Highly Luminescent Eu3+-Incorporated Zr-MOFs as Fluorescence Sensors for Detection of Hazardous Organic Compounds in Water and Fruit Samples.

Considering the risk of toxic organic compounds to both human health and the environment, highly luminescent Eu3+-incorporated amino-functionalized zirconium metal-organic frameworks, namely, Eu/MOF and Eu@MOF were synthesized via the solvothermal method. The synthesized luminescent europium-incorporated MOFs act as outstanding sensor materials for diphenylamine and dinitrobenzene detection in water and fruit samples. The synergistic effect of Eu3+ metal ions and amino-functionalized MOFs enhances the luminescent properties of the MOFs improving the fluorescence sensing ability toward the analytes. The enhancement in the detection capacity of the Eu3+-incorporated sensors than the sole MOF toward toxic organic compounds was confirmed using the Stern-Volmer equation of limit of detection (LOD) measurements along with fluorescence lifetime measurements. The sensors exhibited turn-on fluorometric detection toward their respective analytes due to the inner filter effect. The plausible fluorescence sensing mechanism has been studied. The DFT calculations have been integrated to study the structure, stability, and charge transfer processes.

Highly efficient visible-light induced N-doped ZnO@g-C3N4 and S-doped ZnO@g-C3N4 photocatalysts for environmental remediation.

Facile, cost-effective and eco-friendly synthesis of N-doped ZnO@g-C3N4 and S-doped ZnO@g-C3N4 photocatalysts towards efficient degradation of environmental pollutants was achieved. The as-synthesized 2 wt% N-doped ZnO@g-C3N4 and 2 wt% S-doped ZnO@g-C3N4 achieved 96.2% and 90.4% degradation efficiencies towards crystal violet (100 ppm) within 45 min irradiation and 99.3% and 92.3% photocatalytic degradation efficiencies towards brilliant green (100 ppm) dye within 30 min irradiation, respectively, under a normal 90 W LED light instead of an expensive commercial light source. Moreover, the N-doped ZnO@g-C3N4 and S-doped ZnO@g-C3N4 nanocomposites showed excellent stability in the photodegradation of crystal violet and brilliant green dyes. The modification made on ZnO by doping with nitrogen and sulphur enhances the visible-light absorption as well as the separation of photoexcited charge carriers. The active radicals ˙OH and ˙O2- are both identified to play important roles in the photodegradation of crystal violet and brilliant green.

ChatGPT in the Material Design: Selected Case Studies to Assess the Potential of ChatGPT.

The pursuit of designing smart and functional materials is of paramount importance across various domains, such as material science, engineering, chemical technology, electronics, biomedicine, energy, and numerous others. Consequently, researchers are actively involved in the development of innovative models and strategies for material design. Recent advancements in analytical tools, experimentation, and computer technology additionally enhance the material design possibilities. Notably, data-driven techniques like artificial intelligence and machine learning have achieved substantial progress in exploring various applications within material science. One such approach, ChatGPT, a large language model, holds transformative potential for addressing complex queries. In this article, we explore ChatGPT's understanding of material science by assigning some simple tasks across various subareas of computational material science. The findings indicate that while ChatGPT may make some minor errors in accomplishing general tasks, it demonstrates the capability to learn and adapt through human interactions. However, issues like output consistency, probable hidden errors, and ethical consequences should be addressed.

Controlled Ni doping on a g-C3N4/CuWO4 photocatalyst for improved hydrogen evolution.

The development of a low-cost, environment-friendly and suitable semiconductor-based heterogeneous photocatalyst poses a great challenge towards extremely competent and substantial hydrogen evolution. A series of environment-friendly and proficient S-scheme Ni-doped CuWO4 nanocrystals supported on g-C3N4 nanocomposites (Ni-CuWO4/g-C3N4) were constructed to ameliorate the photocatalytic efficacy of pure g-C3N4 and Ni-CuWO4 and their activity in H2 generation through photocatalytic water splitting was evaluated. The Ni-CuWO4 nanoparticles were synthesized through doping of Ni2+ on wolframite CuWO4 crystals via the chemical precipitation method. An elevated hydrogen generation rate of 1980 µmol h-1 g-1 was accomplished over the 0.2Ni-CuWO4/g-C3N4 (0.2NCWCN) nanocomposite with an apparent quantum yield (AQY) of 6.49% upon visible light illumination (λ ≥ 420 nm), which is evidently 7.1 and 17.2 fold higher than those produced from pristine g-C3N4 and Ni-CuWO4. The substantial enhancement in the photocatalytic behaviour is primarily because of the large surface area, limited band gap energy of the semiconductor composite and magnified light harvesting capability towards visible light through the inclusion of g-C3N4, thus diminishing the reassembly rate of photoinduced excitons. Further, density functional theory (DFT) calculations were performed to investigate the structural, electronic and optical properties of the composite. Theoretical results confirmed that the Ni-CuWO4/g-C3N4 composite is a potential candidate for visible-light-driven photocatalysts and corroborated with the experimental findings. This research provides a meaningful and appealing perspective on developing cost-effective and very proficient two-dimensional (2D) g-C3N4-based materials for photocatalytic H2 production to accelerate the separation and transmission process of radiative charge carriers.

Multifunctional CdS Nanoparticle-Decorated CeO2 as Efficient Visible Light Photocatalysts and Toxic Cr(VI) Sensors.

Several one-dimensional and three-dimensional CdS@CeO2 nanocomposites were synthesized by a solvothermal route. A nanoflower-shaped CdS@CeO2 nanocomposite (CdS-NF@CeO2) was selected as the model catalyst after various characterizations. It was, then, employed directly as a luminescent sensor for Cr(VI) detection in an aqueous medium. A good linear quenching was observed in the range of 0-0.5 µM with a detection limit of 0.04 µM. The quantum yield of the catalyst was found to be 73%. Moreover, our catalyst is highly selective toward Cr(VI) and can be applied as an efficient sensor for real water analysis. The efficiency of the catalyst was also tested in controlling the photocatalytic activity for oxidation of benzylamine to N-benzylidenebenzylamine under a domestic LED bulb with molecular O2 as a sole, green oxidant. Conversion (>99.9%) and selectivity as high as 100% were observed for the CdS-NF@CeO2 photocatalyst. These results show the potential applications of CdS-NF@CeO2 nanocomposites as an efficient photocatalyst for organic transformation and environmental remediation.

Visible-light driven reaction of CO2 with alcohols using a Ag/CeO2 nanocomposite: first photochemical synthesis of linear carbonates under mild conditions.

The first photochemical synthesis of linear carbonates from the reaction of CO2 with alcohols using a silver-doped ceria nanocomposite at room temperature under visible light irradiation is described. DFT calculations suggested the electron transfer from Ag 4d states to Ce 4f states in the composite for the photoreaction.

Visible Light-Active Ternary Heterojunction Photocatalyst for Efficient CO2 Reduction with Simultaneous Amine Oxidation and Sustainable H2O2 Production.

The present work described a unique approach for CO2 reduction to methanol along with the oxidation of various amines to the corresponding imines and photocatalytic H2O2 production from H2O and molecular O2 using a heterojunction photocatalyst made up of ZnIn2S4/Ni12P5/g-C3N4(NCZ) under visible light irradiation. The photocatalysts were synthesized via a high-temperature treatment of nickel and phosphorous precursors with g-C3N4 followed by decoration of ZnIn2S4. The synthesized photocatalysts were characterized using various spectroscopic and microscopic techniques. The density functional theory (DFT) studies suggested the participation of the valence band maximum (VBM) from Ni12P5 and the conduction band maximum (CBM) from ZnIn2S4 in the ternary NCZ heterojunction. The ternary composite exhibited superior photocatalytic activity compared to that of its individual components due to the formation of a heterojunction, thereby enhancing the transfer efficiency of electrons from the conduction band of g-C3N4 to that of ZnIn2S4 using Ni12P5 as an electron bridge. Moreover, the reduced band gap of the ternary heterojunction played a key role in its higher efficiency.

Functional groups assisted-photoinduced electron transfer-mediated highly fluorescent metal-organic framework quantum dot composite for selective detection of mercury (II) in water.

The presence of toxic mercury (II) in water is an ever-growing problem on earth that has various harmful effect on human health and aquatic living organisms. Therefore, detection of mercury (II) in water is very much crucial and several researches are going on in this topic. Metal-organic frameworks (MOFs) are considered as an effective device for sensing of toxic heavy metal ions in water. The tunable functionalities with large surface area of highly semiconducting MOFs enhance its activity towards fluorescence sensing. In this study, we are reporting one highly selective and sensitive luminescent sensor for the detection of mercury (II) in water. A series of binary MOF composites were synthesized using in-situ solvothermal synthetic technique for fluorescence sensing of Hg2+ in water. The well-distributed graphitic carbon nitride quantum dots on porous zirconium-based MOF improve Hg2+ sensing activity in water owing to their great electronic and optical properties. The binary MOF composite (2) i.e., the sensor exhibited excellent limit of detection (LOD) value of 2.4 nmol/L for Hg2+. The sensor also exhibited excellent performance for mercury (II) detection in real water samples. The characterizations of the synthesized materials were done using various spectroscopic techniques and the fluorescence sensing mechanism was studied.

Mesoporous SBA-15 supported gold nanoparticles for solvent-free oxidation of cyclohexane: superior catalytic activity with higher cyclohexanone selectivity.

Surface modification of mesoporous SBA-15 with (3-mercaptopropyl) trimethoxysilane greatly enhances its capability to adsorb the tetrachloroauric anion (AuCl4-). The calcination of the sample after the adsorption experiment led to the generation of homogeneously dispersed, spherical, single crystalline gold nanoparticles (Au0 NPs) of less than 5 nm size, embedded on SBA-15 as observed from the TEM images. The as-prepared SBA-15/Au0 nanohybrid material has offered excellent catalytic activity for the selective oxidation of cyclohexane using TBHP as the oxidant in the absence of any solvent. A maximum of 48.7% cyclohexane conversion was achieved and surprisingly, cyclohexanone (K) has much higher selectivity (>95%) than cyclohexanol (A). The hot-filtration study confirmed the leach-resistant characteristics as well as the true heterogeneous catalytic activity of the SBA-15/Au0 nanohybrid catalyst. The catalyst was recycled up to four times without significant loss in its catalytic activity.

Regioselective Friedel-Crafts Acylation Reaction Using Single Crystalline and Ultrathin Nanosheet Assembly of Scrutinyite-SnO2.

Peculiar physicochemical properties of two-dimensional (2D) nanomaterials have attracted research interest in developing new synthetic technology and exploring their potential applications in the field of catalysis. Moreover, ultrathin metal oxide nanosheets with atomic thickness exhibit abnormal surficial properties because of the unique 2D confinement effect. In this work, we present a facile and general approach for the synthesis of single crystalline and ultrathin 2D nanosheets assembly of scrutinyite-SnO2 through a simple solvothermal method. The structural and compositional characterization using X-ray diffraction (Rietveld refinement analysis), high-resolution transmission electron microscopy, atomic force microscopy, X-ray photoelectron spectroscopy, and so on reveal that the as-synthesized 2D nanosheets are ultrathin and single crystallized in the scrutinyite-SnO2 phase with high purity. The ultrathin SnO2 nanosheets show predominant growth in the [011] direction on the main surface having a thickness of ca. 1.3 nm. The SnO2 nanosheets are further employed for the regioselective Friedel-Crafts acylation to synthesize aromatic ketones that have potential significance in chemical industry as synthetic intermediates of pharmaceuticals and fine chemicals. A series of aromatic substrates acylated over the SnO2 nanosheets have afforded the corresponding aromatic ketones with up to 92% yield under solvent-free conditions. Comprehensive catalytic investigations display the SnO2 nanosheet assembly as a better catalytic material compared to the heterogeneous metal oxide catalysts used so far in the view of its activity and reusability in solvent-free reaction conditions.

Metal-organic frameworks and their composites for fuel and chemical production via CO2 conversion and water splitting.

Increase in the global energy demand has been leading to major energy crises in recent years. The use of excess fossil fuels for energy production is causing severe global warming, as well as energy shortage. To overcome the global energy crisis, the design of various chemical structures as efficient models for the generation of renewable energy fuels is very much crucial, and will limit the use of fossil fuels. Current challenges involve the design of Metal-Organic Framework (MOF) materials for this purpose to diminish the energy shortage. The large surface area, tunable pore environment, unique structural property and semiconducting nature of the highly porous MOF materials enhance their potential applications towards the production of enhanced energy fuels. This review is focused on the architecture of MOFs and their composites for fuels and essential chemicals production like hydrogen, methane, ethanol, methanol, acetic acid, and carbon monoxide, which can be used as renewable fuel energy sources to limit the use of fossil fuels, thereby reducing global warming.

Correction: A ferrocene functionalized Schiff base containing Cu(II) complex: synthesis, characterization and parts-per-million level catalysis for azide alkyne cycloaddition.

Correction for 'A ferrocene functionalized Schiff base containing Cu(ii) complex: synthesis, characterization and parts-per-million level catalysis for azide alkyne cycloaddition' by Firdaus Rahaman Gayen et al., Dalton Trans., 2020, 49, 6578-6586, DOI: 10.1039/d0dt00915f.

Endorsing Organic Porous Polymers in Regioselective and Unusual Oxidative C═C Bond Cleavage of Styrenes into Aldehydes and Anaerobic Benzyl Alcohol Oxidation via Hydride Elimination.

Oxidative cleavage of styrene C═C double bond is accomplished by employing a nitrogen-rich triazine-based microporous organic polymer as an organocatalyst. We report this regioselective reaction as first of its kind with no metal add-ons to afford benzaldehydes up to 92% selectivity via an unusual Wacker-type C═C bond cleavage. Such a reaction pathway is generally observed in the presence of a metal catalyst. This polymer further shows high catalytic efficiency in an anaerobic oxidation reaction of benzyl alcohols into benzaldehydes. The reaction is mediated by a base via the in situ generation of hydride ions. This study is supported by experiments and computational analyses for a free-radical transformation reaction of oxidative C═C bond cleavage of styrenes and a hydride elimination mechanism for the anaerobic oxidation reaction. Essentially, the study unveils protruding applications of metal-free nitrogen-rich porous polymers in organic transformation reactions.

Stable lead-halide perovskite quantum dots as efficient visible light photocatalysts for organic transformations.

Lead halide perovskite (LHP) based colloidal quantum dots (CQDs) have tremendous potential for photocatalysis due to their exceptional optical properties. However, their applicability in catalysis is restricted due to poor chemical stability and low recyclability. We report halide-passivated, monodisperse CsPbBr3CQDs as a stable and efficient visible-light photocatalyst for organic transformations. We demonstrate oxidative aromatization of a wide range of heterocyclic substrates including examples which are poor hydrogen transfer (HAT) reagents. Two to five-fold higher rate kinetics were observed for reactions catalyzed by CsPbBr3CQDs in comparison with bulk-type CsPbBr3 (PNCs) or conventionally synthesized CsPbBr3CQDs and other metal organic dyes (rhodamine 6G and [Ru(bpy)3]2+). Furthermore, these CQDs exhibit improved air-tolerance and photostability and in turn show a higher turnover number (TON) of 200, compared to conventionally prepared CQDs (TON = 166) and state-of-the-art bulk-type perovskite-based catalyst (TON = 177). Our study paves the way for the practical applicability of energy-level tunable, size-controlled LHP CQDs as efficient photocatalysts in organic synthesis.

Tunable NIR-II emitting silver chalcogenide quantum dots using thio/selenourea precursors: preparation of an MRI/NIR-II multimodal imaging agent.

Aqueous-stable, Cd- and Pb-free colloidal quantum dots with fluorescence properties in the second near-infrared region (NIR-II, 1000-1400) are highly desirable for non-invasive deep-tissue optical imaging and biosensing. The low band-gap semiconductor, silver chalcogenide, offers a non-toxic and stable alternative to existing Pd, As, Hg and Cd-based NIR-II colloidal quantum dots (QDs). We report facile access to NIR-II emission windows with Ag2X (X = S, Se) QDs using easy-to-prepare thio/selenourea precursors and their analogues. The aqueous phase transfer of these QDs with a high conservation of fluorescence quantum yield (retention up to ∼90%) and colloidal stability is demonstrated. A bimodal NIR-II/MRI contrast agent with a tunable fluorescence and high T1 relaxivity of 408 mM-1 s-1 per QD (size ∼ 2.2 nm) and 990 mM-1 s-1 per QD (size ∼ 4.2 nm) has been prepared by grafting 50 and 120 monoaqua Gd(iii) complexes respectively to two differently sized Ag2S QDs. The size of the nanocrystals is crucial for tuning the Gd payload and the relaxivity.

A ferrocene functionalized Schiff base containing Cu(ii) complex: synthesis, characterization and parts-per-million level catalysis for azide alkyne cycloaddition.

Atom economy is one of the major factors in developing catalysis chemistry. Using the minimum amount of catalyst to obtain the maximum product yield is of the utmost priority in catalysis, which drives us to use parts-per-million (ppm) levels of catalyst loadings in syntheses. In this context, a new ferrocene functionalized Schiff base and its copper(ii) complex have been synthesized and characterized. This Cu(ii) complex is employed as a catalyst for popular 'click chemistry', where 1,2,3-triazoles are the end product. As low as 5 ppm catalyst loading is enough to produce gram scale product, and highest turnover number (TON) and turnover frequency (TOF) values of 140 000 and 70 000 h-1 are achieved, respectively. Furthermore, this highly efficient protocol has been successfully applied to the preparation of diverse functionalized materials with pharmaceutical, labelling and supramolecular properties.

Pd-NiO-Y/CNT nanofoam: a zeolite-carbon nanotube conjugate exhibiting high durability in methanol oxidation.

A Pd-NiO-based catalyst hybridized with zeolite-Y and multiwalled carbon nanotubes has been found to show a remarkable mass activity in the electrochemical oxidation of methanol with long term durability up to 80 000 s.