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Two-dimensional (2D) materials have emerged as a frontier in materials science, offering unique properties due to their atomically thin nature. Among these materials, bismuthene stands out due to its exceptional optical, electronic, and catalytic characteristics. Bismuthene exhibits high charge carrier mobility, stability, and a tunable bandgap (0.3–1.0 eV), making it highly suitable for applications in transistors, spintronics, biomedicine, and photocatalysis. This work explores the so far reported synthesis methods for obtaining 2D bismuthene, including bottom-up approaches like chemical vapor deposition and molecular beam epitaxy, and top-down methods such as liquid-phase exfoliation and mechanical exfoliation. Recent advancements in understanding 2D bismuthene structural phases, electronic properties modulated by spin-orbit coupling, and its potential applications in next-generation photocatalysts are also reviewed. As is retrieved by our literature review, 2D bismuthene shows great promise for addressing significant environmental challenges. For instance, in CO2 reduction, integrating bismuthene into 2D/2D heterostructures enhances electron transfer efficiency, thereby improving selectivity toward valuable products, such as CH4 and formic acid. In organic pollutant degradation, bismuth subcarbonate (Bi2O2CO3) nanosheets, obtained from 2D bismuthene, have demonstrated high photocatalytic degradation of antibiotics under visible light irradiation, due to their increased surface area and efficient generation of reactive species. Moreover, bismuthene-based materials exhibit potential in the photocatalytic water-splitting process for hydrogen production, overcoming issues associated with UV-light dependence and sacrificial agent usage. This review underscores the versatile applications of 2D bismuthene in advancing photocatalytic technologies, offering insights into future research directions and potential industrial applications.

In this study, we pioneered the synthesis of nanoflower-shaped TiO2-supported Au photocatalysts and investigated their properties. Au nanoflowers (Au NFs) were prepared by a Na-citrate and hydroquinone-based preparation method, followed by wet impregnation of the derived Au NFs on the surface of TiO2 nanorods (TNR). A uniform and homogeneous distribution of Au NFs was observed in the TNR + NF(0.7) sample (lower Na-citrate concentration), while their distribution was heterogeneous in the TNR + NF(1.4) sample (higher Na-citrate concentration). The UV-Vis DR spectra revealed the size- and shape-dependent optical properties of the Au NFs, with the LSPR effect observed in the visible region. The solid-state EPR spectra showed the presence of Ti3+, oxygen vacancies and electron interactions with organic compounds on the catalyst surface. In the case of the TNR + NF(0.7) sample, high photocatalytic activity was observed in the H2-assisted reduction of NO2 to N2 at room temperature under visible-light illumination. In contrast, the TNR + NF(1.4) catalyst as well as the heat-treated samples showed no ability to reduce NO2 under visible light, indicating the presence of deformed Au NFs limiting the LSPR effect. These results emphasized the importance of the choice of synthesis method, as this could strongly influence the photocatalytic activity of the Au NFs.

Emerging pollutants in wastewater pose significant risks to human health and wildlife, particularly due to their persistence in treated effluents from WWTPs. Very recent research has focused on developing new techniques based on advanced oxidation processes using inorganic and organic photocatalysts for treating polluted effluents under visible light. This study investigates a pesticide-removal system utilizing heterogeneous photoactive polymeric materials P2, P3, and P4. These materials, engineered as hydrophilic polymeric microparticles and functionalized with Rose Bengal, have demonstrated efficient singlet oxygen generation and first-order kinetics in the degradation of AHMPD, a pyrimidine fungicide. Given that most studies in the literature have concentrated on urban WWTPs, with less emphasis on industrial wastewater treatment, this research focused on real water samples from the effluent of an industrial WWTP in the agri-food sector, which processes large volumes of citrus and where high concentrations of AHMPD and other pesticides were detected at certain times of the year. The degradation potential of photoactive materials P3 and P4 was evaluated, achieving removal rates of AHMPD up to 85% under conditions of pH = 11 with 48 h of exposure to visible light.

In recent decades, numerous studies have indicated the substantial role semiconductors could play in photocatalytic processes for environmental applications. Materials that contain a semiconductor as a photocatalyst have a semi-permanent capacity for removing harmful gases from the ambient air. In this paper, the focus is on TiO2. Heterogeneous photocatalysis using TiO2 leads to the degradation of NO/NO2, benzene, toluene, and other priority air pollutants once in contact with the semiconductor surface. Preliminary evidence indicates that TiO2-containing construction materials and paints efficiently destroy the ozone precursors NO and NO2 by up to 80% and 30%, respectively. Therefore, the development of innovative coatings containing TiO2 as a photocatalyst was in the foreground of research activities. The aim of this was for coatings to be used as building and construction materials, mainly outdoors, e.g., on building façades on high-traffic roads for the degradation of priority air pollutants (NOx and volatile organic compounds) in the polluted urban atmosphere. Though there are advantages connected with the application of TiO2, due to its band gap of 3.2 eV, these are limited. TiO2 is effective only in the UV region (ca. 5%) of the solar spectrum with wavelengths λ < 380 nm. Hence, efforts are made here, as in many research studies, to dope TiO2 with transition metals to increase its activity using visible light, which will extend its application to indoor environments. In our studies, experiments were conducted with 0.1% (w/w) and 1% (w/w) Mn-TiO2 admixtures, and the ability of the modified photocatalysts to degrade NO by both solar and indoor illumination was evaluated. The surface chemistry at the air/catalyst interface, governed by the photoelectric characteristics of TiO2 and the formation of reactive oxygen species with co-occurring redox reactions, is reviewed in this paper. The factors affecting the application of TiO2 for the degradation of priority air pollutants as single compounds or mixtures are discussed. We investigated, particularly, the degradation of mixtures of priority compounds at typical concentrations in ambient air and confined spaces. This is a realistic approach, because pollutants are present as mixtures, rather than as individual compounds in ambient and indoor air. Moreover, organic polymers as paint constituents were found to be the primary source for carbonyl formation, e.g., formaldehyde, acetaldehyde, etc., during the heterogeneous photocatalytic processes conducted on TiO2-enriched coatings.

Advanced oxidation processes such as TiO2/UV heterogeneous photocatalysis are suitable treatment methods for wastewater with high pollutant loads such as landfill leachates. Optimizing the variables that influence the process is a fundamental aspect. However, in this regard, experimental conditions are limited in terms of resources and time, which is why modeling allows obtaining a general understanding of the phenomenon from a set of experimental data. This work sought to model the photocatalytic process via multivariate polynomial regression, considering variables such as the catalyst concentration, the pH level, and the accumulated energy concerning the percentage of degradation in terms of dissolved organic carbon (DOC). The implemented fitting method resulted in a third-degree polynomial with an R2 of 0,8652, concluding that the model and its conclusions are valid. Moreover, with greater degrees, the model curve overfitted, even with better R2. DOC abatement showed a negative correlation with pH and the catalyst dose, while an opposite trend was observed for the accumulated energy. The model predictions allow inferring that, at low catalyst doses and medium and high pH levels, it is possible to find maximum degradations at low cumulative energies.

Highly porous metal oxide–polymer nanocomposites are attracting considerable interest due to their unique structural and functional features. A porous polymer matrix brings properties such as high porosity and permeability, while the metal oxide phase adds functionality. For the metal oxide phase to perform its function, it must be fully accessible, and this is possible only at the pore surface, but functioning surfaces require controlled engineering, which remains a challenge. Here, highly porous nanocomposite beads based on thin metal oxide nanocoatings and polymerized high internal phase emulsions (polyHIPEs) are demonstrated. By leveraging the unique properties of polyHIPEs, i.e., a three-dimensional (3D) interconnected network of macropores, and high-precision of the atomic-layer-deposition technique (ALD), we were able to homogeneously coat the entire surface of the pores in polyHIPE beads with TiO2-, ZnO-, and Al2O3-based nanocoatings. Parameters such as nanocoating thickness, growth per cycle (GPC), and metal oxide (MO) composition were systematically controlled by varying the number of deposition cycles and dosing time under specific process conditions. The combination of polyHIPE structure and ALD technique proved advantageous, as MO-nanocoatings with thicknesses between 11 ± 3 and 40 ± 9 nm for TiO2 or 31 ± 6 and 74 ± 28 nm for ZnO and Al2O3, respectively, were successfully fabricated. It has been shown that the number of ALD cycles affects both the thickness and crystallinity of the MO nanocoatings. Finally, the potential of ALD-derived TiO2-polyHIPE beads in photocatalytic oxidation of an aqueous bisphenol A (BPA) solution was demonstrated. The beads exhibited about five times higher activity than nanocomposite beads prepared by the conventional (Pickering) method. Such ALD-derived polyHIPE nanocomposites could find wide application in nanotechnology, sensor development, or catalysis. [ABSTRACT FROM AUTHOR]

Porphyrin‐based porous organic polymers (Por‐POPs) are attracting increasing attention because of their potential in visible light photocatalysis. The distinctive attributes of Por‐POPs have been elucidated by investigating their response to specific reactions, such as the aerobic oxidation of sulfides. However, most researchers choose porphyrin molecules with relatively short peripheral substituent chains and strong stiffness to construct porphyrin‐based materials, especially Por‐POPS. Herein, we designed and prepared a flexible POP material H2Pp‐TAPM by incorporating extra π‐conjugated rigid units TAPM into a relatively flexible porphyrin monomer H2Pp through imine linkages. The POP synthesized in this study has demonstrated the ability to facilitate the transfer and dissociation of photogenerated electron–hole pairs, leading to the production of singlet oxygen 1O2 and superoxide radical anions O2˙−. These anions act as effective mediators for the selective aerobic oxidation of sulfides, resulting in the conversion of 99% and the selectivity more than 99%. Furthermore, the H2Pp‐TAPM has excellent stability and recyclability, indicating its attractiveness as heterogeneous photocatalyst for the transformation of organic compounds. This makes it a promising candidate for visible‐light‐driven reactions. [ABSTRACT FROM AUTHOR]

In recent years, due to the high consumption of drugs both for human needs and for their growing use, especially as regards antibiotics, in the diet of livestock, water pollution has reached very high levels and attracted widespread attention. Drugs have a stable chemical structure and are recalcitrant to many treatments, especially biological ones. Among the methods that have shown high efficiency are advanced oxidation processes (AOPs) which are, among other things, inexpensive and eco-friendly. AOPs are based on the production of reactive oxygen species (ROS) able to degrade organic pollutants in wastewater. The main problem related to the degradation of drugs is their partial oxidation to compounds that are often more harmful than their precursors. In this review, which is not intended to be exhaustive, we provide an overview of recent advances in the removal of organic drugs via advanced oxidation processes (AOPs). The salient points of each process, highlighting advantages and disadvantages, have been summarized. In particular, the use of AOPs such as UV, ozone, Fenton-based AOPs and heterogeneous photocatalysis in the removal of some of the most common drugs (tetracycline, ibuprofen, oxytetracycline, lincomycin) has been reported. [ABSTRACT FROM AUTHOR]

Carbon‐carbon (C−C) coupling of organic halides has been successfully achieved in homogeneous catalysis, while the limitation, e.g., the dependence on rare noble metals, complexity of the metal‐ligand catalylst and the poor catalyst stability and recyclability, needs to be tackled for a green process. The past few years have witnessed heterogeneous photocatalysis as a green and novel method for organic synthesis processes. However, the study on C−C coupling of chloride substrates is rare due to the extremely high bond energy of C−Cl bond (327 kJ mol−1). Here, we report a robust heterogeneous photocatalyst (Cu/ZnO) to drive the homo‐coupling of benzyl chloride with high efficiency, which achieves an unprecedented high selectivity of bibenzyl (93 %) and yield rate of 92 % at room temperature. Moreover, this photocatalytic process has been validated for C−C coupling of 10 benzylic chlorides all with high yields. In addition, the excellent stability has been observed for 8 cycles of reactions. With detailed characterization and DFT calculation, the high selectivity is attributed to the enhanced adsorption of reactants, stabilization of intermediates (benzyl radicals) for the selective coupling by the Cu loading and the moderate oxidation ability of the ZnO support, besides the promoted charge separation and transfer by Cu species. [ABSTRACT FROM AUTHOR]

The present study demonstrates the synthesis and application of Ag/ZnO powder films (thickness of 4 μm) as photocatalysts for natural sunlight and ultraviolet (UV, 315–400 nm) irradiation. The synthesis procedure is simple and eco-friendly, based on the photo-fixation of silver ions onto commercial ZnO powder via UV illumination for the first time. The photocatalytic efficiency of the newly developed films is evaluated through degradation of paracetamol in distilled and drinking water. Our experimental evidences show that the Ag/ZnO nanostructure films are more active than pristine ZnO films in the photodegradation process. Namely, the photocatalytic efficiency of the films modified with 10−2 M concentration of silver ions achieve the highest degradation (D) percentages for paracetamol in both types of water (Ddistilled = 80.97%, Ddrinking = 82.5%) under natural sunlight. Under UV exposure, the degradation percentages are slightly lower but still higher than those achieved by pure ZnO films (Ddistilled = 53.13%, Ddrinking = 61.87%). It is found that the photocatalytic activity grows in direct proportion to the concentration of Ag+ ions: ZnO < Ag 10−4/ZnO < Ag 10−3/ZnO < Ag 10−2/ZnO. Scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, UV–vis diffuse reflectance and photoluminescence spectroscopy are used to characterize the as-prepared ZnO and Ag/ZnO nanostructures. The improved photocatalytic performance of the Ag/ZnO films is mostly attributed to the combination of excited electron transfer from ZnO to Ag and the inhibition of photogenerated electron–hole pair recombination. Furthermore, Ag/ZnO nanostructure films can retain their photocatalytic activity after three cycles of use, highlighting their potential practical application for the treatment of pharmaceutical wastewater in real-world scenarios where natural sunlight is often more readily available than artificial UV light. [ABSTRACT FROM AUTHOR]

One of the main drawbacks of the application of photocatalysis for wastewater treatment is the use of dispersed photocatalysts, which are difficult to remove from effluent after the treatment process and may pose additional toxicity to the receiving bodies. As an alternative, immobilized catalysts can be applied; however, this strategy can increase the difficulties in mass and photo transfer. This work presents the development of an inert and highly porous support for TiO2 immobilization. The produced materials have a high surface area and contribute to diminishing the difficulties in mass and phototransfer during photocatalysis. Different types of polymeric materials were tested as support, and a Taguchi experimental design with an L9 arrangement was used to optimize the immobilization process and evaluate the effect of TiO2 content and the use of bidding agents, ultrasound, and thermic treatment. The grey automotive polyurethane foam proved to be the best support, using 5.0% of TiO2 (wt.%) in the immobilization suspension with Triton X as the binding agent and heat treatment during immobilization. At the optimal conditions, it was possible to achieve total As(III) oxidation (below the analytical detection limit) in 240 min, with nearly 100% As(V) present in solution at the end of the reaction (almost no As adsorption on the catalyst surface). In addition, the catalytic bed was able to promote the As(III) complete oxidation in up to five consecutive cycles without significant leaching or deactivation of the immobilized TiO2. [ABSTRACT FROM AUTHOR]

[Display omitted] • Cyano-modified graphitic carbon nitride (g-NCNCN x) was developed for photocatalytic perfluoroalkylation reactions.. • Photocatalytic addition or coupling reaction can be achieved selectively and effectively with a broad substrate scope. • g-NCNCN x exhibits excellent photocatalytic activity for at least five catalytic cycles. • More photoelectrons of g-NCNCN x generated after light irradiation, improving the photocatalytic performance, comparing to pristine g-CN x. Photocatalytic radical fluoroalkylation has become an important approach to prepare valuable organofluorine compounds under mild conditions. Compared to the homogenous photocatalytic fluoroalkylation reactions based on the precious metal complexes or organic dyes, heterogeneous photocatalysis using metal-free carbon nitride catalyst shows cost-effective, easier separation and excellent recyclability. In this work, we report the visible-light-induced photocatalytic perfluoroalkylation of alkynes with perfluoroalkyl iodides (R f I) using heterogeneous cyano-modified graphitic carbon nitride (g-NCNCNx) as the photocatalyst. The mechanism proposed by the experimental and computational studies reveals that the long-lived triplet excited states in photoinduced g-NCNCNx are involved in the initial bimolecular electron transfer process, resulting in the effective activation of R f I and the improvement of sequential photocatalytic reactions. Moreover, the stronger interaction between the substate and surface of catalyst g-NCNCNx can further improve the photocatalytic activity, comparing to the pristine carbon nitride (g-CNx). Through simple variation of the reaction conditions, the photocatalytic addition or coupling reaction can be achieved effectively and selectively. Importantly, the heterogeneous g-NCNCNx photocatalyst can not only show high performance with a wide reaction scope, but also be readily recovered and reused for at least five catalytic cycles with high photocatalytic activity. This work provides a sustainable alternative to the conventional metal-based photocatalysts for organofluorine synthesis. [ABSTRACT FROM AUTHOR]

[Display omitted] • Mass transfer-based heterogeneous photocatalysis for efficient energy transport. • Direct one-pot immobilization of iridium (III) complex via covalent linkage. • Fast mass transfer of reactants in hollow porous polystyrene nanospheres. • Crosslinking degree-dependent optical properties of anchored fac -Ir(ppy) 3. • Comparable catalytic activity to homogeneous fac -Ir(ppy) 3. Heterogeneous photocatalysis of iridium (III) complexes faces two major bottle-necks: limited mass/energy transfer and tedious immobilization. In this work, fac -Ir(ppy) 3 is directly anchored to hollow mesoporous polystyrene nanospheres (HMPNs) via one-pot F-C alkylation, achieving the covalent immobilization of fac -Ir(ppy) 3 at a low-cost. The thin shell, pores, hollow interior, and swelling property of HMPNs enable reactants to quickly access to fac -Ir(ppy) 3 , effectively avoiding energy loss in energy transport from excited fac -Ir(ppy) 3 * to reactants. The mass transfer of reactants and optical properties of fac -Ir(ppy) 3 such as quantum yield, luminescent lifetime and band gap energy closely depend on the cross-linking degree of polystyrene. The anchored fac -Ir(ppy) 3 exhibits comparable catalytic activity to homogeneous fac -Ir(ppy) 3 in heterogeneous [2 + 2] photodimerization of olefins with a good reusability without a significant decrease in yields over ten recycles. This work develops a strategy for fabricating efficient heterogeneous photocatalysts using available non-conjugated polymer as support based on the concept of fast mass transfer of reactants. [ABSTRACT FROM AUTHOR]

TiO2 is one of the most promising heterogeneous photoredox catalysts employed in oxidative pollutant destruction, CO2 reduction, water splitting, disinfection, solar cell design and organic synthesis. Due to the wide bandgap of TiO2, visible light energy is not sufficient for its activation, and electron/hole pairs generated upon UV irradiation demonstrate limited selectivity for application in organic synthesis. Thus, the development of TiO2-based catalytic systems activated by visible light is highly attractive. In the present work we demonstrate the generation of t-BuOO• radicals from tert-butylhydroperoxide catalyzed using commercially available unmodified TiO2 under visible light. This finding was used for the highly selective CH-peroxidation of barbituric acids, which contrasts with the behavior of the known TiO2/H2O2/UV photocatalytic system used for deep oxidation of organic pollutants. [ABSTRACT FROM AUTHOR]

Ciprofloxacin (CIP) is a frequently prescribed antibiotic for various medicinal purposes that have been detected in surface water, wastewater, and wastewater treatment plants. It is a persistent organic pollutant due to its halogenated heterocyclic structure and high chemical stability at a wide range of pH. The presence of CIP in wastewater treatment plants is an indication that the antibiotic could not be removed via conventional methods. Recently, various researchers have reported the successful elimination of CIP from polluted water via photocatalytic degradation. The degradation efficacy of a photocatalyst is in direct relation to the choice of the photocatalyst and the experimental conditions employed. This review elaborates on the available literature on the photocatalytic degradation of CIP and the role of various operational parameters including photocatalyst type, modification and dosage, initial substrate concentration, pH of the reaction medium, and ionic components on the photocatalytic degradation of CIP in aqueous media. The obtained results revealed that better degradation results are recorded using various catalysts at acidic pH values, and up to 100% degradation efficiency can be achieved with catalyst modification. [ABSTRACT FROM AUTHOR]

Advanced oxidation processes, including photocatalysis, have been proven effective at organic dye degradation. Tailored porous materials with regulated pore size, shape, and morphology offer a sustainable solution to the water pollution problem by acting as support materials to grafted photocatalytic nanoparticles (NPs). This research investigated the influence of pore and particle sizes of photocatalytic MICROSCAFS® on the degradation of methyl orange (MO) in aqueous solution (10 mg/L). Photocatalytic MICROSCAFS® are made of binder-less supported P25 TiO2 NPs within MICROSCAFS®, which are silica–titania microspheres with a controlled size and interconnected macroporosity, synthesized by an adapted sol–gel method that involves a polymerization-induced phase separation process. Photocatalytic experiments were performed both in batch and flow reactors, with this latter one targeting a proof of concept for continuous transformation processes and real-life conditions. Photocatalytic degradation of 87% in 2 h (batch) was achieved, using a calibrated solar light simulator (1 sun) and a photocatalyst/pollutant mass ratio of 23. This study introduces a novel flow kinetic model which provides the modeling and simulation of the photocatalytic MICROSCAFS® performance. A scavenger study was performed, enabling an in-depth mechanistic understanding. Finally, the transformation products resulting from the MO photocatalytic degradation were elucidated by high-resolution mass spectrometry experiments and subjected to an in silico toxicity assessment.

Prions are proteinaceous pathogens responsible for a variety of devastating diseases in mammals, including scrapie in sheep and goats, chronic wasting disease in cervids, and Creutzfeldt–Jakob disease (CJD) in humans. They are characterized by their exceptional persistence to common inactivation procedures. This applies to all possible sources of prion contamination as prions may be present in the tissues and biological fluids of infected individuals. Hence, efficient prion inactivation procedures are still being sought to minimize the risk of intra- or inter-species transmission. In the past, photocatalytic treatment has been proven to be capable of efficiently oxidizing and inactivating prions. In the present study, the efficacy of homogeneous photo-Fenton-based photocatalysis as well as heterogeneous photocatalysis with TiO2 in reducing RML mouse scrapie infectivity was evaluated. Prion inactivation was assessed by means of a bioassay, and the results were confirmed by in vitro experiments. While the prion infectivity of the RML mouse scrapie was reduced after treatment with the photo-Fenton reagent, the heterogeneous photocatalytic treatment of the same prion strain completely eliminated prion infectivity.

In the herein report, we synthesized ZnO thin films doped with manganese (Mn). We studied the impact of Mn doping loads (1 %, 3 %, 5 % wt.) on physicochemical properties of the compounds. Furthermore, we presented the photocatalytic efficiency in removal of methylene blue dye. The structural assay indicated ZnO conserve the wurtzite crystalline structure after dopant insertion. Furthermore, the crystalline size of catalysts was reduced after dopant incorporation. The SEM analysis showed a change in surface morphology after modification of ZnO thin films. Furthermore, Raman spectroscopy verified the Mn insertion inside the ZnO lattice. After the doping process, band gap was reduced by 16 %, in comparison to bare ZnO. After the photocatalytic test, the doped catalysts showed better performance than bare ZnO in removing MB. The best test showed a kinetics constant value of 2.9 × 10−3 min−1 after 120 min of visible irradiation. Finally, the Mn(5 %):ZnO thin film was suitable after five degradation cycles, and the degradation process efficiency was reduced by 32%.

The NixCu(1-x)Fe2O4 (x = 0, 0.2, 0.8, 1) mixed nickel and copper ferrites were synthesized using the EDTA-Citrate complexation method and calcined at 700°C. The structure, properties and characterization of the samples were analyzed by DRX, Rietveld refinement, SEM, and DRE UV-Vis, indicating the phase formation of tetragonal (CuFe2O4 and Ni0.2Cu0.8Fe2O4) and cubic (Ni0.8Cu0.2Fe2O4 and NiFe2O4). The materials exhibited morphologies suitable for photocatalytic applications and a UV-Vis absorption range near 2 eV as expected for spinel ferrites. These materials were evaluated as photocatalysts for the degradation of Rhodamine B dye under heterogeneous photocatalysis conditions, simulating solar light irradiation, air injection, and different pH levels (2, 6, and 10). The results showed that the catalytic efficiency was higher for samples with a higher copper content and in a basic medium. Therefore, NixCu(1-x)Fe2O4 mixed ferrites have promising potential as photocatalysts.

Reactions between a gas phase and a solid material are of high importance in the study of alternative ways for energy conversion utilizing otherwise useless carbon dioxide (CO2). The photocatalytic CO2 reduction to hydrocarbon fuels like e.g., methane (CH4) is such a potential candidate process converting solar light into molecular bonds. In this work, the design, construction, and operation of a high-purity gas–solid photoreactor is described. The design aims at eliminating any unwanted carbon-containing impurities and leak points, ensuring the collection of reliable and reproducible data in photocatalytic CO2 reduction measurements. Apart from the hardware design, a detailed experimental procedure including gas analysis is presented, allowing newcomers in the field of gas–solid CO2 reduction to learn the essential basics and valuable tricks. By performing extensive blank measurements (with/without sample and/or light) the true performance of photocatalytic materials can be monitored, leading to the identification of trends and the proposal of possible mechanisms in CO2 photoreduction. The reproducibility of measurements between different versions of the here presented reactor on the ppm level is evidenced.

In this study, heterostructured g-C3N4/Ag–TiO2 nanocomposites were successfully fabricated using an easily accessible hydrothermal route. Various analytical tools were employed to investigate the surface morphology, crystal structure, specific surface area, and optical properties of as-synthesized samples. XRD and TEM characterization results provided evidence of the successful fabrication of the ternary g-C3N4/Ag–TiO2 heterostructured nanocomposite. The heterostructured g-C3N4/Ag–TiO2 nanocomposite exhibited the best degradation efficiency of 98.04% against rhodamine B (RhB) within 180 min under visible LED light irradiation. The g-C3N4/Ag–TiO2 nanocomposite exhibited an apparent reaction rate constant 13.16, 4.7, and 1.33 times higher than that of TiO2, Ag–TiO2, and g-C3N4, respectively. The g-C3N4/Ag–TiO2 ternary composite demonstrated higher photocatalytic activity than pristine TiO2 and binary Ag–TiO2 photocatalysts for the degradation of RhB under visible LED light irradiation. The improved photocatalytic performance of the g-C3N4/Ag–TiO2 nanocomposite can be attributed to the formation of an excellent heterostructure between TiO2 and g-C3N4 as well as the incorporation of Ag nanoparticles, which promoted efficient charge carrier separation and transfer and suppressed the rate of recombination. Therefore, this study presents the development of heterostructured g-C3N4/Ag–TiO2 nanocomposites that exhibit excellent photocatalytic performance for the efficient degradation of harmful organic pollutants in wastewater, making them promising candidates for environmental remediation. [ABSTRACT FROM AUTHOR]

Photocatalytic membrane reactors (PMRs) have been found to be very effective in the removal of organic pollutants (particularly recalcitrant compounds) from wastewater because they allow for the mineralization of organic pollutants to innocuous by-products, thus achieving high-quality treated water. Owing to the very high volumes of water involved, treated sewage wastewater could be reused if a very efficient tertiary stage, like a PMR, can be foreseen. In this review, the two main PMR configurations (photocatalytic membranes and slurry PMRs) were analyzed as requirements of a tertiary treatment of sewage wastewater considering six design and operational parameters of such plants: (i) continuous wastewater flow rate from the secondary stage; (ii) the self-control of the photodegradation rate related to wastewater chemical–physical parameters; (iii) ability to handle variations of wastewater concentration and flow rate; (iv) the control of the quality of treated wastewater; (v) low plant footprint; and (vi) easy maintenance. In this analysis, some characteristics of photocatalysis (which involves three phases: solid (the photocatalyst), liquid (the wastewater), and gas (oxygen or air)) and those of membranes (they can be produced using different materials and configurations, different processes (pressure-driven or not pressure-driven), etc.) were considered. The obtained results show that slurry PMRs seem more suitable than photocatalytic membranes for such applications. We believe this review can trigger a shift in research from the laboratory to industry in using photocatalytic membrane reactors. [ABSTRACT FROM AUTHOR]

The improper disposal of toxic and carcinogenic organic substances resulting from the manufacture of dyes, drugs and pesticides can contaminate aquatic environments and potable water resources and cause serious damage to animal and human health and to the ecosystem. In this sense, heterogeneous photocatalysis stand out as one effective and cost-effective water depollution technique. The use of metal oxide nanocomposites (MON), from the mixture of two or more oxides or between these oxides and other functional semiconductor materials, have gained increasing attention from researchers and industrial developers as a potential alternative to produce efficient and environmentally friendly photocatalysts for the remediation of water contamination by organic compounds. Thus, this work presents an updated review of the main advances in the use of metal oxide nanocomposites-based photocatalysts for decontamination of water polluted by these substances. A bibliometric analysis allowed to show the evolution of the importance of this research topic in the literature over the last decade. The results of the study also showed that hierarchical and heterogeneous nanostructures of metal oxides, as well as conducting polymers and carbon materials, currently stand out as the main materials for the synthesis of MON, with better photocatalysis performance in the degradation of dyes, pharmaceuticals and pesticides. [ABSTRACT FROM AUTHOR]

BACKGROUND: Heterogeneous photocatalysis offers an interesting alternative to mitigate air pollution by using materials capable of reacting with toxic gases under ultraviolet light. One of these materials is titanium dioxide (TiO2), and thus it is necessary to analyze and improve its photocatalytic response for air depollution, in order to facilitate its use in surface applications. RESULTS: The photocatalytic ability of the synthesized TiO2 particles to remove nitric oxide (NO) was tested, and it was found that both the anatase and rutile phases present in the samples led to a NO abatement capacity of ≈60% η NO. Two different methods to coat surfaces with TiO2 particles were evaluated: thermal spray by oxyacetylene flame and dripping of polymeric suspensions of TiO2. A more detrimental effect on photocatalytic efficiencies was found using polymeric suspension rather than flame‐spraying as coating method. This was despite the anatase transformation to rutile and Ti7O13 that TiO2 particles undergo using the latter process as a consequence of heat transfer from the flame to the particles during the coating formation. CONCLUSION: Results obtained in this research demonstrate that polymeric suspensions inhibit the photocatalytic activity of TiO2 nanoparticles, probably due to the formation of a polymeric matrix on samples that constrains the action of pollutant and testing factors on samples. However, the thermal method can help retain part of the photocatalytic capability to abate NOx, despite depletion in the anatase content resulting from the heat transfer to the TiO2 raw particles sprayed to form coatings. © 2023 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

The transformation of recalcitrant pharmaceutical pollutants into products with diminished concerns via heterogeneous photocatalysis has gained considerable momentum over the past several years. However, practical applications of most semiconductor-based photocatalysts are severely restricted, attributed to insufficient visible light response pertaining to their wide band gap, ultrafast recombination of the photogenerated charge carriers, and issues corresponding to retrieval for persistent usage. Herein, rosette-like molybdenum disulfide (MoS2) nanoflowers are directly grown on the interpenetrating networks of graphene aerogels (GAs) through a facile one-step hydrothermal method, and the resulting lightweight, self-supporting composites are systematically assessed for the photocatalytic degradation of tetracycline (TC). Notably, after 120 min of exposure to visible light, ∼91% of TC is degraded over the MoS2/GAs, which is severalfold higher than pristine MoS2, standalone GA, and other contemporary photocatalysts. Based on the radical quenching assay, hydroxyl radicals and superoxide anions are the principal mediators of the photocatalytic dissociation of TC. Furthermore, the primary intermediates and residual products of the photocatalytic breakdown of TC are distinguished, and a conceivable disintegration pathway is proposed. Besides, these tailor-made hybrid aerogels can be recuperated easily and successfully reused over multiple cycles, suggesting their widespread consideration in photocatalytic wastewater treatment. [ABSTRACT FROM AUTHOR]

Certain metal complexes are known as high‐performance CO2 reduction photocatalysts driven by visible light. However, most of them rely on rare, precious metals as principal components, and integrating the functions of light absorption and catalysis into a single molecular unit based on abundant metals remains a challenge. Metal‐organic frameworks (MOFs), which can be regarded as intermediate compounds between molecules and inorganic solids, are potential platforms for the construction of a simple photocatalytic system composed only of Earth‐abundant nontoxic elements. In this work, we report that a tin‐based MOF enables the conversion of CO2 into formic acid with a record high apparent quantum yield (9.8 % at 400 nm) and >99 % selectivity without the need for any additional photosensitizer or catalyst. This work highlights a new MOF with strong potential for photocatalytic CO2 reduction driven by solar energy. [ABSTRACT FROM AUTHOR]

It is well-documented that accumulation of pharmaceutically active compounds (PhACs), such as antibiotics, in aquatic ecosystems is a prominent environmental hazard. Herein, a series of 2D materials–based heterojunctions, conceptualized based on the integration of graphitic carbon nitride (g-C3N4) with tungsten disulfide (WS2), was fabricated through a facile one-step calcination process, and systematically evaluated for eliminating tetracycline (TC) and sulfamethoxazole (SMX) from aqueous matrices. The microstructure, optical properties, and surface chemistry of the as-prepared composites were examined with a range of microscopy and spectroscopy techniques. In comparison with pristine g-C3N4 or bare WS2, the g-C3N4/WS2 material, with optimal WS2 loading, showed significantly improved photocatalytic activity, towards degradation of TC (84%) and SMX (96%), under visible light. Free radical scavenging experiments revealed that superoxide anions and hydroxyl radicals were predominantly responsible for the rapid breakdown of the PhACs. In addition, the dissociation intermediates and residues were identified and the plausible photocatalytic degradation pathways of TC and SMX over the as-constructed 2D/2D heterojunction were discussed. Further, the photocatalysis end products were non-toxic, as inferred via the resazurin cell viability assay, employing Escherichia coli as a model organism. Most importantly, the 2D/2D g-C3N4/WS2 architecture was structurally resilient and exhibited a fairly stable cycling performance for persistent usage in wastewater treatment. The outcomes of this study testify that 2D/2D heterojunction of g-C3N4 fragments and WS2 nanosheets holds great promise for destroying antibiotics or their metabolites, usually present in wastewaters. [ABSTRACT FROM AUTHOR]

Background: Heterogeneous photocatalysis has been considered one of the most attractive methods in the wastewater remediation process due to allowing continuous re‐use, the reactions taking place at room temperature, and photocatalysts are inexpensive. Objective: With the optimization of the structural properties of hematite at the nanometer level by utilizing engineering strategies such as morphology regulation, and shape control, it is possible to enhance its photocatalytic performance. The study's main objective is to improve photocatalytic performances of visible‐light photoactive hematite materials produced by engineering strategies. Methods: The α‐Fe2O3 photocatalyst fibres with highly porous were fabricated by electrospinning method, allowing extraordinary length, a large ratio of length to diameter, hierarchically porous structure, high surface area, small grain sizes, and high porosity. Results: In the heterogeneous photocatalysis of the electrospun α‐Fe2O3 nanofibers against two model dyes representing anionic (MO) and cationic (RhB) characteristics, both electrospun α‐Fe2O3 nanofibers showed good photocatalytic activity against used model pollutants. The α‐ α‐Fe2O3 nanofibers produced using iron(III) chloride hexahydrate exhibited a higher photocatalytic degradation rate against both dye pollutants relative to the α‐ α‐Fe2O3 nanofibers produced using iron(III) chloride. Conclusions: Depending on the used iron sources and associatively their final morphological characteristics, it was observed that their photocatalytic degradation performances were seriously affected. It is suggested that electrospun α‐Fe2O3 nanofibers, especially those with highly porous and smaller diameters, are suitable candidates as a visible‐light‐driven semiconductor material to use in advanced oxidation processes for removing pollutants from wastewater. [ABSTRACT FROM AUTHOR]

Although environmental and clean energy research has identified graphitic carbon nitride impregnated with reduced graphene oxide (rGO/g-C3N4) as a potential, efficient non-metallic photocatalyst, its efficacy against Contaminants of Emerging Concern (CECs) is relatively unknown. This study reports an optimized photocatalyst (response surface methodology, RSM) to remove the plasticizer and endocrine disruptor bisphenol A (BPA) from water. The synthetic procedure included sonication of prepared particles of g-C3N4 and graphite oxide (rGO), followed by reduction with hydrazine (24 h reflux), increasing specific surface areas, and improving synthesis reproducibility. In optimal conditions, the produced photocatalyst (50 mg L–1) removed 90% of BPA (100 mL, 100 μg L−1) in 90 min (30 min in the dark + 60 min irradiated) using a UV source (centered at 365 nm, 26 W) and exhibiting pseudo-first-order kinetics. For comparison purposes, under the same experimental conditions, pure g-C3N4 removed 50% of the BPA solution. Radical scavenging tests identified the superoxide radical as the main reactive oxygen species involved in the degradation. Two major degradation products were identified by mass spectrometry, both of them less ecotoxic than BPA to a variety of test organisms, according to in silico estimations (ECOSAR 2.0). [ABSTRACT FROM AUTHOR]

Environmental concern about emerging contaminants has increased, especially endocrine-disrupting chemicals such as 17α-ethynylestradiol. Conventional water treatment processes have limitations in their removal, while heterogeneous photocatalysis is a promising technique. This requires the application of an efficient photocatalyst that is activated under visible light for a more sustainable process. Transition metals incorporated into TiO2 have shown great potential in improving visible light absorption and reducing recombination speed. Thus, the objective of this study was to prepare and characterize TiO2-based photocatalysts incorporated with Ag, Cu, and Fe and evaluate their performance in the removal of the hormone 17α-ethynylestradiol under visible light. The photocatalysts were prepared using the wet impregnation method and characterized by adequate techniques. The photocatalysts were activated under visible light from an automotive xenon light, and batch tests were made under the experimental conditions: [EE2]0 = 10 mg L−1 and catalyst dosage = 0.5 g L−1. The photocatalysts showed optical improvements, such as reduced bandgap energy and reduced recombination velocity. And they were efficient in the photodegradation of the hormone compared to TiO2. The toxicity of the effluent containing 17α-ethynylestradiol was reduced after the heterogeneous photocatalysis process, as shown in bioassays with the bioindicators Artemia salina and Lactuca sativa. [ABSTRACT FROM AUTHOR]

Due to inadequate treatment and incorrect management, wastewater with dyes has a great toxic potential as an environmental liability, representing a major concern. In this context, this work aims to investigate the potential application of nanostructured powdery systems (nanocapsules and liposomes) in the photodegradation of Rhodamine B (RhB) dye, under UV and visible irradiation. Curcumin nanocapsules and liposomes containing ascorbic acid and ascorbyl palmitate were prepared, characterized, and dried using the spray drying technique. The drying processes of the nanocapsule and the liposome showed yields of 88% and 62%, respectively, and, after aqueous resuspension of the dry powders, it was possible to recover the nanocapsule size (140 nm) and liposome size (160 nm). The dry powders were characterized by Fourier transform infrared spectroscopy (FTIR), N2 physisorption at 77 K, X-ray diffraction (XRD), and diffuse reflectance spectroscopy (DRS-UV). Under UV irradiation, 64.8% and 58.48% of RhB were removed with nanocapsules and liposomes, respectively. While under visible radiation, nanocapsules and liposomes were able to degrade 59.54% and 48.79% of RhB, respectively. Under the same conditions, commercial TiO2 showed degradation of 50.02% (UV) and 42.14% (visible). After 5 cycles of reuse, there was a decrease of about 5% for dry powders under UV irradiation and 7.5% under visible irradiation. Therefore, the nanostructured systems developed have potential application in heterogeneous photocatalysis for the degradation of organic pollutants, such as RhB, as they demonstrated superior photocatalytic performance to commercial catalysts (nanoencapsulated curcumin > ascorbic acid and ascorbyl palmitate liposomal > TiO2). [ABSTRACT FROM AUTHOR]

Heterogeneous photocatalysis is a promising approach for a wide range of hydrogenative reactions owing to the mild reaction conditions and the possibility of employing liquid hydrogen donors. Currently, the major interest is focused on the development of high performance photocatalyst materials and the expansion of reaction scope. An overview from a perspective of hydrogen donor and thus the related mechanistic understanding of the light‐induced hydrogenative reactions is rare. Here, we have categorized the photocatalytic hydrogenative reactions by the type of employed liquid hydrogen donors (hydrocarbons and water), discussed the basic criteria of hydrogen abstraction from these donors, and elaborated the design strategy of the photocatalyst materials. [ABSTRACT FROM AUTHOR]

Combining the strong localized surface plasmon resonance (LSPR) of metallic Ag and the chemically reactive Pt co-catalyst, the Ag–Pt bimetallic composite was prepared and then coated on the surface of the exfoliated defective graphitic carbon nitride nanosheets (C 3 N x NS) for plasmon hot electron-mediated photocatalytic H 2 evolution. Under the visible light irradiation, the sample of (1:2) Ag–Pt/C 3 N x NS exhibits the highest activity (1.25 mmol g−1 h−1), which is 35.7 and 1.7 times higher than that of Ag/C 3 N x NS and Pt/C 3 N x NS, respectively. Moreover, the apparent quantum efficiency (AQE) of (1:2) Ag–Pt/C 3 N x NS reaches 3.3% at 420 nm. The boosted photocatalytic capacity may be ascribed to the utilization of the advantages of the LSPR effect of Ag particles and the Schottky barrier between Pt and C 3 N x NS, resulting in more electrons participate in the reduction reaction to boost the photocatalytic H 2 evolution performance. [Display omitted] • Ag–Pt core-shell structure was deposited on the exfoliated defective C 3 N x nanosheets. • The Core Ag shows LSPR effect and the shell Pt acts chemically reactive co-catalyst. • The (1:2) Ag–Pt/C 3 N x NS exhibits the highest H 2 evolution rate (1.25 mmol g−1 h−1). • The AQE of the sample of (1:2) Ag–Pt/C 3 N x NS reaches 3.3% at 420 nm. • The boosted activity was attributed to the LSPR effect and the Schottky barrier. [ABSTRACT FROM AUTHOR]

Environmental‐friendly halogenation of C−H bonds using abundant, non‐toxic halogen salts is in high demand in various chemical industries, yet the efficiency and selectivity of laboratory available protocols are far behind the conventional photolytic halogenation process which uses hazardous halogen sources. Here we report an FeX2 (X=Br, Cl) coupled semiconductor system for efficient, selective, and continuous photocatalytic halogenation using NaX as halogen source under mild conditions. Herein, FeX2 catalyzes the reduction of molecular oxygen and the consumption of generated oxygen radicals, thus boosting the generation of halogen radicals and elemental halogen for direct halogenation and indirect halogenation via the formation of FeX3. Recycling of FeX2 and FeX3 during the photocatalytic process enables the halogenation of a wide range of hydrocarbons in a continuous flow, rendering it a promising method for applications. [ABSTRACT FROM AUTHOR]

Rational design of polymer structures at the molecular level promotes the iteration of high‐performance photocatalyst for sustainable photocatalytic hydrogen peroxide (H2O2) production from oxygen and water, which also lays the basis for revealing the reaction mechanism. Here we report a benzoxazine‐based m‐aminophenol‐formaldehyde resin (APFac) polymerized at ambient conditions, exhibiting superior H2O2 yield and long‐term stability to most polymeric photocatalysts. Benzoxazine structure was identified as the crucial photocatalytic active segment in APFac. Favorable adsorption of oxygen/intermediates on benzoxazine structure and commendable product selectivity accelerated the reaction kinetically in stepwise single‐electron oxygen reduction reaction. The proposed benzoxazine‐based phenolic resin provides the possibility of production in batches and industrial application, and sheds light on the de novo design and analysis of metal‐free polymeric photocatalysts. [ABSTRACT FROM AUTHOR]

Methotrexate (MTX) is a folic acid analog and has been used to treat a wide variety of malignant and non-malignant diseases. The wide use of these substances has led to the continuous discharge of the parent compound and its metabolites in wastewater. In conventional wastewater treatment plants, the removal or degradation of drugs is not complete. In order to study the MTX degradation by photolysis and photocatalysis processes, two reactors were used with TiO2 as a catalyst and UV-C lamps as a radiation source. H2O2 addition was also studied (absence and 3 mM/L), and different initial pHs (3.5, 7, and 9.5) were tested to define the best degradation parameters. Results were analyzed by means of ANOVA and the Tukey test. Results show that photolysis in acidic conditions with 3 mM of H2O2 added is the best condition for MTX degradation in these reactors, with a kinetic constant of 0.028 min−1. According to the ANOVA test, all considered factors (process, pH, H2O2 addition, and experimentation time) caused statistically significant differences in the MTX degradation results. [ABSTRACT FROM AUTHOR]

Photocatalysis has been oft proposed as a green solution for pollution remediation, however, majority of the existing literature only studies the degradation of solitary analytes. The degradation of mixtures of organic contaminants is inherently more complicated due to a variety of photochemical processes that occur in parallel. Here, we describe a model system comprised of methylene blue and methyl orange dyes whose degradation carried out by two common photocatalysts, P25 TiO2 and g-C3N4. With P25 TiO2 as the catalyst, the degradation rate of methyl orange slowed by 50% when degraded in a mixture compared to when alone. Control experiments with radical scavengers showed this to occur due to competition between the dyes for oxidative photogenerated species. In the presence of g-C3N4, methyl orange's degradation rate in the mixture increased by 2300% due to two homogeneous photocatalysis processes sensitized by methylene blue. Homogenous photocatalysis was found to be fast relative to heterogeneous photocatalysis by g-C3N4 but slow relative to photocatalysis by P25 TiO2 and explains the change observed between the two catalysts. Changes in dye adsorption to the catalyst when in a mixture were also explored but not found to coincide with changes in degradation rate. [ABSTRACT FROM AUTHOR]

The low cost, earth abundance, nontoxic, and efficient photocatalysts materials have a critical role in order to solve environmental issues. In this regard, hematite (α-Fe2O3) has received significant attention due to its desirable properties. In the present study, zinc-doped and copper-doped hematite nanoparticles were synthesized by the hydrothermal method. The photocatalytic features of produced nanopowders were investigated. The evaluations of photocatalytic activities of synthesized nanoparticles were executed by monitoring the degradation rate of Rhodamine B (RhB) under the solar simulator in heterogeneous photocatalysis. Compared to commercial Degussa TiO2 powder, the transition metal doped hematite (α-Fe2O3) samples showed better photocatalytic activities against RhB under the solar simulator. It was observed that even though there were no significant differences in their characteristic properties strongly affecting photocatalytic activity such as morphological features, optical absorption characteristics, and band gaps, Cu-doped α-Fe2O3 nanoparticles exhibited higher photocatalytic activity, which is %20 higher than the Zn-doped α-Fe2O3. The synthesized Cu-doped hematite nanoparticles are hopeful materials as a visible-light-driven photocatalytic material to degrade organic pollutants in aquatic media.

The main objective of this study was to investigate the photodegradation of azo dye Cibacron Brilliant Yellow 3G-P using Anatase, Degussa-P25 and ZnO. These semi-conductors were characterized using XRD, BET and TEM-EDX. The variation of the amount of semi-conductors significantly affect the rate of color removal. The decolorization rate increased as the catalyst dosage was increased. Other parameters were also studied, such as stirring speed, pH, and initial dye concentration. It was found that the rate of decolorization increases with the increase of stirring speed. Decolorization of about 30, 60 and 80% was respectively achieved in the case of Anatase, Degussa-P25 and ZnO at low stirring speed (50rpm). At pH = 3, the degradation rate was found to be higher than the alkaline pH, about 95.58 and 85.71% of color has been decolorized with Anatase and Degussa-P25 respectively. While using ZnO, the color removal reached maximum in acidic and alkaline solutions, more than 95% of dye was decolorized. The concentrations dye solutions less than 80ppm led to the removal rate of about 95% in the case of ZnO, while it was only about 8–15% in the case of TiO2 with the concentration more than 20 ppm. HIGHLIGHTS Decolourization and photocatalytic degradation of Cibacron Brilliant Yellow 3G-P under UV light radiation.; Anatase displayed higher photocatalytic efficiency than Degussa-P25 and ZnO.; The photocatalytic degradation efficiency of Anatase and Degussa-P25 was observed to be higher at pH = 3.;

In this era of globalization, plastic is regarded as one of the most versatile innovations, finding its uses ranging from packaging, automotive, agriculture, and construction to the medical and pharmaceutical industries. Unfortunately, the single-use nature of plastics leads to ecological and environmental problems. Among conventional disposal management of plastic waste are landfilling dumping, incineration, and recycling. However, not all plastic waste goes into disposal management and ends up accumulating in lakes, rivers, and seas. In the aquatic environment, the action of photochemical weathering plastics has resulted in the release of chemical additives such as phthalic acid esters (PAEs), an important plasticizer added to plastic products to improve their softness, flexibility, and durability. Nowadays, PAEs have been ubiquitously detected in our environment and numerous organisms are exposed to PAEs to some extent. As PAEs carry endocrine disruptive and carcinogenicity properties, an urgent search for the development of an efficient and effective method to remove PAEs from the environment is needed. As a viable option, titania (TiO2) photocatalysis is a promising tool to combat the PAEs contamination in our environment owing to its high photocatalytic activity, cost-effectiveness, and its ability to totally mineralize PAEs into carbon dioxide and water. Hence, this paper aims to highlight the concerning issue of the contamination of PAEs in our aquatic environments and the summary of the removal of PAEs by TiO2 photocatalysis. This review concerning the significance of knowledge on environmental PAEs would hopefully spark huge interest and future development to tackle this plastic-associated pollutant. Copyright © 2022 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Heterogeneous photocatalysis is effective for the selective synthesis of value‐added chemicals at lab‐scale, yet falls short of requirements for mass production (low cost and user friendliness). Here we report the design and fabrication of a modular tubular flow system embedded with replaceable photocatalyst membranes for scalable photocatalytic C−C, C−N homocoupling and hydrogenation reactions, which can be operated in either circular and continuous flow mode with high performance. The photocatalyst membranes almost fully occupy the volume of the reactor, thus enabling optimal absorption of the incident light. Additionally, the porous structured photocatalyst membranes facilitate the mass transfer of the reactants to efficiently use the active sites, resulting in 0th‐order reaction kinetics and a high space‐time yield compared to the batch reaction system at practical application levels and prolonged reaction times. [ABSTRACT FROM AUTHOR]

Doping semiconducting oxides, such as LaFeO3 (LF), with metallic elements is a good strategy to improve the performance of photocatalysts. In this study, LF and ten different nanopowders metal-doped at the La or Fe site of LaFeO3 were evaluated in the photocatalytic degradation of ciprofloxacin (CP) and oxytetracycline (OTC). The following metals were used in the doping (mol%) process of LF: Pd 3% and 5%; Cu 10%; Mg 5%, 10%, and 20%; Ga 10%; Y 10% and 20%; and Sr 20%. The doped samples were synthetized using a citrate auto-combustion technique. From the X-ray diffraction (XRD) data, only a single crystalline phase, namely an orthorhombic perovskite structure, was observed except for trace amounts of PdO in the sample with Pd 5%. The specific surface area (SSA) ranged from 9 m2 g−1 (Ga 10%) to 20 m2 g−1 (Mg 20%). SEM images show that all samples were constituted from agglomerates of particles whose sizes ranged from ca. 20 nm (Mg 20%) to ca. 100 nm (Pd 5%). Dilute aqueous solutions (5 × 10−6 M) prepared for both CP and OTC were irradiated for 240 min under visible-light and in the presence of H2O2 (10−2 M). The results indicate a 78% removal of OTC with Cu 10% doped LF in a phosphate buffer (pH = 5.0). The degradation of CP is affected by pH and phosphate ions, with 78% (in unbuffered solution) and 54% (in phosphate buffer, pH = 5.0) removal achieved with Mg 10% doped LF. The reactions follow a pseudo-first order kinetic. Overall, this study is expected to deepen the assessment of photocatalytic activity by using substrates with different absorption capacities on photocatalysts. [ABSTRACT FROM AUTHOR]