicating the obvious advantages of the ternary system for charge separation and migration. Moreover, the additional photocatalytic activity of NCS under ultrasound stimulation makes it a promising all-weather photocatalyst even in dark environments. This novel strategy opens up new horizons for the synergistic combination of light-driven and ultrasound-driven heterogeneous photocatalytic systems, and it also has important reference significance for the design and application of high-performance photocatalysts. Full article

Ag/AgCl-decorated layered lanthanum oxide (La₂O₃) and niobium pentoxide (Nb₂O₅) plasmonic photocatalysts are fabricated through an ionic liquid-mediated co-precipitation method. Scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), powder X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), diffuse reflectance spectroscopy (DRS), and photoluminescence (PL) techniques were used to illustrate the physicochemical properties of the materials. The photoactivity was evaluated for the degradation of Acid Blue 92 (AB92) azo dye, a typical organic contaminant from the textile industry, and U251 cancer cell inactivation. According to the results, Nb₂O₅–Ag/AgCl was able to remove >99% of AB92 solution in 35 min with the rate constant of 0.12 min⁻¹, 2.4 times higher than that of La₂O₃–Ag/AgCl. A pH of 3 and a catalyst dosage of 0.02 g were determined as the optimized factors to reach the highest degradation efficiency under solar energy at noon, which was opted to have the highest sunlight intensity over the reactor. Also, 0.02 mg/mL of Nb₂O₅–Ag/AgCl was determined to be of great potential to reduce cancer cell viability by more than 50%, revealed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and mitochondrial membrane potential (MMP) examinations. The mechanism of degradation was also discussed, considering the key role of Ag⁰ nanoparticles in inducing a plasmonic effect and improving the charge separation. This work provides helpful insights to opt for an efficient rare metal oxide with good biocompatibility as support for the plasmonic photocatalysts with the goal of environmental purification under sunlight. Full article

The growing presence of hazardous organic pollutants in wastewater poses severe environmental and health risks, necessitating sustainable and efficient treatment solutions. Traditional remediation methods have limitations, highlighting the need for innovative approaches. A green synthesis method was developed to produce TiO₂-CeO₂ nanocomposites using Cleistocalyx operculatus leaf extract. The photocatalytic efficiency of the synthesized nanocomposites was evaluated under simulated sunlight by degrading Methylene Blue (MB) dye. Various compositions were tested to determine the optimal performance. The 0.1% TiO₂-CeO₂ nanocomposite achieved the highest degradation efficiency (95.06% in 150 min) with a reaction rate constant (k) of 18.5 × 10⁻² min⁻¹, outperforming commercial TiO₂ (P25, 74.85%, k ≈ 3.7 × 10⁻² min⁻¹). Additionally, the material maintained excellent stability over eight consecutive cycles with only a slight decrease in efficiency from 95.85% to 93.28%. The enhanced photocatalytic activity is attributed to the synergistic effects of CeO₂ incorporation, which enhances charge separation, extends visible light absorption, and promotes reactive oxygen species (ROS) generation. These findings highlight the potential of green-synthesized TiO₂-CeO₂ nanocomposites as a cost-effective and sustainable solution for wastewater treatment. Full article

Photocatalytic hydrogen (H₂) production offers a promising solution to energy shortages and environmental challenges by converting solar energy into chemical energy. Hydrogen, as a versatile energy carrier, can be generated through photocatalysis under sunlight or via electrolysis powered by solar or wind energy. However, the advancement of photocatalysis is hindered by the limited availability of effective visible light-responsive semiconductors and the challenges of charge separation and transport. To address these issues, researchers are focusing on the development of novel nanostructured semiconductors and composite materials that can enhance photocatalytic performance. In this paper, we provide an overview of the advanced photocatalytic materials prepared so far that can be activated by sunlight, and their efficiency in H₂ production. One of the key strategies in this research area concerns improving the separation and transfer of electron–hole pairs generated by light, which can significantly boost H₂ production. Advanced hybrid materials, such as organic–inorganic hybrid composites consisting of a combination of polymers with metal oxide photocatalysts, and the creation of heterojunctions, are seen as effective methods to improve charge separation and interfacial interactions. The development of Schottky heterojunctions, Z-type heterojunctions, p–n heterojunctions from nanostructures, and the incorporation of nonmetallic atoms have proven to reduce photocorrosion and enhance photocatalytic efficiency. Despite these advancements, designing efficient semiconductor-based heterojunctions at the atomic scale remains a significant challenge for the realization of large-scale photocatalytic H₂ production. In this review, state-of-the-art advancements in photocatalytic hydrogen production are presented and discussed in detail, with a focus on photocatalytic nanostructures, heterojunctions and hybrid composites. Full article

Food spoilage caused by microbial contamination remains a global challenge, driving demand for sustainable antibacterial packaging. Conventional photocatalytic materials suffer from limited spectral response, rapid charge recombination, and insufficient reactive oxygen species (ROS) generation under visible light. Here, a Z-scheme heterojunction was constructed by coupling zeolitic imidazolate framework-8 (ZIF-8) with Ag₃PO₄, achieving dual-spectral absorption and spatial charge separation. The directional electron transfer from Ag₃PO₄’s conduction band to ZIF-8 effectively suppresses electron-hole recombination, prolonging carrier lifetimes and amplifying ROS production (·O₂⁻/·OH). Synergy with Ag⁺ release further enhances bactericidal efficacy. Incorporated into a cellulose acetate matrix (CAM), the ZIF-8/Ag₃PO₄/CAM film demonstrates 99.06% antibacterial efficiency against meat surface microbiota under simulated sunlight, alongside high transparency. This study proposes a Z-scheme heterojunction strategy to maximize ROS generation efficiency and demonstrates a scalable fabrication approach for active food packaging materials, effectively targeting microbial contamination control and shelf-life prolongation. Full article

This article presents an integrated strategy that couples high-efficiency photocatalytic degradation with low-cost, rapid detection to overcome the main drawbacks of conventional TiO₂-based photocatalysts, including a weak visible-light response, rapid charge–carrier recombination, and reliance on expensive instrumentation for dye concentration detection. Platinum-decorated TiO₂ (Pt/TiO₂) was prepared by photoreduction deposition, and systematic characterization confirmed the successful loading of zero-valent Pt nanoparticles onto the TiO₂ surface, significantly improving charge separation and extending absorption into the visible region. Methylene blue degradation was quantified under ultraviolet (UV) and simulated sunlight; radical-scavenging tests clarified the reaction pathway. In parallel, smartphone images of the reaction mixture were processed in ImageJto extract red–green–blue (RGB) values, which were related to dye concentration through a partial least-squares (PLS) model validated against reference UV–Vis data. Pt/TiO₂ removed 95.0% of methylene blue within 20 min of UV irradiation and 90.2% within 160 min of simulated sunlight—31.8% and 19.1% faster, respectively, than pristine TiO₂. The RGB-based PLS model achieved a coefficient of determination (R²) of 0.961 for the prediction set. By integrating photocatalysis with smartphone-based colorimetry, the proposed method enables rapid monitoring of organic dyes concentration, providing an intelligent and economical platform for industrial wastewater treatment. Full article

In natural photosynthesis, solar energy is utilized to convert water and CO₂ into energy-rich compounds. However, in practice, the maximum quantum efficiency of natural photosynthesis is limited to 6.0%. Conversely, artificial photosynthesis (AP) systems utilize solar energy to convert CO₂ into biosynthetic solar fuels and value-added chemicals. To mimic natural photosystems, AP integrates light-harvesting chemical catalysts with the enzyme-mediated biological catalysis occurring in microorganisms. Similar to solar energy-based optoelectronic power sources, AP has also been recognized as a promising option for reducing carbon emissions generated by the fossil fuel-based power sector. Typical quantum efficiency of AP is 5–10%; in some cases, it exceeds 20%. Recent advancements have focused on nanomaterial biohybrids (NBHs), combining nanomaterial-based photocatalysts/photosensitizers with microorganisms/enzymes for enhanced oxidation/reduction reactions. The synergistic interaction between nanomaterials and microorganisms, facilitated by their comparable size and tunable surface properties, enables improved solar energy absorption, charge separation, and conversion. NBHs offer a versatile platform for sustainable solar energy harvesting and conversion, overcoming the limitations of natural and fully abiotic photosynthesis systems. This review highlights recent breakthroughs in diverse platforms of sunlight and visible light-driven NBH-based AP systems for CO₂ fixation, H₂ production, water splitting, and value-added chemical synthesis. The synthesis strategies, operating mechanisms, and challenges are highlighted. Full article