Search

Comprehensive Summary: Electron transfer is an important way to activate persulfate. Currently, the electrons for persulfate activation mainly originate from organic contaminants or the catalyst itself, which can lead to selective activation of persulfate or oxidation of the catalyst, respectively, and thus become a bottleneck restricting its application. In this work, Cu−doped FeVO4 (Cu−FVO) was prepared, and the results showed that Cu doping can significantly improve the photocatalytic activity and stability of FVO for peroxymonosulfate (PMS) activation. The optimized Cu−FVO/PMS/light system exhibited a high BPA degradation rate that is 4.3 times higher than that of the FVO/PMS/light. This system manifested a broad applicability to various organic contaminants even with complex matrix. Photoelectrochemical analysis and DFT theoretical calculations revealed that Cu doping boosted the photogenerated charge separation and the adsorption of PMS on FVO. Furthermore, Cu doping led to the establishment of an electron transfer channel from Cu−FVO to PMS, through which photogenerated electrons achieved an efficient PMS activation. Meanwhile, holes were consumed by organic contaminants to avoid the oxidation of catalyst. These collectively enhanced the photocatalytic activity and stability of Cu−FVO, which also maintained high catalytic activity even after 20 cycling degradation reactions. [ABSTRACT FROM AUTHOR]

Photoelectrocatalysis has attracted significant attention for water splitting and contaminant degradation. However, the lifetime of photoelectrocatalysis devices is hampered by the severe instability and photocorrosion of the photo‐active nanomaterial on the photoelectrode, which is a key limitation to realizing industrialization. Typically, the conventional protection strategy of photoelectrodes usually suffers from the trade‐off between the photoelectrocatalytic activity and stability. Inspired by biological cell membrane with water channels, here a highly permeable and ultrathin silica coating with ultrasmall straight nanochannels is in situ grown that stabilizes the photoelectrode. These ultrasmall channels boost photoelectrocatalysis by accelerating water transport and reducing the reaction energy within the confined nanochannels. Specifically, the ultrathin coating imparts significant mechanical and structural stability to the photo‐active nanomaterial, thereby preventing its detachment, dissolution, and crystal damage without compromising performance. As a result, the protected photoelectrode exhibits enhanced water splitting activity and excellent stability over 120 h, whereas the photocurrent of the unprotected photoelectrode degrades rapidly. Meanwhile, the coated photoelectrode also exhibits superior photoelectrocatalytic degradation efficiency (>97%), even after the 10th cycle. This strategy is facile and universal and can be extended to construct other stable and high‐performance electrodes for promoting photoelectrocatalysis in practical applications. [ABSTRACT FROM AUTHOR]

Fenton-like degradation of contaminants is considered to be a feasible method for eliminating environmental pollution. In this study, a novel ternary Mg0.8Cu0.2Fe2O4/SiO2/CeO2 nanocomposite was fabricated using a novel ultrasonic-assisted technique, and investigated as a Fenton-like catalyst for the removal of tartrazine (TRZ) dye. The nanocomposite was synthesized by first coating the SiO2 shell around the Mg0.8Cu0.2Fe2O4 core via a Stöber-like process to form Mg0.8Cu0.2Fe2O4/SiO2. Then, a simple ultrasonic-assisted route was used to synthesize Mg0.8Cu0.2Fe2O4/SiO2/CeO2 nanocomposite. This approach provides a simple and environmentally friendly way to produce this material without the use of any additional reductants or organic surfactants. The fabricated sample demonstrated excellent Fenton-like activity. The efficiency of Mg0.8Cu0.2Fe2O4 was significantly enhanced by the incorporation of SiO2 and CeO2, and complete removal of TRZ (30 mg/L) was achieved within 120 min using 0.2 g/L of Mg0.8Cu0.2Fe2O4/SiO2/CeO2. The scavenger test shows that the main active species is the strong oxidizing of hydroxyl radicals (HO•). Consequently, the Fenton-like mechanism of Mg0.8Cu0.2Fe2O4/SiO2/CeO2 is explained based on the coexistence of Fe3+/Fe2+, Cu2+/Cu+, and Ce4+/Ce3+ redox couples. The removal efficiency of TRZ dye remained around 85% after the third recycling run, revealing that the nanocomposite could be employed to eliminate organic contaminants in water treatment. This research opened up a new avenue for expanding the practical application of new-generation Fenton-like catalysts. [ABSTRACT FROM AUTHOR]

The hybrid system BiVO4/g-C3N4 is a prospective photocatalyst because of the favorable mutual alignment of the energy bands of both semiconductors. However, the path of the photocatalytic process is still unclear because of contradictory information in the literature on whether the mechanism of charge carrier separation at the BiVO4/g-C3N4 interface is band-to-band or Z-scheme. In this work, we clarified this issue by comparative photocatalytic studies with the use of systems without a mediator and with different kinds of mediators including Au nanoparticles, fullerene derivatives, and the Fe3+/Fe2+ redox couple. Additionally, the charge transfer dynamics at the BiVO4/g-C3N4 and BiVO4/mediator/g-C3N4 interfaces were investigated by time-resolved photoluminescence (TRPL) measurements, while the influence of the mediator on the surface recombination of the charge carriers was verified by intensity-modulated photocurrent spectroscopy (IMPS). We proved that the charge carrier separation at the BiVO4/g-C3N4 interface occurs according to the mechanism typical for a heterojunction of type II, while the incorporation of the mediator between BiVO4 and g-C3N4 leads to the Z-scheme mechanism. Moreover, a very strong synergetic effect on caffeine (CAF) degradation rate was found for the system BiVO4/Au/g-C3N4 in the presence of Fe3+ ions in the CAF solution. [ABSTRACT FROM AUTHOR]

Graphitic carbon nitride (g‐C3N4) assisted photocatalytic production of hydrogen peroxide (H2O2 has already attracted the interest of many researchers due to its environmental sustainability. Nevertheless, the inherent drawbacks of g‐C3N4 limit its progress. Metal‐free modification strategies, including nanostructure design, defect introduction, doping, and heterojunction construction, have been developed to improve the efficiency of g‐C3N4 photocatalytic H2O2 production. Compared to metal modification, metal‐free strategies avoid the use of precious metals and the leaching of heavy metal ions, which have the advantages of good stability and environmental friendliness. However, a comprehensive review of H2O2 production from g‐C3N4 modified by metal‐free strategies is still lacking. This review first recaps the mechanism of photocatalytic H2O2 production by g‐C3N4, including photoexcitation, carrier separation and redox reactions. Then, the perspective advances in metal‐free modified g‐C3N4 photocatalysts are presented, with the special focus on the kernel connection between different strategies and mechanism based on the pivotal stages of H2O2 production. Subsequently, recent applications of g‐C3N4‐based photocatalysts for in situ generated H2O2, mainly including water purification and organic synthesis, are briefly discussed. Finally, the prospects of g‐C3N4‐based photocatalysts are envisioned with the hope that it will have "something to do" in the field of H2O2 production. [ABSTRACT FROM AUTHOR]

[Display omitted] • (SnFe 2)O x photocatalysts with significant photothermal catalytic degradation capabilities for CTC·HCl. • Mid-gap levels from Fe2+ and Fe3+ ions via IVCT and d – d transitions. • The mid-gap levels lead to distinct photocurrent characteristics under different incident wavelengths. • Electrons activated by visible and near-infrared light undergo cascaded transitions with UV light assistance. We present a comprehensive photocurrent characterization to explore the near-infrared (NIR) response and photothermal effects induced by mid-gap levels in (SnFe 2)O x (SFO) nanoparticles. X -ray photoelectron spectroscopy and diffuse reflectance spectroscopy revealed multiple mid-gap levels due to multivalent Fe ions. The SFO photocatalyst displayed a noticeable temperature rise under NIR irradiation and a considerable photothermal effect across the full solar spectrum during the photocatalytic degradation of chlortetracycline hydrochloride (CTC·HCl). In photothermal catalysis, after 150 min, SFO was able to remove 88% of CTC·HCl (60 mg/L), outperforming photocatalysis (79%) and thermal catalysis (73%). Rapid and slow response processes were observed in the photocurrent characterization under light-emitting diodes of different wavelengths (365–1500 nm), which revealed a clear dependence on the incident wavelength. Furthermore, innovative photocurrent response tests using alternating ultraviolet (UV) and NIR irradiation revealed that, in the presence of mid-gap levels, UV-excited electrons can aid NIR-excited electrons in achieving cascaded electron transitions, enhancing the utilization of NIR-excited electrons. Our findings demonstrate that mid-gap levels effectively improve the utilization of low-energy photons and boost the photocatalytic process through photothermal effects and increased active charge carrier density. [ABSTRACT FROM AUTHOR]

Hydrogen peroxide (H2O2) emerges as an environmentally sustainable oxidant with great potential in diverse fields. However, the efficiency of H2O2 generation via photocatalysis remains suboptimal. Fundamentally, this inefficiency stems from the rapid recombination of photogenerated electron–hole pairs, limited surface or interface activity, restricted solar light absorption, and poor selectivity. Here, we discuss the fundamental mechanisms of photocatalytic H2O2 generation over the key material systems and highlight the most effective design strategies to address the unmet challenges faced by these systems. This review not only discusses fundamental insights into the mechanisms of photocatalytic H2O2 generation but also provides perspectives on future directions for the development of photocatalytic materials with high-efficiency and stability in generating H2O2. [ABSTRACT FROM AUTHOR]

A radiation-self-Fenton system without the addition of H2O2 was developed for the efficient degradation of organic pollutants. We synthesized nickel-based metal–organic framework (Ni-BTC) as a catalyst for the in-situ generation of abundant hydroxyl radicals (·OH) and H2O2 under X-ray excitation, and the latter was further converted to ·OH in the Fenton reaction to synergistically accelerate the Methylene blue (MB) degradation. The embedded nickel sites and confined layered structure contributed to the stabilization and enrichment of ·OH within the framework. Consequently, the system could completely decolorize 150 mL of MB (20 mg/L) by absorbing 90 Gy dose. This study provided a novel technology for wastewater treatment. [ABSTRACT FROM AUTHOR]

Defect engineering is an emerging technology for tailoring nanomaterials' characteristics and catalytic performance in various applications. Recently, defect‐engineered nanoparticles have emerged as highly researched materials in catalytic applications because of their exceptional redox reaction capabilities and physicochemical and optical properties. The properties of nanomaterials can be readily adjusted by controlling the nature and concentration of defects within the nanoparticles, avoiding the need for intricate design strategies. This review investigates defect engineering in nanocatalysts, including the design, fabrication, and applications. Initially, the various categories and strategies of nanomaterial defects and their impacts on the nanocatalysts' electronic and surface properties, catalytic activity, selectivity, and stability are summarized. Then, the catalytic processes and their uses, including gas sensing, hydrogen (H2) evolutions, water splitting, reductions of carbon dioxide (CO2) and nitrogen to value‐aided products, pollutant degradation, and biomedical (oncotherapy, antibacterial and wound healing, and biomolecular sensing) applications are discussed. Finally, the limitations in defect engineering and the prospective paths for allowing the logical design and optimization of nanocatalytic materials for long‐term and efficient applications are also examined. This comprehensive review gives unique insights into the current state of defect engineering in nanocatalysts and inspires future research on exploiting shortcomings to improve and customize catalytic performance. [ABSTRACT FROM AUTHOR]

To solve environmental-related issues (wastewater remediation, energy conservation and air purification) caused by rapid urbanization and industrialization, synthesis of novel and modified nanostructured photocatalyst has received increasing attention in recent years. We herein report the facile synthesis of in situ nitrogen-doped chemically anchored TiO2 with graphene through sol–gel method. The structural analysis using X-ray diffraction showed that the crystalline nitrogen-doped graphene-titanium dioxide (N-GT) nanocomposite is mainly composed of anatase with minor brookite phase. Raman spectroscopy revealed the graphene characteristic band presence at low intensity level in addition to the main bands of anatase TiO2. X-ray photoelectron spectroscopy analysis disclosed the chemical bonding of TiO2 with graphene via Ti–O-C linkage, also the substitution of nitrogen dopant in both TiO2 lattice and into the skeleton of graphene nanoflakes. UV–Vis absorption spectroscopy analysis established that the modified material can efficiently absorb the longer wavelength range photons due to its narrowed band gap. The N0.06-GT material showed the highest degradation efficiency over methylene blue (MB, ∼98%) under UV and sulfamethoxazole (SMX, ∼ 90.0%) under visible light irradiation. The increased activity of the composite is credited to the synergistic effect of high surface area via greater adsorption capacity, narrowed band gap via increased photon absorption, and reduced e−/h+ recombination via good electron acceptability of graphene nanoflakes and defect sites (Ti3+ and oxygen vacancy (Vo)). The ROS experiments further depict that primarily hydroxyl radicals (OH•) and superoxide anions (O2•−) are responsible for the pollutant degradation in the process redox reactions. In summary, our findings specify new insight into the fabrication of this new material whose efficiency can be further tested in applications like H2 production, CO2 conversion to value-added products, and in energy conservation and storage. [ABSTRACT FROM AUTHOR]

Abstract Photoelectrocatalysis has attracted significant attention for water splitting and contaminant degradation. However, the lifetime of photoelectrocatalysis devices is hampered by the severe instability and photocorrosion of the photo‐active nanomaterial on the photoelectrode, which is a key limitation to realizing industrialization. Typically, the conventional protection strategy of photoelectrodes usually suffers from the trade‐off between the photoelectrocatalytic activity and stability. Inspired by biological cell membrane with water channels, here a highly permeable and ultrathin silica coating with ultrasmall straight nanochannels is in situ grown that stabilizes the photoelectrode. These ultrasmall channels boost photoelectrocatalysis by accelerating water transport and reducing the reaction energy within the confined nanochannels. Specifically, the ultrathin coating imparts significant mechanical and structural stability to the photo‐active nanomaterial, thereby preventing its detachment, dissolution, and crystal damage without compromising performance. As a result, the protected photoelectrode exhibits enhanced water splitting activity and excellent stability over 120 h, whereas the photocurrent of the unprotected photoelectrode degrades rapidly. Meanwhile, the coated photoelectrode also exhibits superior photoelectrocatalytic degradation efficiency (>97%), even after the 10th cycle. This strategy is facile and universal and can be extended to construct other stable and high‐performance electrodes for promoting photoelectrocatalysis in practical applications.

This article explores the development and applications of a Cu3N/GCE-based sensor using differential pulse voltammetry (DPV) for selective uric acid (UA) detection in clinical analysis. The sensor achieves a limit of detection (LOD) of 2.57 × 10−8 M and a quantification limit (QL) of 8.102 × 10−8 M, demonstrating its capability to precisely quantify minute UA concentrations. With rapid responsiveness and reusability over 25 days, it offers cost-effective monitoring of UA levels, even in complex sample matrices. Cu3N also exhibits high efficiency in degrading methylene blue (MB), achieving 87.7% degradation under optimized conditions, suggesting its potential as a photocatalyst for environmental remediation, particularly in dye degradation processes. Overall, Cu3N-based technologies show promise in sensitive UA detection for clinical diagnostics, environmental remediation, and industrial catalysis, highlighting its versatility and broad applicability across scientific and practical domains.

Green and clean photocatalytic technology has been extensively applied to degrade environmental pollutants and produce renewable energy, which is an important mean to solve environmental and energy problems. However, limited to the cost and efficiency of photocatalysts, it is difficult to realize large-scale application. In recent years, the single-atom photocatalysts (SAPCs) have added new vitality into this field. SAPCs have the active homogeneous centers, heterogeneous structures, stability, high catalytic activity and selectivity properties. The related researches on its synthesis, characterization and application have become a hot spot in many fields. In this review, the photocatalytic H2 production, CO2 reduction, nitrogen fixation, NOx removal, volatile organic compounds removal, pollutant degradation, reduction of radionuclides and heavy metal ions using SAPCs are reviewed. The advantages and disadvantages of the six kinds of SAPCs substrates are analyzed, and design strategies are carefully summarized. The mechanisms of photocatalysis, isolated-site reactions, photogenerated e−-h+ transfer and the construction of efficient photoactivation cycles are discussed. Finally, the future development trend of SAPCs is prospected. This review will provide a reference for the design of high efficiency SAPCs. The structures, characteristics and synthesis of SAPCs with different substrates are reviewed. The applications of SAPCs and their photocatalytic removal for different pollutants are introduced. The photocatalytic reaction processes and mechanisms for different pollutants are discussed. The development direction and challenges of SAPCs in the field of environmental energy are prospected. [ABSTRACT FROM AUTHOR]

New protein resources can be developed to alleviate the shortage of protein in the feed industry. Photosynthetic bacteria (PSB) can serve as unique microbial protein sources. Among them, the light environment is a crucial influencing factor in the growth and metabolism of PSB. In this study, the light supply strategies were employed to enhance the growth of Rhodopseudomonas palustris (R. palustris) and the synthesis of single-cell protein (SCP) in the wastewater resource systems of PSB. Additionally, a systematic analysis was made on the correlations between substance synthesis and pollutant degradation under different light supply strategies. The results indicated that a full spectrum of light was more conducive to the accumulation of biomass and protein concentration in R. palustris, compared with the segmented spectra. Under incandescent lamp and white LED irradiation, the highest biomass concentration, daily bacterial production, bacterial yield, and protein concentration reached (1 023.18±201.17) mg/L, (0.32±0.10) g/(L·d), (0.31±0.03) mg/mg and (555.66±9.18) mg/L, respectively. These values increased by 37.26%-43.79%, 108.82%-137.92%, 42.01%-91.85%, and 24.77%-33.47%, respectively, compared with the blue and green light groups (P<0.05). Moderate light intensity was favored to accumulate biomass and protein concentration, while excessive or low intensity was detrimental to the accumulation of high-value products by R. palustris. Specifically, under a light intensity of 120 μmol/(m² ·s), the highest biomass concentration, daily bacterial production, bacterial yield, and protein concentration reached (1 646.12±2.47) mg/L, (0.77±0.01) g/(L·d), (0.44±0.05) mg/mg and (803.59±2.62) mg/L, respectively. There was an increase of 60.23%-140.19% in biomass and an increase of 61.90%-94.18% in protein concentration, compared with the 0 μmol/(m² ·s) (control) and 240 μmol/(m² ·s) groups (P<0.05). Intermittent light exhibited significant advantages over continuous light. An appropriate light cycle was selected to significantly promote the growth and protein synthesis of R. palustris. In the condition of 18 L/6 D, the highest biomass concentration, daily bacterial production, protein concentration, and nitrogen conversion efficiency reached (1 140.56±19.72) mg/L, (0.32±0.02) g/(L·d), (506.53±48.20) mg/L, and (1.77±0.35) mg/mg, respectively. There were increases by 17.06%-93.21%, 54.43%-299.93%, 24.35%-43.88% and 38.78%, respectively, compared with the 3 L/21 D and 9 L/15 D groups (P<0.05). The 3 L/21 D group exhibited the highest protein content at 67.47%, indicating an increase of 21.96%-44.54%, compared with all the other experimental groups (P<0.05). Additionally, under conditions of incandescent light, the light intensity of 120 μmol/(m² ·s) and photoperiod of 18 L/6 D, COD and NH4+ -N removal efficiencies reached 72.03%-78.40%. Furthermore, there were significant negative correlations between light intensity and spectrum with the protein content and concentration. Conversely, the photoperiod shared a significant positive correlation with protein concentration. Therefore, the photoperiod can be expected to enhance the production of SCP by R. palustris. Its mechanism involves the direct regulation of PSB growth and metabolism by the light/dark cycle. During the light period, PSB pigments capture photons through photoreactions, driving electron transfer, generating electrical energy, and ultimately converting it into ATP; Simultaneously, the Calvin cycle efficiency is enhanced, leading to the accumulation of cell growth and SCP. During the dark period, PSB cells focus on the division process, increasing overall biomass. This research can provide innovative insights to enhance the SCP synthesis in wastewater systems using PSB. [ABSTRACT FROM AUTHOR]

Epoxiconazole (EPO) is classified as a persistent organic pollutant due to its ability to persist in the environment for prolonged periods. Its degradation is pivotal in mitigating its environmental impact. This investigation focuses on assessing the degradation of EPO using various methodologies, namely Fenton, photo-Fenton, solar photo-Fenton, and solar photolysis, conducted in both Milli-Q water and groundwater. These experiments encompassed evaluations at both the standard pH typically used in photo-Fenton reactions and the natural pH levels inherent to the respective aqueous environments. Additionally, EPO degradation products were analyzed after a 60-min reaction. Notably, in systems utilizing groundwater, the inclusion of additional iron was unnecessary, as the naturally occurring iron content in the groundwater facilitated the intended processes. Specifically, in Milli-Q water, solar photo-Fenton demonstrated an EPO degradation efficiency of 97%. Furthermore, the substitution of Milli-Q water with groundwater in Fenton-like processes did not significantly affect the efficacy of EPO degradation. These findings underscore the potential of solar photo-Fenton as an economically viable and environmentally sustainable strategy for EPO degradation. [ABSTRACT FROM AUTHOR]

Metal halide perovskite photocatalysts (MHPPs) exhibit unique electronic and optical properties, making them attractive for diverse photocatalytic applications. Their exceptional properties can be tuned by adjusting the halide ion or cation size. MHPPs have shown promise in solar energy conversion, water splitting, and air purification. However, synthesis and stability challenges hinder practical applications. This comprehensive review presents the properties, applications, and challenges of MHPPs, proposing future research directions. Although dogged by many issues, MHPPs demonstrate remarkable charge separation capabilities, rendering them advantageous in many photocatalytic applications. They offer flexibility through the manipulation of elements, crystal structures, surface chemistry, and morphologies. The review also discusses Type-II, Z-scheme heterojunction, as well as the emerging S-scheme heterojunction, which is a recent, improved alternative. Consolidating current knowledge, this review serves as a valuable resource, providing insights into MHPPs' potential and guiding further advancements. MHPPs have significant applications in water splitting, air purification, pollutant degradation, and energy conversion. Their unique properties and versatility enable tailored optimization. This overview is a crucial reference for researchers, engineers, scholars, and students, inspiring innovative and sustainable photocatalytic solutions. [ABSTRACT FROM AUTHOR]

The Fenton reaction refers to the reaction in which ferrous ions (Fe2+) produce hydroxyl radicals and other reactive oxidizing substances by decomposing hydrogen peroxide (H2O2). This paper reviews the mechanism, application system, and materials employed in the Fenton reaction including conventional homogeneous and non‐homogeneous Fenton reactions as well as photo‐, electrically‐, ultrasonically‐, and piezoelectrically‐triggered Fenton reactions, and summarizes the applications in the degradation of soil oil pollutions, landfill leachate, textile wastewater, and antibiotics from a practical point of view. The mineralization paths of typical pollutant are elucidated with relevant case studies. The paper concludes with a summary and outlook of the further development of Fenton‐like reactions. [ABSTRACT FROM AUTHOR]

The main aim of the present study was to determine the impact of the Silica (SiO2) on the photocatalytic activity of Titanium dioxide (TiO2) nano composite at various circumstance of preparation. Over the past few decades, there has been an increasing trend toward researching novel photocatalysts for water purification and protecting the environment from pollution. These organic pollutants have been degraded using various methods, including sophisticated heterogeneous photocatalysis (PHCs) using titanium dioxide (TiO2). One of the most promising technologies seems to be using a TiO2 photocatalyst. An appropriate architecture that reduces electron loss during the excitation state and promotes the absorption of photons is necessary to maintain the high efficiency of the TiO2 photocatalyst in heterogeneous PHCs reactions. The heterogeneous PHCs under UV–visible solar light must be significantly improved to further enhance the flow of photo-induced charge carriers during the excitation state. Recently, the intriguing and distinctive characteristics of binary oxide photocatalyst systems or silica (SiO2) doping have attracted much attention and have become a favorite subject of study for many scientific organizations. Compared to pure TiO2, the features of this SiO2 doping were found to improve the photocatalytic (PHC) behavior by increasing the surface area of the TiO2 photocatalyst system. Therefore, this work critically reviews the modification of TiO2/SiO2 photocatalysts for pollutant degradation. [ABSTRACT FROM AUTHOR]

Groundwater is the only source of clean water for human use in much of the world, but contaminants from the home, business, and agriculture-such as fertilizers and pesticides-can quickly contaminate it. The main objective of the current work was to investigate the photocatalytic removal of the herbicide 2,4-Dichlorophenoxyacetic acid (2,4-D) from an aqueous medium utilizing environmentally friendly zinc oxide nanoparticles. One of the main areas of research has been the possible use of zinc oxide (ZnO) nanoparticles in antifungal, antibacterial, and optical applications. Due to their unique qualities, the well-known nanoparticles utilized in nanotechnology and nanoscience have a wide range of practical applications in the chemical, pharmaceutical, medical, and rural sectors. These particles are used to degrade contaminants during synthetic production. Due to the availability of dangerous synthetic compounds and the outrageous climatic openness in these nanoparticles' physical and substance growth, eco-friendly approaches to utilizing plants have been established. The study includes a brief history of the production of zinc oxide nanoparticles and their application in the pollutant 2,4 D degrading process. This study highlights the use of neem extract in the manufacture of zinc oxide nanoparticles and their application in the removal of contaminants. [ABSTRACT FROM AUTHOR]

Designing photocatalysts with p-n heterojunction structures is an effective way to boost the separation of photogenerated carriers and stimulate the photocatalytic degradation activity. Herein, an efficient visible-light responsive AgI/BiSI p-n heterojunction photocatalyst was successfully constructed. X-ray photoelectron spectroscopy (XPS), photoluminescence (PL) spectroscopy, and electrochemical measurements confirmed that the AgI/BiSI p-n heterojunction structure was beneficial to the separation and transfer of photogenerated carriers, promoting the generation of main active species (•O2− and h+). Furthermore, the photocatalytic degradation rate constants of Acid Red 1 (0.4699 min−1) and metronidazole (0.0730 min−1) over the optimal AgI/BiSI were about 8.4 and 3.0 times higher than those over pure AgI, respectively. This work provides a heterojunction engineering strategy to design high-efficient photocatalysts for the degradation of refractory organic pollutants.

The hybrid system BiVO4/g-C3N4 is a prospective photocatalyst because of the favorable mutual alignment of the energy bands of both semiconductors. However, the path of the photocatalytic process is still unclear because of contradictory information in the literature on whether the mechanism of charge carrier separation at the BiVO4/g-C3N4 interface is band-to-band or Z-scheme. In this work, we clarified this issue by comparative photocatalytic studies with the use of systems without a mediator and with different kinds of mediators including Au nanoparticles, fullerene derivatives, and the Fe3+/Fe2+ redox couple. Additionally, the charge transfer dynamics at the BiVO4/g-C3N4 and BiVO4/mediator/g-C3N4 interfaces were investigated by time-resolved photoluminescence (TRPL) measurements, while the influence of the mediator on the surface recombination of the charge carriers was verified by intensity-modulated photocurrent spectroscopy (IMPS). We proved that the charge carrier separation at the BiVO4/g-C3N4 interface occurs according to the mechanism typical for a heterojunction of type II, while the incorporation of the mediator between BiVO4 and g-C3N4 leads to the Z-scheme mechanism. Moreover, a very strong synergetic effect on caffeine (CAF) degradation rate was found for the system BiVO4/Au/g-C3N4 in the presence of Fe3+ ions in the CAF solution.

The degradation of organic dye contaminants provides a promising approach for mitigating pollutants and addressing wastewater treatment. Despite the extensive research and development of various photocatalysts with the objective of effectively degrading organic pollutants, the challenge still persists. This paper introduces a facile and sustainable technique for synthesizing silver nanoparticles (AgNPs) using kiwi fruit peel, as a bio-waste resource. A comprehensive analysis of the AgNPs was conducted using microscopic and spectroscopic techniques. The observation of a color change and measurement of UV–vis absorbance at 435 nm confirmed the development of AgNPs. FE-SEM examination demonstrated that AgNPs have homogeneous distribution of cubic structure with 10 to 70 nm. The AgNPs demonstrated photocatalytic degradation potential of 94.2% for Congo red (CR) under visible light irradiation. Additionally, synthesized AgNPs exhibited concentration depended bactericidal activity. In conclusion, as synthesized AgNPs can efficiently purify wastewater and suppress pathogens due to their strong degrading activity, reusability, and antibacterial actions. [ABSTRACT FROM AUTHOR]

As the initial stage of the sewage treatment system, the degradation of pollutants inevitably involves an entropy change process. Microorganisms play a vital role, where they interact with pollutants and constantly adjust own ecosystem. However, there is a lack of research on the entropy change and external dissipation processes within the sewer system. In this study, considering the characteristics of microbial population changes in the biofilm within the urban sewage pipe network, entropy theory is applied to characterize the attributes of different microorganisms. Through revealing the entropy change of the microbial population and chemical composition, a coupling relationship between the functional bacteria diversity, organic substances composition, and external dissipation in the pipeline network is proposed. The results show that the changes of nutrient availability, microbial community structure, and environmental conditions all affect the changes of information entropy in the sewer network. This study is critical for assessing the understanding of ecological dynamics and energy flows within these systems and can help researchers and operation managers develop strategies to optimize wastewater treatment processes, mitigate environmental impacts, and promote sustainable management practices. [ABSTRACT FROM AUTHOR]

The removal of color-causing compounds from wastewater is a significant challenge that industries encounter due to their toxic, carcinogenic, and harmful properties. Despite the extensive research and development of various techniques with the objective of effectively degrading color pollutants, the challenge still persists. This paper introduces a simple technique for producing iron oxide nanoparticles (Fe2O3 NPs) using orange fruit peel for sustainable dye degradation in aqueous environment. The observation of color change and the measurement of UV–visible absorbance at 240 nm provided a confirmation for the development of Fe2O3 NPs. Transmission electron microscopy examination demonstrated that the Fe2O3 NPs have an agglomerated distribution and forming spherical structures with size ranging from 25–80 nm. Energy-dispersive X-ray spectroscopy analysis supported the existence of Fe and O. Fourier transform infrared spectroscopy conducted to investigate the involvement of orange peel extract in the reduction, capping, and synthesis of Fe2O3 NPs from the precursor salt. Fe2O3 NPs showed a photocatalytic remediation of 97%, for methylene blue under visible light irradiation. Additionally, prepared NPs exhibited concentration depended biofilm inhibition action against E. coli and S. aureus. In conclusion, Fe2O3 NPs can efficiently purify water and suppress pathogens due to their strong degrading activity, reusability, and biofilm inhibition property. [ABSTRACT FROM AUTHOR]

The public widely uses Paracetamol (PCT) as an analgesic drug to reduce pain and fever symptoms in the human body. The COVID-19 pandemic has led to an increase in PCT consumption, resulting in its presence in water bodies and establishing it as a common aquatic environmental pollutant. Conventional methods for PCT removal rely on chemical treatments, which necessitate harsh reaction conditions and incur high operational costs. This study aims to investigate the potential for PCT degradation within the anode environment of the Microbial Fuel Cell (MFC) system, using a consortium of bacteria isolated from sewage sludge. The initial PCT concentration and the pH of the anode environment were varied. The results showed that PCT degradation occurred within 72 hours. The highest PCT removal rate was achieved at elevated concentrations, specifically 28.54 ± 18.84% for an initial PCT concentration of 31.45 mg/L. Furthermore, the pH levels of the anode environment were observed to influence PCT degradation, with the highest degradation rate recorded at 48.69 ± 0.86% at a pH of 8.2. In this study, the highest average power density reached was 1174.42 mW/m2 with an external resistance of 1000 Ω at an initial PCT concentration of 31.45 mg/L. Microbial community analysis was conducted, revealing that Burkholderia sp. dominated the reactor containing PCT. These findings offer valuable insights for the development of more efficient technologies for the removal of PCT from pharmaceutical wastewater using natural microbial communities.

Abstract Microbial flora plays an important role in microorganism-enhanced technology. The pollutant degradation ability and viable counts of these agents are crucial to guarantee their practical application. In this study, an efficient pollutant-degrading microbial flora was screened, its medium components and culture conditions were optimized, and its effect was verified in zeolite trickling filter towers. After a 24 h culture under the optimal conditions, the viable count reached 4.76 × 109 cfu/mL, with the degradation rates of ammonia nitrogen (NH4 +-N), nitrate nitrogen (NO3 −-N), total nitrogen (TN), total phosphorus (TP), and chemical oxygen demand (COD) increased to 93.5%, 100%, 68.3%, 32.6%, and 85%, respectively. After optimizing the feeding strategy, the concentration of viable bacteria reached 5.80 × 109 cfu/mL. In the application effect verification experiment, the degradation rates of NH4 +-N, TN, TP, and COD in the experimental group reached 96.69%, 75.18%, 73.82%, and 90.83%, respectively, showing a significant improvement compared to the results of the control group. The main components in the control group were Dokdonella, Brevundimonas, Alishewanella, Rhodobacter, Pseudoxanthomonas, and Thauera, whereas those in the experimental group were Dokdonella, Proteocatella, Rhodobacter, Dechlomonas, and Nitrospira. Proteocatella, Dechlomonas, and Nitrosra, which were unique to the experimental group, are common bacteria used for nitrogen and phosphorus removal. This explains the difference in the sewage treatment capacity between the two groups. This study provides an alternative sewage treatment microbial flora with a reasonable production cost and high degradation efficiency for NH4 +-N, TN, TP, and COD.

In this research, we present SmMnO3/Sm2O3 nanocomposites as a novel ferromagnetic photocatalyst, synthesized through a straightforward sol-gel Pechini method utilizing citric acid and oxalic acid as fuels. Achieving the desired morphology involved varying the fuel type and calcination temperature. Comprehensive physicochemical characterizations were conducted using X-ray diffraction analysis (XRD), scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FTIR), vibrating sample magnetometer (VSM), diffuse reflectance spectroscopy (DRS), and Brunauer-Emmett-Teller BET. With a band gap of 2.1 eV in the visible range, the SmMnO3/Sm2O3 nanocomposites exhibit promising optical properties. The photocatalytic prowess of these nanocomposites was systematically assessed against Malachite Green and Acid Red, with optimization of key parameters such as light source, pollutant concentration, and catalyst dosage. Notably, the peak photocatalytic activity was observed for Malachite Green, achieving an impressive 96% degradation under visible light within 120 min. The elucidation of the photocatalytic mechanism employed scavengers, revealing the pivotal role of OH• in the photodegradation process. Recycling experiments demonstrated consistent and acceptable results over five cycles, affirming the recyclability and durability of the SmMnO3/Sm2O3 nanocomposites. This study introduces a novel ferromagnetic photocatalyst with notable photocatalytic efficiency, emphasizing its potential applications in environmental remediation. The novelty of this work lies in the introduction of a new nanocomposite for photocatalysis in visible light, achieving high efficiency within a short time frame of 120 min.

According to the typical Sillén-structured BiOBr, a simple solvothermal method was used to successfully synthesise Sillén-structured bimetallic oxyhalide CdBiO2Br with the existence of 1-hexadecyl-3-methylimidazolium bromide ([C16mim]Br), a kind of reactive ionic liquid. The introduction of the metal cadmium, which can form Sillén-structured bimetallic oxyhalide, made the alternating structure of BiOBr originally [Bi2O2]2+ and bilayer Br- modified to that of [CdBiO2]+ and monolayer Br-. So that the distance between layer and layer is greatly shortened, which facilitates the migration and separation of photogenerated carriers and promotes the generation of more reactive oxygen species. After modification, the band positions of CdBiO2Br materials can make more full use of visible light and more favourable utilisation of solar resources. As confirmed by radical trapping analysis and ESR analysis, superoxide radical (·O2−) and hole (h+) acted the major part during photocatalysis. The possible intermediate products that appeared during the degradation progress were analyzed by LC–MS. Moreover, the generation of superoxide ions was quantitatively analyzed by nitroblue tetrazolium chloride (NBT). In this paper, we present an ultra-thin layered material for visible light catalysis, which enlightens a feasible scheme for the research and development of new layered photocatalytic materials. [ABSTRACT FROM AUTHOR]

The push for advanced water treatment techniques has led to significant growth in research focusing on ozonation catalysis, aiming to enhance pollutant degradation efficiency and energy conservation. Conventional ozonation methods, although practical, face limitations in specific pollutant degradation and require excessive energy inputs. Introducing catalysis to ozonation can potentially overcome these challenges, driving the research frontier toward innovative catalyst materials and optimized procedures. This review delves deep into the fundamentals of catalytic ozonation, emphasizing its advantages and critical role in advanced water treatment solutions. To examine emerging trends, spotlighting state-of-the-art catalysts and their influence on improving ozonation outcomes. The future perspectives of catalytic ozonation are projected, highlighting its potential to revolutionize water treatment paradigms, harnessing the balance of energy efficiency and robust pollutant removal. [ABSTRACT FROM AUTHOR]

FeOOH quantum dots (QDs) were successfully anchored on 2D BiOBr nanosheets as composite photo‐Fenton catalysts by a simple precipitation and impregnation method. Using Rhodamine B (RhB) as an organic dye model, the photo‐Fenton catalytic activity of the composite catalyst was significantly higher than that of BiOBr and FeOOH. Among them, 1.8 % FeOOH/BiOBr has the highest photo‐Fenton catalytic activity. The main reason is that the interface effect between FeOOH and BiOBr can enable photogenerated electrons to rapidly transfer from the surface of BiOBr to FeOOH to participate in the Fe3+/Fe2+ cycle. Meanwhile, the quantum size of FeOOH increases the density of active sites on the surface of the composite catalyst. The influence of external factors on the catalytic activity of the catalyst was also verified. Finally, the electron transfer direction and main active species (h+, ⋅O2−) of the composite catalyst were discussed by electrochemical analysis and radical trapping experiments, and a reasonable catalytic degradation mechanism was proposed. [ABSTRACT FROM AUTHOR]

[Display omitted] • Hydrothermally synthesized BTO nanoparticles enable multimodal energy harvesting. • The piezo/pyro/phototronic synergistic effect boosts the photocatalytic performance. • The photo/piezo/pyrocatalytic degradation reaction rate of RhB reaches 0.1534 min−1. • BTO could harvest surrounding energy to restore environmental water resources. Solar-driven pollutants degradation is an important way for green wastewater treatment, but it is still limited by the intermittent solar flux. Here, we have prepared piezoelectric Bi 4 Ti 3 O 12 (BTO) nanosheets with abundant physical properties, which can convert extensive solar energy, mechanical energy and temperature variation energy into electrical and chemical energy. It can be used for round-the-clock wastewater treatment by harvesting multi-modal energy. More importantly, the degradation rate of piezoelectric nanosheets can reach 153.4 × 10-3 min−1, and nanosheets can degrade many organic pollutants. In addition, we fabricate porous foam catalysts based on BTO-polydimethylsiloxane (PDMS) composite to prevent secondary contamination. Our results suggest that BTO nanosheets with photoelectric, piezoelectric and pyroelectric catalysis offer a potential approach for round-the-clock wastewater degradation by harvesting solar energy, ambient mechanical energy, and cyclic thermal energy. [ABSTRACT FROM AUTHOR]

Flavin mononucleotide (FMN) is a dye belonging to the flavin family. These dyes produce photosensitized degradation of organic compounds via reaction with the excited states of the dye or with reactive oxygen species photogenerated from the triplet of the dye. This article presents a new polymeric dye (FMN–CS) composed of the photosensitizer FMN covalently bonded to chitosan polysaccharide (CS). FMN–CS obtained has a molecular weight of 230 × 103 g mol−1 and a deacetylation degree of 74.8%. The polymeric dye is an environmentally friendly polymer with spectroscopic and physicochemical properties similar to those of FMN and CS, respectively. Moreover, under sunlight, it is capable of generating 1O2 with a quantum yield of 0.31. FMN–CS, like CS, is insoluble in basic media. This allows easy recovery of the polymeric dye once the photosensitized process has been carried out and makes FMN–CS a suitable photosensitizer for the degradation of pollutants in contaminated waters. To evaluate whether FMN–CS may be used for pollutant degradation, the photosensitized degradation of two trihydroxybenzenes by FMN–CS was studied. [ABSTRACT FROM AUTHOR]

Herein, a novel visible-light-responsive photocatalyst with high efficiency was firstly synthesized at room temperature. The mild synthetic method resulted in a uniform spherical triazine-based covalent organic framework (TrCOF2) with ultra-high specific surface area as well as chemical stability. Due to the synergistic effect between the self-assembled uniform spherical structure and the abundant triazine-based structure, photoelectron–hole pairs were efficiently separated and migrated on the catalysts. On this basis, TrCOF2 was successfully applied to efficiently degrade bisphenol A (BPA). More than 98% of BPA was deraded after 60 min of visible light treatment, where the active specie of •O2− played a vital role during the degradation of BPA. The holes of TrCOF2 could produce O2 by direct reaction with water or hydroxide ions. Simultaneously, photoelectrons can be captured by O2 to generate •O2−. Moreover, density functional theory (DFT) calculations proved the outstanding ability of the exciting electronic conductivity. Remarkably, a reasonable photocatalytic mechanism for TrCOF2 catalysts was proposed. This research can provide a facile strategy for the synthesis of TrCOFs catalysts at room temperature, which unfolds broad application prospects in the environmental field. [ABSTRACT FROM AUTHOR]

The p–n heterojunction nanocatalyst was successfully synthesized by decorating the surface of ZnO nanorods with CuO by using a low-temperature synthesis method. It was used as the driving force for the removal of tetracycline (TC) in water with mechanical stirring. Different ratios of ZnO/CuO piezoelectric nanocatalysts were examined. The nanoscale ZnO/CuO catalyst achieved a 98% removal rate of TC in water after 120 min. The main active species for TC degradation were identified as hydroxyl radicals (•OH) and superoxide radicals (•O2–) by quenching experiments. The piezoelectric current generated by ZnO/CuO-1.5 was found to be 3.1 and 6.2 times higher than those of pure ZnO and CuO, respectively, due to the formation of a p–n heterojunction structure and built-in electric field situation. The facile and low-temperature synthesis process of the ZnO/CuO nanocatalyst with superior removal rates provides practical support for large-scale application in wastewater treatment. [ABSTRACT FROM AUTHOR]

In the present work, undoped, (Cu, In) doped and co-doped ZnO nanoparticles are successfully prepared by co‐precipitation technique. The molar concentrations of dopant elements are 2% for both Cu and In doping, and 1%–1% for the Cu/In co-doping. Energy dispersive X-ray (EDX) analysis confirms the chemical composition of the prepared nanoparticles, and proves the effective introduction of dopant elements into the ZnO host lattice. The X-ray diffraction (XRD) analysis indicates the formation of single-phase hexagonal wurtzite structure for the all synthesized samples. The morphological investigation shows change of ZnO nanoparticles from nanotubes to spherical shape under the effect of doping and co-doping. The reflectance spectra show red shift of the absorption edge as a result of Cu doping and Cu/In co-doping effect. The PL spectra confirm emission bands in the visible rage related to the presence of defects, such as oxygen vacancies, as well as shallow trap levels near the conduction band edge. These oxygen deficiencies have an important effect on the charge carrier transport, resulting in the enhancement of electrical conductivity in doped and co-doped ZnO. In addition, photocatalytic performance experiments prove that the photocatalytic activity of ZnO, in the degradation of amido black 10B dye, is significantly enhanced via (Cu, In) doping and co-doping. [ABSTRACT FROM AUTHOR]

Microbial flora plays an important role in microorganism-enhanced technology. The pollutant degradation ability and viable counts of these agents are crucial to guarantee their practical application. In this study, an efficient pollutant-degrading microbial flora was screened, its medium components and culture conditions were optimized, and its effect was verified in zeolite trickling filter towers. After a 24 h culture under the optimal conditions, the viable count reached 4.76 × 109 cfu/mL, with the degradation rates of ammonia nitrogen (NH4+-N), nitrate nitrogen (NO3−-N), total nitrogen (TN), total phosphorus (TP), and chemical oxygen demand (COD) increased to 93.5%, 100%, 68.3%, 32.6%, and 85%, respectively. After optimizing the feeding strategy, the concentration of viable bacteria reached 5.80 × 109 cfu/mL. In the application effect verification experiment, the degradation rates of NH4+-N, TN, TP, and COD in the experimental group reached 96.69%, 75.18%, 73.82%, and 90.83%, respectively, showing a significant improvement compared to the results of the control group. The main components in the control group were Dokdonella, Brevundimonas, Alishewanella, Rhodobacter, Pseudoxanthomonas, and Thauera, whereas those in the experimental group were Dokdonella, Proteocatella, Rhodobacter, Dechlomonas, and Nitrospira. Proteocatella, Dechlomonas, and Nitrosra, which were unique to the experimental group, are common bacteria used for nitrogen and phosphorus removal. This explains the difference in the sewage treatment capacity between the two groups. This study provides an alternative sewage treatment microbial flora with a reasonable production cost and high degradation efficiency for NH4+-N, TN, TP, and COD. Keypoints: A mixed-bacteria group with a high degradation rate of NH4+-N, TN, TP, and COD was screened. The viable cell concentration and pollutant degradation efficiency of the screened microbial flora was increased significantly by optimizing its cultivation conditions. Increased pollutant degradation efficiency was verified in a zeolite trickling filter tower and explained by the microbial composition of the screened microbial flora. [ABSTRACT FROM AUTHOR]

Nanozymes can be used as favorable substitutes for natural enzymes because of their strong catalytic activity and good stability. At the same time, research on single‐atom catalysts (SACs) with isolated metal atoms as active centers is also in full swing, showing excellent performance in a variety of catalytic reactions. With the in‐depth study of SACs, people have a comprehensive understanding of them and put forward the concept of single‐atom nanozymes (SAzymes) by combining nanozymes with SACs. As a new type of nanomaterial, SAzymes have attracted great interest due to their remarkable catalytic activity and rapid energy conversion. However, most applications of SAzymes are mainly in the fields of biomedicine and biosensing, and less research has been done in the field of the environment. Based on the amazing ability of nanozymes to detect and degrade pollutants, SAzymes are also used in the environmental field, and even they will show better capabilities. This review mainly analyses common transition metal‐based SAzymes and describes their applications in the field of environmental pollutants. [ABSTRACT FROM AUTHOR]

Based on microalgae biological treatment technology, the microalgae-bacteria symbiosis system can not only efficiently realize sewage recycling, but also utilize the interactions between microalgae and bacteria to enhance the pollutant removal capacity of the treatment system and recover synthetic biomass. Bacterial-algal symbiotic systems can also be coupled with CO_2 fixation, and the combination of high CO_2 concentration in industrial flue gas for microalgae cultivation can simultaneously achieve carbon reduction and reduce the energy consumption of additional aeration of microalgae to supplement CO_2, which is in line with the development needs of "carbon neutral" . This article presents a systematic introduction of the mechanism, interaction forms and influencing factors of bacterial-algal symbiotic system in wastewater treatment and resource recovery process, and a summary of the potential of bacterial-algal engineering in pollutant degradation, CO_2 fixation and recovery of microalgal biomass products. The study of nutrient exchange, information transfer and genetic adaptation between bacteria and algae reveales that the selection of suitable symbiotic bacteria and algae combination culture can effectively enhance the pollutant removal and CO_2 fixation efficiency in wastewater. The effect of symbiosis on the accumulation of biological components (protein, lipid, carbohydrate, etc.) of algae is enhanced and selective. The selection of algae species and corresponding symbiotic bacteria, the adjustment of inoculation ratio and culture conditions can improve the efficiency of industrial scale harvesting of microalgae and further processing of biofuel and medical health food products. Bacterial-algal symbiosis is coupled with wastewater treatment, CO_2 fixation and biomass energy recovery in one. This article presents a critical review of development and progress of wastewater treatment and resource recovery surrounding microalgae-bacteria consortia. The development of the synthetic multi-functional system based on the consortium facilitates building an integrated sewage treatment and resource recovery processing mode featuring in low-carbon, economical and sustainable.

ClO• plays a key role in the UV/chlorine process besides Cl•, Cl2• − , and •OH. In many experiments, ClO• proved to be the main reactant that destroyed the organic pollutants in advanced oxidation process. About 200 rate constants of ClO• reactions were collected from the literature, grouped together according to the chemical structure, and the molecular structure dependencies were evaluated. In most experiments, ClO• was produced by the photolytic reaction of HClO/ClO−. For a few compounds, the rate constants were determined by the absolute method, pulse radiolysis. Most values were obtained in steady-state experiments by competitive technique or by complex kinetic calculations after measuring the pollutant degradation in the UV/chlorine process. About 30% of the listed rate constant values were derived in quantum chemical or in structure-reactivity (QSAR) calculations. The values show at least six orders of magnitude variations with the molecular structure. Molecules having electron-rich parts, e.g., phenol/phenolate, amine, or sulfite group have high rate constants in the range of 108–109 mol−1 dm3 s−1. ClO• is inactive in reactions with saturated molecules, alcohols, or simple aromatic molecules. HIGHLIGHTS ClO• has high rate constants with molecules having electron-rich activated parts.; ClO• has low reactivity with saturated molecules, alcohols, and simple aromatics.; For most compounds, only one published value is available.; Values obtained in different laboratories show a large scatter.;

Metal-organic frameworks (MOFs) are an exciting new class of porous materials with great potential for photocatalytic applications in the environmental and energy sectors. MOFs provide significant advantages over more traditional materials when used as photocatalysts due to their high surface area, adaptable topologies, and functional ability. In this article, we summarize current developments in the use of MOFs as photocatalysts for a variety of applications, such as CO2 reduction, water splitting, pollutant degradation, and hydrogen production. We discuss the fundamental properties of MOFs that make them ideal for photocatalytic applications, as well as strategies for improving their performance. The opportunities and challenges presented by this rapidly expanding field are also highlighted. [ABSTRACT FROM AUTHOR]

Semiconductor driven artificial photocatalysis is the most sustainable technology towards addressing the growing energy and environmental pollution issues. In this context, alloyed quantum dots (QDs) are an emerging class of promising nanomaterials gathering tremendous attention in this area due to several beneficial features. Compared to other bulk semiconductors, alloyed QDs are cost-effective, stable, less-toxic with superior optoelectronic features, which significantly enhances their solar energy conversion efficiency. Herein, the present review summarizes the fundamentals of alloyed QDs, various synthesis techniques, and discusses optical as well as structural properties from data interpretation point of view taking suitably reported literature. Moreover, we have provided a comprehensive summary of recent state of art metal chalcogenides based alloyed QD systems towards H 2 evolution, CO 2 reduction, and pollutant degradation. Finally, the review discusses the associated challenges and future prospects of alloyed QDs with a special focus on preparation, property engineering, theoretical aspect, stability and other field application. Additionally, the overarching aim is to provide researchers an in-depth understanding in the field of alloyed QDs relating to synthesis, characterisation, and promotes their photocatalytic applications, and can foster as a manual to future researchers. [Display omitted] • Fundamentals of Alloyed QDs as photocatalysts. • Various synthetic strategies of Alloyed QDs. • Characterisation methods to detect structural and optical properties. • Alloyed QDs photocatalyst for H 2 evolution, CO 2 reduction, pollutant degradation. [ABSTRACT FROM AUTHOR]