Search

In response to growing concerns regarding the environmental impact of traditional chemical synthesis methods, this study delves into the phytoconstituents-based green synthesis of copper oxide (CuO) nanoparticles (NPs) as a promising alternative. The study aimed to synthesize CuO NPs using eco-friendly methods with Erythrina variegata and then explore their anticancer, antibacterial, and photocatalytic properties. CuO NPs' structural and optical properties were comprehensively analyzed using UV-vis, XRD, FTIR, XPS, DLS, SEM, and HRTEM, with elemental mapping performed via EDAX. Cytotoxicity assays were conducted on cervical cancer HeLa cells and HEK293 noncancerous cells. The band gap of the CuO NPs was determined to be 3.781 eV, with a crystal size of 17.15 nm and a zeta potential of −23.1 mV. Remarkably, the synthesized nanoparticles exhibited a spherical morphology and demonstrated significant cytotoxicity against HeLa cells with an IC50 value of 48 ± 5 μg mL−1 while displaying lower toxicity towards HEK293 cells. Additionally, the prepared CuO NPs demonstrated dose-dependent anticancer potential, inhibiting cell migration and colony formation, and inducing apoptosis in HeLa cells. Moreover, the antibacterial activity of the prepared CuO NPs against S. aureus and E. coli paralleled that of the standard antibiotic streptomycin. Furthermore, we evaluated the photocatalytic capability of the developed CuO NPs, which demonstrated significant photocatalytic activity with a 91.12% degradation of the organic dye methylene blue in 180 min under UV irradiation, demonstrating their potential for breaking down organic pollutants in the environment. This study emphasizes the eco-friendly synthesis of CuO NPs, promising significant impacts on energy, the environment, and medicine through sustainable approaches. [ABSTRACT FROM AUTHOR]

Comprehensive strategies with the development of advanced materials are required for the remediation of water and land pollution to protect the environment and human health. In this regard, iron oxide catalysts are recognized as preferable catalysts for the heterogeneous photo-Fenton process, which is an efficient technique for degrading organic pollutants in waste water. The present study discusses the photocatalytic performance of iron oxide-based catalysts synthesized from industrial waste red mud for methylene blue degradation under visible light irradiation. XRD studies confirmed the formation of a pure α-Fe2O3 (hematite) phase, whereas the doping of iron oxide with Mn, Cu, and Ce was ascertained by XPS analysis. 3 wt% Cu doped iron oxide with a TOC value of ∼84.7% showed the best removal efficacy to the tune of ∼91% within 60 min of visible light irradiation. Impedance data supports the enhanced charge separation in metal doped α-Fe2O3, which improves the photocatalytic performance. A similar trend was observed in photo-electrochemical (PEC) properties, where Cu doped Fe2O3 showed 2 times higher photocurrent than the bare one. Based on scavenging tests, electrons and hydroxyl radicals (˙OH) were shown to be major players in the photodegradation of pollutants under visible light. A probable mechanism explaining the enhanced e−/h+ pair separation and migration was proposed by examining electrochemical properties. This work has significant implications for wastewater treatment with the efficient use of industrial waste red mud as a cost-effective resource. [ABSTRACT FROM AUTHOR]

Pigments play a pivotal role in the cosmetic industry, in which the development of pigments with concurrent color diversity, hydrophobicity, biocompatibility and photostability remains a great challenge. Herein, we report organic–inorganic composite pigments synthesized via a combination of organic dye anions (Ponceau SX and acid green (AG)), layered double hydroxides (LDHs) and octyltriethoxysilane (OTEOS) (denoted as O/Dye-LDHs: O/SX-LDHs and O/AG-LDHs).The prepared composite pigments were characterized via a comprehensive investigation based on X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS-mapping), Fourier transform infrared (FT-IR) spectroscopy, CIE 1976 L*a*b* color scales, static contact angle measurement and HET-CAM assay. The results confirm the successful intercalation of organic dye anions into the interlayer region of LDHs via host–guest interactions and the surface modification of OTEOS on the layer surface, forming a new kind of hydrophobic organic–inorganic composite pigment with a sandwich structure. LDH layer protection and OTEOS coating play crucial roles in the high photostability, good hydrophobicity and satisfactory biocompatibility of pigments. In addition, O/Dye-LDHs exhibit rich color and color adjustability. Impressively, we applied mixture composite pigments with different O/SX-LDH-to-O/AG-LDH ratios to formulate an eye shadow cream, which present a series of popular and natural colours with water resistance to enhance one's attractiveness and appearance. This work provides a promising strategy for the design of safe and efficient composite pigments, demonstrating their potential application in the field of makeup. [ABSTRACT FROM AUTHOR]

Borophene is an emerging two-dimensional material exhibiting exceptional piezocatalytic activity under the influence of ultrasonic vibrations, as exemplified herein by the decomposition of highly stable organic dyes in water. After 6 minutes of exposure, borophene sheets converted up to 92 percent of a mixture of dye molecules at room temperature. [ABSTRACT FROM AUTHOR]

The addition of PnBu3 to o-substituted dianiline squaraine dyes leads to bench stable ylides. Exposure to a metal analyte in solution, results in PIII abstraction and rapid disruption of the ylide conjugation to promote reversion back to the squaraine dye giving an immediate turn-on colorimetric response. The stoichiometric sensitivity and accessibility of these chemodosimeters constitute effective organic dyes for trace transition metal detection. [ABSTRACT FROM AUTHOR]

It is necessary to develop methods for rapid degradation of untreated waterborne contaminants due to their serious impact on the environment and human health. Here, we proposed a rapid and efficient microplasma electrochemistry (MIPEC) method for organic dye and antibiotic degradation. The atmospheric-pressure plasma acted as the anode and it could generate reactive radicals for rapid and complete degradation of rhodamine B (RhB) in about 6 min, which is one of the fastest methods to our knowledge. Similarly, the degradation of ciprofloxacin (CIP) has also been achieved. This method with mild and convenient operation conditions could be applied in a wide pH range due to the unique properties of the plasma anode, unrestricted by the pH of wastewater. The mechanism study revealed that more reactive species could be generated at the plasma anode than at the cathode, leading to a faster reaction rate at the anode side and the presence of oxygen could also accelerate the generation of reactive species. Besides, the MIPEC method can be used to treat a variety of dyes separately and together in minutes in different water bodies, making it a universal method suitable for treating different dyes in wastewater. This work provides a rapid and efficient method for waterborne contaminant degradation without any secondary pollution and need for post treatment, and also broadens the application field of the MIPEC method. [ABSTRACT FROM AUTHOR]

Among other photovoltaic techniques including perovskite solar cells and organic solar cells, dye-sensitized solar cells (DSSCs) are considered to be a potential alternative to conventional silicon solar cells. Porphyrins are promising dyes with the properties of easy modification and superior light-harvesting capability. However, porphyrin dyes still suffer from a number of unfavorable aspects, which need to be addressed in order to improve the photovoltaic performance. This feature article briefly summarizes the recent progress in improving the Voc and Jsc of porphyrin-based DSSCs in terms of molecular engineering by modifying the porphyrin macrocycle, donor and acceptor moieties of the porphyrin dyes, coadsorption of the porphrin dyes with bulky coadsorbents like chenodeoxycholic acid (CDCA), and cosensitization of the porphyrin dyes with metal-free organic dyes. Notably, concerted companion (CC) dyes are described in detail, which have been constructed by linking a porphyrin dye subunit and a metal-free organic dye subunit with flexible alkoxy chains to achieve panchromatic absorption and concerted enhancement of Voc and Jsc. In one sentence, this article is expected to provide further insights into the development of high performance DSSCs through the design and syntheses of efficient porphyrin dyes and CC dyes in combination with device optimization to achieve simultaneously elevated Voc and Jsc, which may inspire and promote further progress in the commercialization of the DSSCs. [ABSTRACT FROM AUTHOR]

In this paper, three-dimensional TiO2 nanoflowers (NFs) were prepared by a facile hydrothermal method, and Ag3PO4 was grown in situ following alkali treatment to design and synthesize a Ag3PO4/OH/TiO2 catalyst with excellent photocatalytic activity under visible light. The test results show that the photocatalytic degradation performance of TiO2 NFs after alkali treatment and Ag3PO4 loading is significantly improved. This is because the alkali treatment and the introduction of Ag3PO4 can provide a large amount of –OH, which can be converted to ˙OH under UV irradiation, followed by an increase in the number of active radicals to enhance the photocatalytic degradation performance. Meanwhile, the introduction of Ag3PO4 can effectively improve the light absorption ability of the photocatalyst. Moreover, the in situ growth of Ag3PO4 on TiO2 NFs can construct a high-quality Ag3PO4/TiO2 heterojunction to promote the charge separation and transport. Therefore, the degradation rate of Ag3PO4/OH/TiO2 can reach 90% after 30 min for degrading 3 mg L−1 RhB under visible light. The Ag3PO4/OH/TiO2 photocatalyst designed in the present work provides a new tool for the degradation of organic dyes. [ABSTRACT FROM AUTHOR]

Subphthalocyanines (SubPcs) have emerged as promising organic dyes for the development of efficient artificial photosynthetic devices, offering intense absorption in the visible region along with excellent charge transport properties. In this study, four novel SubPc derivatives containing carboxylic acid and various peripheral substituents were synthesized as a panchromatic photosensitizer to prepare an efficient and stable TiO2-based photocatalytic system for co-catalyst-free photocatalytic hydrogen evolution. To compare the influence of the nature of the peripheral substituents on photocatalytic activity, SubPc derivatives (coded as SubPc 1–4) were decorated with substituents having different electron-donating capabilities, such as alkyl thio, benzodioxin, amine, and iodo units, respectively. Photocatalytic activities were examined in the presence of TEOA as a sacrificial agent under irradiation with λ > 400 nm without co-catalyst loading. SubPc 1/TiO2 shows the best photocatalytic activity among the SubPc-sensitized photocatalysts, with a hydrogen evolution rate of 0.176 mmol h−1. While the activity of all four SubPc-based photocatalysts increased significantly after 24 h irradiation, notably, SubPc 1/TiO2 exhibited remarkable catalytic activity, achieving a hydrogen evolution rate of 6.017 mmol with a high turnover number (TON) value of 12 279 for hydrogen production. This study highlights the potential of SubPc-based sensitizers for co-catalyst-free photocatalytic H2 production and offers valuable insights into the impact of peripheral units in SubPc/TiO2-based photocatalytic systems. [ABSTRACT FROM AUTHOR]

A novel ethylene-bridged silsesquioxane was synthesized by a heat-induced thiol–ene addition reaction of 2-acetylthioethanethiol to 1,2-bis(triethoxysilyl)ethene. Upon deacetylation, the formed organosiloxane precursor bearing the dithiol moiety (–SCH2CH2SH) self-assembled into a sulfur-rich PMO material in the presence of the structure-directing agent under acidic conditions. The loading of sulfur-bound ligands in the PMO framework can be adjusted by co-condensing the precursor with tetraethyl orthosilicate. The structure of the resulting PMOs was characterized by powder X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy, infrared spectroscopy, and nitrogen adsorption and desorption studies. The PMO prepared by using the thio-bis-silane precursor alone can be used for efficient and fast capture of mercury ions from water with a saturation Hg(II) uptake capacity of 1253 mg g−1 and recycled several times with negligible loss in the adsorption efficiency. This material also showed a high adsorption selectivity for Hg(II) over other competitive metal ions like Zn2+, Pb2+, Fe3+, Cu2+ and Mn2+. Remarkably, the new adsorbent proved to be effective for simultaneously removing Hg(II) and rhodamine B (RhB) from simulated sewage with removal rates of over 97% and 91% for both at 100 ppm, respectively, indicating its potential for the practical application in environmental remediation. [ABSTRACT FROM AUTHOR]

Works of art, especially paintings, often involve successive layers of materials of diverse compositions and properties. The current study explores the potentialities of the combination of femtosecond Laser Induced Breakdown Spectroscopy (fs-LIBS) and Macro X-ray Fluorescence (MA-XRF) for the study of paintings. In this framework, two mock-up samples that were manufactured by using traditional post-byzantine painting methods and numerous inorganic and organic pigments was thoroughly investigated. The selected pigments were either applied as single paint layers on top of a calcium carbonate substrate or as a combination of two and/or three successive paint layers over the substrate. The authors attempt to disclose the layered structure of the paints by inspecting some carefully chosen LIBS spectral features (markers) as a function of the laser shot number. The various paint layers are identified by applying less than ten laser shots while the diameter of the induced craters is limited to under 100 μm. Additionally, it is shown that through the proper treatment and evaluation of complementary MA-XRF data, one may overcome some of the fs-LIBS limitations and thoroughly investigate a painting's stratigraphy. Given the micro-invasive character of fs-LIBS and the non-invasive character of MA-XRF, combining the selected analytical methods is a promising tool for painting investigation. [ABSTRACT FROM AUTHOR]

Highly efficient and low-cost materials for the degradation of organic dyes in wastewater remain the focus of environmental protection and water pollution control, in which, nanozymes have been at the forefront for the development of a new platform and aroused more and more attention. In this work, a nanoceria@shaddock peel-derived nanocomposite (Ce@CSP) with excellent peroxidase-like performance in methyl violet (MV) degradation as well as ascorbic acid (AA) detection was synthesized by a simple one step in situ pyrolysis of cerium ammonium nitrate (Ce(NH4)2(NO3)6) and pretreated shaddock peel. By means of the cooperative-reinforcing peroxidase-like activity of the porous carbon material originating from shaddock peel (CSP) and the loaded CeO2 nanoparticle, the obtained nanozyme Ce@CSP displayed a superior catalytic ability in the catalyzed oxidation of the chromogenic substrate 3,3′,5,5′-tetramethylbenzidine (TMB) in the presence of H2O2. Specifically, a synergetic absorbent property was also demonstrated by the porous carbon material, bringing the target molecules in close proximity to the nanozyme catalyst and therefore enabling effective decoloration of MV and colorimetric detection of AA with a linear range of 1.6–17.3 μM and a detection limit of 1.07 μM. The current work has realized effective decoloration of MV in real water samples and provided a wide range of potential applications of low-cost and eco-friendly materials in organic dye treatment. [ABSTRACT FROM AUTHOR]

Safranine-catalyzed oxidative cyclization reaction of substituted 2-aminobenzamides and aldehydes utilizing oxygen as a green oxidant under visible light conditions at room temperature has been developed. Good to excellent yields of the desired quinazolinone products were achieved. Furthermore, the presented procedure illustrates the applicability of gram scale reactions. [ABSTRACT FROM AUTHOR]

A ferrocene carboxylic acid (Fc)-doped copper–p-phthalic acid metal–organic framework material (Fc–Cu PTA) exhibited remarkably high peroxidase-mimicking activity, while Cu PTA showed nearly no peroxidase-mimicking activity. Under the enzymatic catalysis of Fc–Cu PTA as a peroxidase-mimicking nanozyme, the tested organic dyes were rapidly degraded by peroxymonosulfate. Fc–Cu PTA could be an effective catalyst for the degradation treatment of dye-polluted water and soil sources, and potentially for other peroxidase-related applications as well. [ABSTRACT FROM AUTHOR]

Graphene oxide (GO) lamellar membranes have attracted a lot of attention as a possible solution for water purification applications. In this work, asparagine amino acid-modified GO-based membranes (As@GO) are prepared with different thicknesses. The as-prepared As@GO-based membranes are used for the separation of organic dyes and heavy metal ions. The 300 nm-thick As@GO multilayer membrane shows high rejection, i.e., 99.8% and 99.9% of methylene blue (MLB) and rhodamine B (RB) dyes, respectively, along with an exceptional water permeability of ∼1740 ± 10 L m−2 h−1 bar−1. Furthermore, the As@GO membrane also demonstrates excellent rejection of up to 95.6% and 96.7% for cadmium (Cd2+) and lead (Pb2+) ions, respectively. These membranes are also highly stable in water for up to 34 days and do not swell. These results suggest the valuable experimental basis for the design and development of stable GO membranes (GOMs) with high permeability and superior separation selectivity for applications in the separation fields of valuable metal ion extraction from seawater and other wastewater purification, etc. [ABSTRACT FROM AUTHOR]

Metal–organic frameworks and coordination polymers (MOFs/CPs) have emerged as a rare category of multidimensional materials with applications in many fields, particularly as photocatalysts for aromatic dyes and for the luminescent sensing of volatile organic solvents (VOCs), anions, cations, etc. Herein, a luminescent zinc(II) coordination polymer (ZnCP) was prepared using 3,5-diamino triazole (DAT) and 1,3,5-benzenetricarboxylic acid (BTC) under solvothermal conditions and was fully characterized by FTIR spectroscopy, powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), Brunauer–Emmett–Teller (BET) analysis, and single X-ray crystallography. Moreover, the photocatalytic performance of the ZnCP in decomposing an aqueous solution of methyl green (MG) was examined. Photocatalysis results indicated a 99.61% efficiency in the presence of the ZnCP under visible light. Furthermore, an active species trapping experiment helped deduce a possible photocatalysis mechanism of MG degradation. Interestingly, the ZnCP also acted as a potential luminescent sensor for the detection of cations Fe3+ and Cu2 and anions Cr2O72− and MnO4−, with outstanding limit of detection (LOD) values of 2.44 nM for Fe3+, 3.50 nM for Cu2+, 3.14 nM for Cr2O72−, and 2.54 nM for MnO4−. Thus, the designed luminescent zinc(II) coordination polymer holds the potential to act as a photocatalyst as well as a luminescent sensor. [ABSTRACT FROM AUTHOR]

Considering the strong sunlight-absorption property of WS2 and the good photocatalytic activity of BiOCl, a solar-light-active Z-scheme BiOCl@WS2 nanocomposite photocatalyst was synthesized by a precipitation approach. The developed photocatalyst was systematically characterized using available precision instruments. The photocatalytic property of the synthesized photocatalyst toward methyl orange (MO), rhodamine B (RhB), and crystal violet (CV) as anionic and cationic model organic dyes was investigated. In addition, the influence of operational factors, such as the catalyst dose, dye concentration, and pH, on the photocatalytic performance of the proposed photocatalyst was examined. The degree of mineralization of the fabricated Z-scheme BiOCl@WS2 nanocomposite photocatalyst during photodegradation of CV was also evaluated via total organic content (TOC) measurements. The findings showed that the developed Z-scheme BiOCl@WS2 nanocomposite exhibited excellent photocatalytic properties toward the organic pollutants MO, RhB, and CV. Moreover, the nanocomposite exhibited a better photocatalytic activity when compared with that of the solar-light-active photocatalysts reported in the open literature. It also displayed the potential to photocatalytically degrade 81% of MO, 100% of RhB, and 95% of CV within 120 min. Besides, 88% of CV could be mineralized by the fabricated photocatalyst in two hours. The outstanding photocatalytic performance of the Z-scheme BiOCl@WS2 nanocomposite could be attributed to the narrow band gap, large surface area, extended optical activity, and suppressed charge recombination rate. Thus, this work opens the door for developing effective, efficient, and stable solar-light-active photocatalysts for the photodegradation of organic dyes in wastewater. [ABSTRACT FROM AUTHOR]

A novel metal-free and environment-friendly approach for synthesizing biologically important moieties, benzothiazoles and benzimidazoles, under visible light irradiation using photocatalyst Eosin Y, ethanol:water as a green solvent and atmospheric air as an oxidant has been developed. Using an organic dye, Eosin Y, provided a mild and economical catalytic system to synthesize a series of benzothiazoles and benzimidazoles in good to excellent yields. Besides, the photocatalytic system does not require an additional oxidant, which is good for the environment. This method has several advantages, including the absence of metals, low cost, environmental friendliness, green solvent, non-toxicity, ease of handling, and renewable energy sources such as visible light. [ABSTRACT FROM AUTHOR]

Organic dye wastewater is a tremendous threat to the environment and human beings. Adsorption as a simple but effective approach for dye removal has attracted widespread attention. However, this promising method is dictated by the development of highly cost-effective adsorbents. Porous organic polymers (POPs) as a new type of porous adsorbent for efficient dye removal have exhibited tremendous potential. However, the scalable production of POPs is still a tremendous challenge, due to the very poor availability of building blocks, often involving tedious synthesis and extremely expensive starting materials. In this study, a kind of carbamate-based POP (CPOP) was designed and synthesized by a simple urethane reaction in one step between 4,4′-diphenylmethane diisocyanate and phloroglucinol without any catalysts. The structure and physicochemical properties of CPOPs were fully characterized and the adsorption and removal performances of organic dyes in water were evaluated. The results indicated that CPOPs with high stability can efficiently and selectively adsorb methylene blue (one of the most widely used dyes) in water. Considering the simple and easy-to-scaleup preparation process and commercially available low-cost raw materials, CPOPs as adsorbents have great potential for use in the treatment of dye wastewater. [ABSTRACT FROM AUTHOR]

The problems of easy oil contamination, easy oxidation, and low dye removal ability of 2D MXene hinder its practical application in high-efficiency oil/water separation and dye removal. In this study, Ti3C2Tx was first modified using NH3·H2O to obtain intercalated Ti3C2Tx (TN), and then, N-[3-(trimethoxysilyl) propyl] ethylenediamine (AEAPTMS) was used to conduct the surface aminated-modification of TN to achieve functional Ti3C2Tx (TN–AEAPTMS), which was then loaded onto polyurethane (PU) sponge to get TN–AEAPTMS@PU sponge. The low oil adhesion and super hydrophilicity/underwater super oleophobicity of TN–AEAPTMS@PU sponge enable excellent separation performance for oil/water mixtures of different densities. After being soaked in water for 45 days, TN–AEAPTMS can still maintain its original accordion-like morphology and hold good oil/water separation performance, overcoming the performance degradation caused by easy oxidation of Ti3C2Tx under water. More importantly, TN–AEAPTMS@MCE, which is acquired through vacuum suction filtration with TN–AEAPTMS loaded onto mixed cellulose ester microporous membrane, can remove various anionic and cationic organic dyes with high flux and removal rate, innovatively overcoming the poor adsorption performance of Ti3C2Tx for anionic dyes. Therefore, the TN–AEAPTMS composite exhibits excellent potential for practical applications in oil/water separation and dye removal. [ABSTRACT FROM AUTHOR]

The construction of photocatalysts with a Z-scheme heterojunction is considered to be a superior strategy for improving photocatalytic activity. In this study, a photocatalyst (PI/TiC/TiO2) with a Z-scheme heterojunction was fabricated, in which polyimide (PI) and TiO2 were used as the organic/inorganic semiconductor photocatalyst and TiC acted as the transmission bridge for electrons between PI and TiO2. In the self-made air flow photocatalytic reactor, the photocatalytic degradation efficiencies of organic dyes by PI/TiC/TiO2 increased with the increase of both the concentration and diffusion rate of O2. The degradation efficiencies of RhB and MB by PI/TiC/TiO2 reached 93.87% and 90.96%, respectively, within 90 min of visible light exposure, showing its outstanding photocatalytic performance. The mechanism analysis indicated that the Z-scheme heterojunction in PI/TiC/TiO2 facilitated the separation and migration of photoexcited charges while retaining stronger redox capabilities for charge carriers. This study provides an insight into the construction of visible light responsive organic/inorganic photocatalysts with Z-scheme heterojunctions for organic pollution treatment applications. [ABSTRACT FROM AUTHOR]

Traditional water-soluble organic macrocyclic receptors generally lack photofunctionality, thus monitoring the drug delivery and the phototheranostic applications of these host–guest macrocyclic systems has been greatly restricted. To address this issue, incorporating π-conjugated dye chromophores as building blocks into macrocyclic molecules is a straightforward and promising strategy. This approach not only imparts intrinsic optical features to the macrocycles themselves but also enhances the host–guest binding ability due to the large planar structures of the dyes. In this feature article, we focus on recent advances in water-soluble macrocyclic compounds based on organic dye chromophores, such as naphthalimide (NDI), perylene diimides (PDI), azobenzene (azo), tetraphenylethylene (TPE) and anthracene, and provide an overview of their various applications including molecular recognition, drug release, biological imaging, photothermal therapy, etc. We hope that this article could be helpful and instructive for the design of water-soluble dye-based macrocycles and the further development of their biomedical applications, particularly in combination with drug therapy and phototheranostics. [ABSTRACT FROM AUTHOR]

In this paper, we employ density functional theory (DFT) simulations to predict the energy conversion efficiency of a novel class of organic dyes based on linear carbon chain (LCC) linkers for application in dye-sensitized solar cells (DSSCs). We investigate the role of the anchoring group, which serves as a bridge connecting the linker and the surface. Specifically, we compare the performance of cyanoacrylic acid, dyes PY-4N and PY-3N, with that of phosphonate derivatives, dyes PY-4NP and PY-3NP, wherein the carboxylic group of the cyanoacrylic moiety is replaced with phosphonic acid. The observed variations in the UV/VIS absorption spectra have a slight impact on the light harvesting efficiency (LHE). Based on the empirical parameters we have taken into account, the electron injection efficiency (Φinj) and electron collection efficiency (ηcoll) values do not impact the short-circuit current density (JSC) values of all the studied dyes. The open-circuit voltage (Voc) is theoretically predicted using the improved normal model (INM) method. Among the dyes, PY-4N and PY-3N demonstrate the highest Voc values. This can be attributed to a more favorable recombination rate value, which is related to the energy gap between the HOMO level of the dyes and the conduction band minimum (CBM) of the surface. Dyes PY-4N and PY-3N are predicted to demonstrate remarkably high photoelectric conversion efficiency (PCE) values of approximately 21.79% and 16.52%, respectively, and therefore, they are expected to be potential candidates as organic dyes for applications in DSSCs. It is worth noting that PY-4NP and PY-3NP exhibit strong adsorption energy on the surface and interesting PCE values of 11.66% and 8.29%, respectively. This opens up possibilities for their application in DSSCs either as standalone sensitizers or as co-sensitizers alongside metal-free organic dyes or organic–inorganic perovskite solar cells. [ABSTRACT FROM AUTHOR]

Environmental issues have always been a concern, and designing a material that can effectively combat both gaseous and liquid pollutants is a goal we are working toward. Herein, two examples of N-rich covalent organic frameworks (COFs), named YCOF1 and YCOF2, were synthesized using the solvothermal method. Their structure, stability and morphology were characterized using PXRD, FT-IR, XPS, TGA and SEM. According to the Brunauer–Emmett–Teller (BET) method, the specific surface areas of YCOF1 and YCOF2 were 559.096 and 741.261 m2 g−1, respectively. Under the volume percentage of simulated flue gases, YCOF1 exhibits excellent CO2 IAST selectivities of 70.97 at 273 K and 30.05 at 298 K, while YCOF2 also exhibits excellent CO2 IAST selectivity of 51.90 at 273 K. Moreover, their high specific surface area and abundant active sites provide excellent adsorption capacity for malachite green (MG), with maximum adsorption amounts of 650.14 mg g−1 (YCOF1) and 572.95 mg g−1 (YCOF2). Furthermore, the adsorption of the COFs for dyes followed the pseudo-second-order kinetic model and the Langmuir isothermal adsorption model. The dye removal efficiency of YCOF1 and YCOF2 showed less than 5% change after 5 adsorption cycles. [ABSTRACT FROM AUTHOR]

The development of photocatalysis is hindered, in part, by the quick recombination of photogenerated carriers and the instability of light sources. In this study, the problem of too-fast electron–hole pair compounding in photocatalysis is effectively regulated by the polarization field of pyroelectric materials using the pyroelectric method. Self-polarized pyroelectric materials that depend on temperature variations can generate usable electrical energy and polarized charge carriers to degrade organic pollutants. Pb(Mg1/3Nb2/3)O3–PbTiO3 (PMN–PT) is a relaxor ferroelectric material with spontaneous polarization characteristics. The PMN–0.30PT:1 mol%Sm3+ catalyst was prepared by applying the high-temperature solid-state reaction method. Under the dark condition and nine cold–hot cycles of 23 °C–68 °C, using H2O2-assisted PMN–0.30PT:1 mol%Sm3+ as a catalyst, the degradation rate of rhodamine 6G (10 mg L−1) was 94.3 ± 2.5%. In addition, the degradation rates of 88.52% and 64.32% were obtained for rhodamine B (10 mg L−1) and methylene blue (10 mg L−1), respectively. This study provides a new approach to the pyroelectric catalytic degradation of organic pollutants. [ABSTRACT FROM AUTHOR]

In this study, a new cobalt-based metal–organic framework (JLNU-500), [Co2(OH)(PBA)(AIP)]·3DMA·0.75H2O (4-(pyridin-4-yl) benzoic acid (HPBA), 5-aminoisophthalic acid (H2AIP) and N,N-dimethylacetamide (DMA)), was fabricated using a solvothermal method. JLNU-500 has 3D network architecture with 1D nanopore channels. The prepared JLNU-500 can activate peroxymonosulfate (PMS) for Rhodamine B (RhB) dye decolorization. Interestingly, catalyst JLNU-500 exhibited high efficiency for PMS activation, and nearly 100% (above 99.8%) removal of RhB with a high concentration (50.0 mg L−1, 100 mL) was achieved within 6 min. The reaction rate constant of the JLNU-500/PMS system was 1.02 min−1 calculated based on the pseudo-first-order kinetics, which is higher than that of the other reported catalysts. Furthermore, the factors, which could influence PMS activation were also investigated, such as PMS dosage, catalyst dosage, pollutant RhB concentration, reaction temperature and solution pH. More importantly, the radical trapping experiments ferreted out that sulfate (SO4˙−) and hydroxyl (˙OH) radicals were the dominating oxidants in the removal of RhB. Moreover, the possible degradation mechanism was elucidated. This study provides new prospects for fabricating new MOFs that can potentially be employed for high-efficiency catalytic oxidation as heterogeneous catalysts. [ABSTRACT FROM AUTHOR]

Herein we report that a surfactant modified quantum dot-complex (S-QDC; with λem-515 nm) nanocomposite, as a donor fluorophore, exhibits enhanced Förster resonance energy transfer (FRET) efficiency to an acceptor organic dye (λem-576 nm) in comparison to only the QDC. The proposed S-QDC (consisting of a ZnS quantum dot, zinc quinolate inorganic complex and cetyltrimethylammonium bromide (CTAB) surfactant) provides the unique and selective ratiometric visual detection of organic dyes present as food colorants in commercial chili powder, tomato ketchup and mixed fruit jam. Notably, the S-QDC shows a limit of detection (LOD) as low as 2.2 nM in the linear range of 0.17–4.89 μM for food colorants. Furthermore, the present work will bring new possibilities to unravelling the chemistry among surfactants, inorganic complexes and quantum dots to make newer optical materials with futuristic scope of utilization ranging from optical sensors to light emitting devices. [ABSTRACT FROM AUTHOR]

Layer-by-layer assembly of strong polyelectrolytes was successfully implemented on hydrophobic particles in degassed saline water thanks to de-gassing-reduced hydrophobic interactions and salinity-reduced hydration. The resulting polyelectrolyte multilayer coated particles were readily converted to hydrophobic yolk/hydrophilic shell particles for the removal of organic dyes from water via both electrostatic and hydrophobic interactions. [ABSTRACT FROM AUTHOR]

Most conventional dye treatment methods have limited efficacy as they are expensive, time-intensive and result in incomplete dye removal from water. Addressing these issues, this work reports the fabrication of a NaTiO3/g-C3N4 heterojunction photocatalyst, which was utilized for the advanced oxidation process under sunlight irradiation to remove crystal violet (CV) and methylene blue (MB) dyes and their binary mixture. The perovskite NaTiO3 is synthesized via a simple hydrothermal method and combined with graphitic carbon nitride, formed through the thermal decomposition of melamine, to fabricate the heterojunction. The scanning electron microscopy (SEM) images reveal that spherical NaTiO3 nanoparticles are aggregated on the sheet-like surface of g-C3N4 and structural analysis utilizing the XRD pattern confirms the formation of a heterojunction. From the Tauc plot the bandgap of the material is estimated to be 2.3 eV. The complete degradation of MB was observed within 25 min, while CV and the binary mixture require 20 min for complete degradation. The high visible light absorption of NaTiO3 and large surface area of g-C3N4 were attributed to the enhanced catalytic performance of the heterojunction. Additionally, scavenger studies indicated that the radical species h+ and +OH played a crucial role in the photocatalytic degradation of the dyes. Reusability studies confirm good stability up to five cycles of dye degradation. The results establish the NaTiO3/g-C3N4 heterojunction as an efficient photocatalyst to remove organic dyes from water, thus having immense potential in water purification. [ABSTRACT FROM AUTHOR]

Hydrothermal synthesis was used to create four different POM-based compounds, namely {[Co(Hptpm)2(β-Mo8O26)0.5(ξ-Mo8O26)0.5]}·H2O (1), [Co(Hptpm)2(δ-Mo8O26)]·H2O (2), [Co(Hptpm)2(β-Mo8O26)] (3) and [Zn(Hptpm)2(β-Mo8O26)] (4) (ptpm = 4-[3-(3-pyridine-2-yl-[1,2,4]triazol-4-yl)-propyl]- morpholine). 1-4 containing different octamolybdate isomers were characterized. Compounds 1-4 showed good electrochemical performance and can be utilized as bifunctional sensors for NO2 -, H2O2, Cr(VI) and Fe(III). Taking compound 1 as an example, the detection limits are 0.081 μM for NO2 -, 0.072 μM for H2O2, 0.054 μM for Cr(VI) and 0.063 μM for Fe(III), respectively. Compounds 1-4 have good capacitance. Moreover, compounds 1-4 also show good adsorption properties for organic cationic dyes. The cationic dyes include methylene blue (MB), crystal violet (CV) and neutral red (NR). In addition, 1-4 have excellent characteristics that can reduce Cr(VI) to Cr(III) by photocatalytic technology. Within 30 min, the reduction rates were 95.85% for 1, 93.99% for 2, 90.29% for 3 and 88.18% for 4. [ABSTRACT FROM AUTHOR]

The discovery of nanoparticles with varied size, shape and composition has stretched the limits of nanotechnology in almost any field. One of the important areas of interest is the use of nanoparticles in heterogeneous catalysis, whereby it offers an advantage by providing large surface area. Our present work focussed on the development of a graphene-based nanocatalyst (Pd@NGO) as an efficient tool to study various organic transformations. The prepared mesoporous catalyst was characterised by X-ray diffraction (PXRD), thermogravimetric analysis (TGA), field emission-scanning electron microscopy (FE-SEM), Brunauer–Emmett–Teller (BET), high resolution transmission electron microscopy (HR-TEM) and Fourier transformer infrared spectroscopy (FT-IR), inductively coupled plasma atomic emission spectroscopy (ICP-AES) and X-ray photoelectron spectroscopy (XPS). TEM images showed the light grey sheets of N-GO on which Pd(0) nanoparticles were immobilised. BET analysis confirmed the mesoporous texture of the designed nanocatalyst by giving the surface area of 12.933 m2 g−1 with a pore volume and average pore diameter of 0.020685 cm3 g−1 and 6.39 nm, respectively. Also, FTIR data affirmed the presence of a characteristic C–N peak near 1271 cm−1 showing successful doping of nitrogen over graphene oxide. The XPS data revealed the presence of various elements like carbon (C 1s), nitrogen (N 1s), oxygen (O 1s) and Pd 3d. The prepared nanocatalyst was explored in Suzuki coupling reaction under green conditions, reduction of nitro compounds and the photodegradation of methyl orange with a degradation efficiency of 98.77%. The photodegradation of dyes is viewed as a potential method for the treatment of industrial wastewater due to its low cost, ecologically acceptable procedure, and lack of secondary contamination. Through direct photodegradation or a degradation process involving sensitization, this approach exhibits the light-enhanced creation of charge carriers and reactive radicals that non-selectively break down a variety of organic dyes into water, CO2, and other organic molecules. Moreover, Pd@NGO shows excellent stability and can be used multiple times, and hence possesses efficient reusability. [ABSTRACT FROM AUTHOR]

Nanoparticle mediated photo-induced hyperthermia holds much promise as a therapeutic solution for the management of diseases like cancer. The conventional methods of temperature measurements do not measure the actual temperature generated in the vicinity of the nanoparticles during illumination. In contrast, nano temperature sensors built on hyperthermic nanoparticles can relay local temperatures around the nanoparticles during thermal induction. In this study, we present a core shell construct consisting of a plasmonic core and a silica shell encapsulating a FRET pair of organic dyes for such application. The plasmonic core imparts photo-induced hyperthermic properties to the nanoconstruct, while the fluorescent shell enables ratiometric sensing of temperature. We see that even at a low dye encapsulation concentration, the shell displays a linear ratiometric fluorescence response to temperature and high energy transfer between the dye pair. Interestingly, Monte Carlo simulations, without considering the plasmonic core, show that the energy transfer in the system should be much smaller than that observed, confirming plasmon enhancement in the FRET energy transfer. We also show the ratiometric temperature measurement using these particles during photoinduced hyperthermia. This study suggests the use of plasmonic nanoparticles in the next generation "self-limiting" photothermal therapy. [ABSTRACT FROM AUTHOR]

α-FeOOH (goethite) with a nanorod morphology has been synthesized successfully by a hydrothermal method, and further calcinated (6 h at 520 °C) to obtain α-Fe2O3 (hematite) nanoparticles of spherical shape morphology. The synthesized α-FeOOH and α-Fe2O3 nanoparticles were subjected to various characterization techniques (X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), UV-Vis diffuse reflectance spectroscopy (UV-DRS), photoluminescence (PL) spectroscopy, liquid chromatography with mass spectrometry (LCMS), dynamic light scattering (DLS) and zeta potential (ZP), thermogravimetry analysis (TGA), differential thermal analysis (DTA), X-ray photoelectron spectrometer (XPS), N2 adsorption–desorption isotherms (BET), field emission scanning electron microscopy (FESEM), energy dispersive X-ray analysis (EDAX) and transmission electron microscopy (TEM)). Meanwhile, the as-synthesized α-FeOOH and α-Fe2O3 nanoparticles were used to degrade hazardous organic cationic dyes such as brilliant green (BG) and rhodamine B (RhB) under sunlight. It was observed from the study that BG (96%, 110 min) and RhB (93%,90 min) show responsive degradation in the presence of α-FeOOH nanorods. Besides this, 99% (100 min) and 99.4% (80 min) BG and RhB get degraded using α-Fe2O3 nanoparticles, respectively. Overall, α-Fe2O3 nanoparticles were a more prominent photocatalyst for the degradation of BG and RhB than α-FeOOH nanorods. [ABSTRACT FROM AUTHOR]

Environmental problems can potentially be solved by covalent organic frameworks (COFs) that contain predesigned porous architectures. Herein, we developed an amorphous tetrazine–triazine-functionalized covalent organic framework (TzTPT-COF) by performing one-pot polycondensations of 2,4,6-tris-(4-formylphenoxy)-1,3,5-triazine (TPT-CHO) and s-tetrazine-diamine (Tz). The TzTPT-COF possesses ordered-disordered accessible nano-channels with an experimental pore width of 8.5 nm and simulated pore width of 6.4 nm. We detail the characterization of two-dimensional TzTPT-COF with readily accessible 8.5 nm-sized pores, which was subsequently employed as a porous adsorbent for the static and dynamic adsorption of small dye molecules, especially methylene blue from dye-adulterated water. Additionally, the COF quickly attained up to 99% of its maximum adsorption capacity within 15 min. The thermal stability of the COF was maintained, with the onset of gradual weight loss observed at 280 °C. Furthermore, the COF exhibited no crystallinity and possesses a mesoporous structure. The experimental findings and in silico simulation revealed that to create COF-based adsorbents with effective dye adsorption capabilities, it is necessary to concurrently consider the inherent pore size of the COF material as well as the size of the organic dye molecules. The TzTPT-COF has a great deal of potential as an adsorbent material for eliminating cationic dyes and other organic pollutants from wastewater due to the high adsorption efficiencies, ultrafast kinetics, and outstanding reusability. Hence, the present findings suggest that COFs can also be proven to be highly versatile porous materials for various environmental remediation applications. [ABSTRACT FROM AUTHOR]

Photochemical functionalization of alkoxyoxazoles with trimethylsilyl azide and N,N-dimethylanilines is described. These C–N bond forming reactions proceed with concomitant oxidative ring-opening assisted by organic dyes as photocatalyst and molecular oxygen, providing access to novel chemical space. Unusual demethylative C–N bond formation in the case of N,N-dimethylanilines establishes a new reactivity pattern for these precursors. [ABSTRACT FROM AUTHOR]

Brightness is a fundamental property of fluorescent nanomaterials reflecting their capacity to absorb and emit light. In sensing materials, brightness is crucial for high-sensitivity (bio)molecular detection, while in optical bioimaging it ensures high spatial and temporal resolution. Fluorescent organic nanoparticles (NPs) are particularly attractive because of their superior brightness compared to organic dyes. With the ever-growing diversity of organic nanomaterials, it is important to establish universal principles for measuring and estimating their brightness. This tutorial review provides definitions of brightness and describes the major approaches to its analysis based on ensemble and single-particle techniques. We present the current chemical approaches to fight Aggregation-Caused Quenching (ACQ) of fluorophores, which is a major challenge in the design of bright organic nanomaterials. The main classes of fluorescent organic NPs are described, including conjugated polymer NPs, aggregation-induced emission NPs, and NPs based on neutral and ionic dyes. Their brightness and other properties are systematically compared. Some brightest examples of bulk solid-state emissive organic materials are also mentioned. Finally, we analyse the importance of brightness and other particle properties in biological applications, such as bioimaging and biosensing. This tutorial will provide guidelines for chemists on the design of fluorescent organic NPs with improved performance and help them to estimate and compare the brightness of new nanomaterials with literature reports. Moreover, it will help biologists to select appropriate materials for sensing and imaging applications. [ABSTRACT FROM AUTHOR]

Sensitizing titanium dioxide (TiO2) with dye molecules offers a cost-effective and environmentally friendly strategy for creating powerful photocatalysts for hydrogen production by reducing the band gap and enhancing sunlight absorption. Despite the challenges of identifying a stable dye with high light harvesting efficiency and effective charge recombination, we present a 1,8-naphthalimide derivative-sensitized TiO2 that achieves ultra-efficient photocatalytic hydrogen production (10.615 mmol g−1 h−1) and maintains activity after 30 hours of cycling. Our research offers valuable insights for designing optimized organic dye-sensitized photocatalysts, advancing clean and sustainable energy solutions. [ABSTRACT FROM AUTHOR]

A set of ullazine-derived D–π–A–π–A photosensitisers were considered and selected for a potential dye with the best performance via computational approaches. The designed dyes HJ1–HJ13, which originated from dye YZ7, were constructed with different π-linking motifs and two kinds of auxiliary withdrawing groups. The photoelectric and photovoltaic parameters were determined by density functional theory approaches, and PBE0 optimisation with the TD-cam-B3LYP method was shown to be the best choice of functional in these designed dyes, with the calculated maximum absorption wavelength and excited lifetime in accordance with the experimental findings for YZ7. Replacement of the C≡C bond by the C＝C bond could reduce aggregation and improve the photoelectronic property. In addition, the D–π–A–π–A-type photosensitiser was found to achieve higher light-harvesting efficiency and higher performance for dye-sensitised solar cells (DSSCs). HJ8 was selected as the potential dye for DSSCs, as it had a 69 nm redshift in the maximum absorption wavelength and a 66% increment in the maximum extinction coefficient compared to YZ7, and achieved 99.9% light-harvesting efficiency, the longest excited time of 2.82 ns, a suitable driving force of injection and regeneration, the largest short-circuit current density and the largest open-circuit voltage. Our theoretical results provide strong guidance for discovering new efficient D–π–A–π–A-type organic dyes in DSSCs. [ABSTRACT FROM AUTHOR]

TiO2 photoelectrodes modified with organic dyes with pyridine anchoring groups are prepared, which are used as photoanodes of dye-sensitized photoelectrochemical cells for efficient water reduction with high photocurrent density and stability in aqueous solutions. Vigorous H2 generation with a production rate of around 250 μmol h−1 is realized with a photoanode of an active area of 5 × 5 cm2. [ABSTRACT FROM AUTHOR]

The slow kinetics of the Co3+/Co2+ catalytic redox cycle on the surface of Co-based solid catalysts greatly limits their application in sulfate radical-based advanced oxidation processes. To overcome this challenge, nanoparticle-assembled rod-like S-doped Co3O4 (S-Co3O4) with abundant oxygen vacancies (OVs) and a mesoporous structure was prepared to activate peroxymonosulfate to degrade various organic dye contaminants. The abundant OVs and good charge transfer capability of S-Co3O4 accelerated the Co3+/Co2+ redox cycle due to the incorporation of S atoms, which improved the Co2+ recovery. The S-Co3O4 catalysts exhibited excellent catalytic activities, and the methylene blue (MB) degradation rate reached 100% within 6 min. The degradation rate constant of the catalytic reaction for the S-Co3O4 + PMS system (0.78 min−1) was 30 times higher than that of the Co3O4 + PMS system (0.026 min−1), which may be due to the synergy between the high Co2+ content, abundant OVs, and large surface area. After six consecutive cycles, the MB degradation efficiency still reached 94.5%, and the cobalt leaching of S-Co3O4 was only 0.42 mg L−1. In the S-Co3O4-activated PMS system, SO4˙− and 1O2 were the main active species, but 1O2 played the main role in contaminant degradation. This study provides a novel method for accelerating Co3+/Co2+ circulation and reducing Co ion leaching from the surface of heterogeneous Co-based catalysts to substantially enhance their performance. [ABSTRACT FROM AUTHOR]

Organic room-temperature phosphorescence (RTP) materials are currently the focus of research in the field of bioimaging. In comparison with the conventional imaging modalities based on organic fluorescent dyes, RTP materials with long lifetime enable time-resolved imaging to improve the imaging resolution by avoiding autofluorescence. In this review, we will start with summarizing strategies for achieving high performance RTP materials for bioimaging, including the development of RTP-compounds, host–guest doping materials, and supramolecular assemblies. We then discuss the optimization of nanonization processes to obtain RTP nanoparticles with controllable size, high dispersibility, and improved stability. The differences between top-down and bottom-up approaches are further described. Finally, we briefly introduce the emerging methods for preparing RTP materials for bioimaging. [ABSTRACT FROM AUTHOR]

We report the synthesis and characterisation of [2]rotaxanes based on a stilbazolium dye and a calix[6]arene macrocycle. Since both components are non-symmetric, two orientational isomers are obtained. The two isomers display distinct photophysical and photochemical properties in solution and solid state, superior to the unencapsulated dye. [ABSTRACT FROM AUTHOR]

In this study, we have synthesized a facile tyrosine derivative based compound (2-QY), which can act both as a gelator and a reducing agent. 2-QY can assemble to form a functional metallohydrogel (2-QY-Au) in the presence of HAuCl4 under mild conditions (room temperature, aqueous solution, and simple sonication treatment). Au nanoparticles (Au NPs) can be in situ formed and dispersed uniformly in the gel system, which did not require an external reducing agent and a stabilizing agent. The obtained 2-QY-Au NP@metallohydrogel can be used as a catalyst to degrade a variety of dyes, such as methyl orange, methyl green, reactive black 5, reactive orange 16, and p-nitrophenol. In particular, it exhibits excellent catalytic activity towards degradation of methylene blue in the presence of NaBH4, with a kapp value (13.23 ± 0.21 s−1) higher than those of most of the reported catalysts in the literature. Moreover, 2-QY-Au NPs have good biocompatibility and exhibit antibacterial activity against E. coli and B. subtilis. Therefore, the 2-QY-Au NP@metallohydrogel could be used as an effective catalyst for the degradation of pollution containing organic dyes, as well as for potential applications in the biomedical field. [ABSTRACT FROM AUTHOR]

In this work, two defective zirconium-based metal–organic frameworks (Zr-MOFs), MOF-808-OH and MOF-808-NH2, were synthesized by partially replacing the 1,3,5-benzenetricarboxylate building block with 5-hydroxyisophthalate and 5-aminoisophthalate, respectively. The structural features of the defective materials were analyzed by powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), nitrogen physisorption at 77 K, and thermogravimetric analysis (TGA). Importantly, the number of defect sites determined via proton nuclear magnetic resonance (1H-NMR) analysis of the digested materials was approximately 7 mol% for MOF-808-OH and 3 mol% for MOF-808-NH2. The presence of the defect sites increased the number of acidic centers on Zr-clusters originating from missing-linker nodes which accounted for a remarkable adsorption capacity towards various anionic organic dyes and chromium (VI) species. Compared to standard MOF-808, the defect-engineered ones showed significant increments by 30–60% in trapping capacity for anionic contaminants including sunset yellow, quinoline yellow, methyl orange, and potassium dichromate, while they exhibited modest improvements by 5–15% in the removal of cationic dyes, namely malachite green and methylene blue. [ABSTRACT FROM AUTHOR]

One-pot co-precipitation of target molecules e.g. organic dyes and the synthesis of a crystal containing microporous–mesoporous regimes of zeolitic imidazolate frameworks-8 (ZIF-8) are reported. The synthesis method can be used for cationic (rhodamine B (RhB), methylene blue (MB)), and anionic (methyl blue (MeB)) dyes. The crystal growth of the ZIF-8 crystals takes place via an intermediate phase of zinc hydroxyl nitrate (Zn5(OH)8(NO3)2) nanosheets that enabled the adsorption of the target molecules i.e., RhB, MB, and MeB into their layers. The dye molecules play a role during crystal formation. The successful encapsulation of the dye molecules was proved via diffuse reflectance spectroscopy (DRS) and electrochemical measurements e.g., cyclic voltammetry (CV), linear sweep voltammetry (LSV), and electrochemical impedance spectroscopy (EIS). The materials were investigated for carbon dioxide (CO2) adsorption and adenosine triphosphate (ATP) biosensing. ZIF-8, RhB@ZIF-8, MB@ZIF-8, and MeB@ZIF-8 offered CO2 adsorption capacities of 0.80, 0.84, 0.85, and 0.53 mmol g−1, respectively. The encapsulated cationic molecules improved the adsorption performance compared to anionic molecules inside the crystal. The materials were also tested as a fluorescent probe for ATP biosensing. The simple synthesis procedure offered new materials with tunable surface properties and the potential for multi-functional applications. [ABSTRACT FROM AUTHOR]

In this work, N-doped BiOBr nanosheets were successfully prepared by using a novel high-shear mixer to facilitate uniform dispersion followed by a facile hydrothermal method, to evaluate the effects of N incorporation in BiOBr on photocatalytic performance of the as-prepared semiconductor catalysts for degrading organic contaminants. A significant facilitating effect was observed where the as-obtained N-doped BiOBr photocatalysts showed optimal photoreactivity for degrading organic wastewater compared to the undoped BiOBr when N atoms were uniformly incorporated into the BiOBr framework. In particular, 0.9N-BiOBr exhibited the top-flight performance for photocatalytic degradation of RhB, which was 15.3 times higher than the undoped BiOBr under visible-light irradiation (λ > 420 nm). Moreover, more crucial photogenerated active species for the photocatalytic degradation of RhB under visible-light irradiation, including superoxide radicals (O2˙−) and photoinduced holes (h+) were obtained, which resulted in a significant increase in the photoreactivity and stability of 0.9N-BiOBr. Through a range of characterizations such as SEM, TEM, XRD, XPS, EIS and so on, the physicochemical structural properties of the as-prepared photocatalysts were investigated and revealed in detail. This work demonstrates that N doping in BiOBr can functionalize as an efficient regulator for BiOBr-based photocatalysts to enhance the photodegradation performance of organic contaminants such as organic dyes in an aquatic environment, and the results obtained in this work may provide insight into the design of general non-metallic doping strategies for potentially efficient and inexpensive photocatalysts. [ABSTRACT FROM AUTHOR]

There has been rapid development of organic–inorganic perovskite solar cells (PSCs) in recent years, but efficiency and stability challenges remain due to the massive defects in perovskite films. Here, the organic dye Th-azi-Pyr (ethyl 2-(2-(3-methyl-5-oxo-1-phenyl-1,5-dihydro-4H-pyrazol-4-ylidene) hydrazineyl)-4,5,6,7-tetrahydrobenzo[b]thiophene-3-carboxylate) with carbonyl, pyrazolone structure, and benzene ring was synthesized and used to prepare high-quality perovskite film as an additive. Th-azi-Pyr formed relatively stable intermediate ligands with uncoordinated Pb and I, slowing the crystal growth and reducing the grain boundary defects of perovskite. In addition, the benzene ring in the dye protected against moisture and increased the stability of the perovskite film. Therefore, the Th-azi-Pyr-modified PSC assembled in an air environment exhibited a promising power conversion efficiency (PCE) of 19.27%, which is superior to the 15.33% of the control PSC. Additionally, 88% of the original performance was maintained after 300 h at 25 ± 5 °C and 50 ± 10% relative humidity, implying that the modified PSCs exhibited greater stability than the untreated PSCs. This work indicates that simple and low-cost organic dyes are excellent defect passivators for high-performance PSCs. [ABSTRACT FROM AUTHOR]

We demonstrate a low-cost, simple-operation, and environmentally friendly magnetic grinding synthetic process to prepare nontoxic copper sulfide-based composites with photocatalytic activity. Using this efficient approach, CuS/ZnS and CuS/CdS composites were successfully synthesized from elemental powders without using any other additives or solvents. The formation of metal sulfides was confirmed using a series of characterizations. The photocatalytic activities of the as-prepared materials were evaluated by the degradation of methylene blue (MB), rhodamine B (RhB), and methyl orange (MO) dyes in the presence of hydrogen peroxide (H2O2), which served as an oxidant under visible irradiation. The degradation efficiencies of MB and RhB by CuS/ZnS and CuS/CdS composites were more than 95% in 30 min and the degradation efficiency of MO was more than 85% in 90 min. The photocatalytic activities of the CuS/ZnS and CuS/CdS composites were better than those of pure metal sulfides. In addition, the CuS/ZnS and CuS/CdS composites showed good stability toward photocatalytic degradation and their main reactive species for degrading organic dyes are photogenerated hydroxyl radical (˙OH). Reasonable photocatalytic reaction mechanisms are proposed to explain the photocatalytic processes of the CuS/ZnS and CuS/CdS composites. [ABSTRACT FROM AUTHOR]

Covalent organic frameworks (COFs) are efficient semiconductor materials with superior catalytic activity and adjustable band gaps for the efficient degradation of organic pollutants in water. However, the synthetic yield of COF is generally small and only exists in the laboratory stage. In this paper, we introduced an emulsifier-mediated strategy into the synthesis of a COF for the first time and synthesized a COF with higher crystallinity and a higher synthetic yield of 84.7%. The specific surface area of BJH was also increased from 388.7 m2 g−1 to 1678.5 m2 g−1 and the photocatalytic degradation efficacy of 10 ppm methylene blue was increased from 26% to 100% within 50 min. This work provides a promising strategy to achieve a COF with a higher surface area, synthetic yield and photocatalytic efficacy via the emulsifier-mediated strategy, which would promote the industrial and practical production of COFs. [ABSTRACT FROM AUTHOR]

Nowadays, selective removal of cationic or anionic organic dyes from aqueous solution has become a new research focus. Meanwhile, metal–organic framework materials have attracted extensive attention in the field of wastewater treatment due to their porous structures. From this perspective, based on pyridine–imidazole heterocyclic ligand 2,4,5-tri(4-pyridine)-1H-imidazole (Htpim), two new complexes Ni(Htpim)2Cl2·2H2O (1) and Co(Htpim)2(OH)Cl·7H2O (2) were firstly designed and synthesized by the solvothermal method under 100 °C condition. Meanwhile, complexes 1 and 2 were characterized by various microanalyses. Also, the crystal structures of complexes 1 and 2 were determined by single-crystal X-ray diffraction. The results indicated that the three-dimensional supramolecular structures of both complexes 1 and 2 were connected by π–π interactions. To explore their functional properties, the adsorption capacities of complexes 1 and 2 for organic dyes were investigated in water. The experimental results exhibited that complexes 1 and 2 had better selective adsorption toward eosin dye with negative charges. According to the Langmuir, Freundlich and Temkin isotherm models, it was found that the Langmuir isotherm was more consistent with the adsorption process of complexes 1 and 2, and the adsorption capacities of complexes 1 and 2 for eosin were 125 mg g−1 and 71.43 mg g−1, respectively. According to thermodynamic analysis, the adsorption process of complexes 1 and 2 was spontaneous. Meanwhile, it was found that the pH of the dye solution also had an influence on the adsorption process. Also, adsorption kinetic curve fitting showed that complexes 1 and 2 both conformed to pseudo-second-order curves. In addition, the possible adsorption mechanisms were explored. [ABSTRACT FROM AUTHOR]