Single-step Solution Research Articles

One-step solution processing of printable Sb2S3 nano-rods for high-performance photoconductors

Abstract Achieving large-scale, affordable, and highly dependable production of antimony sulfide is crucial for unlocking its potential in various applications, including photoconductors, solid-state batteries, thermoelectrics, and solar cells. In our study, we introduce a straightforward, economical, and catalyst-free single-step solution process for fabricating one-dimensional Sb2S3 nanostructures on flexible polyimide substrates, and we explore their use as photoconductors in the ultraviolet (UV) and visible light spectrum. The precursor solution for creating the Sb2S3 films is prepared by dissolving specified quantities of elemental Sb and S in a solution mixture of ethylenediamine and 2-mercaptoethanol. This solution is then spin-coated onto a polyimide substrate and subsequently annealed at 300 °C for several minutes. Utilizing field emission scanning electron microscopy, grazing incidence x-ray diffraction, Raman spectroscopy, and transmission electron microscopy, we demonstrate that the Sb2S3 films possess high crystallinity, uniform morphology, and a composition that is nearly stoichiometric. Additionally, through Tauc plot analysis, we determine that the films exhibit a direct bandgap of approximately 1.67 eV, which is in close agreement with the bandgap predicted by Heyd–Scuseria–Ernzerhof (HSE06) density-functional theory simulations. The metal-semiconductor–metal photoconductors fabricated with these films display a significant photoresponse to both UV and visible light. These devices achieve a UV on/off ratio of up to 160 at a light intensity of 30 mW cm−2, with brief rise and fall times of 44 ms and 28 ms, respectively.

A weighted stabilized lagrange interpolation collocation method for boundary condition identification in 3D electromagnetic inverse scattering

The identification of boundary conditions in electromagnetic inverse scattering is of importance in various engineering applications, ranging from geophysical exploration to wireless communication. Conventional numerical methods solving this problem often suffer from the iterative process, leading to inefficiencies and non-convergence. This paper introduces a weighted scheme of the stabilized Lagrange interpolation collocation method (weighted SLICM) to resolve this problem. Weighted SLICM efficiently integrates governing equations, boundary conditions, and measurement conditions using a weighted least squares approach, offering a straightforward single-step solution and obviating the need for iterative processes in traditional methods like the finite element method. By incorporating regularization techniques, weighted SLICM decreases measurement errors which are unavoidable in engineering problems, thereby ensuring high efficiency and accuracy. In addition, characterized as a strong-form collocation method that relies solely on point information but not on grid connectivity, the weighted SLICM is readily extendible to complex three-dimensional applications in electromagnetic inverse scattering. Extensive simulations of benchmark problems show its ability to achieve accurate and stable results in boundary condition identification in electromagnetic inverse scattering problems including 1D, 2D, and 3D environments, highlighting the effectiveness of the weighted SLICM in navigating complex engineering challenges and substantially enriching research methodologies in this area.

Single step grown porous polycrystalline nickel microstructures with ultra-thin defect rich surface oxide for alkaline water oxidation

Investigation on the intrinsic catalytic activity of structurally diverse polycrystalline nickel microstructures such as porous nickel sheets (PNS), porous folded/curled nickel structures (PFNS) and porous nickel balls (PNB) revealed the surface bounded electrocatalytic activities within an alkaline reaction environment for water oxidation. Nickel microstructures were grown via template/surfactant-free, single step solution combustion technique in air atmosphere. The distinct morphologies (porous nickel sheets, porous folded/curled nickel structures and porous nickel balls) were achieved through changing the quantity of HNO3 in the reaction mixture. The physicochemical characterisations were done with XRD, FESEM, EDS and XPS. Microscopic studies revealed the growth of nickel grains with numerous macro pores forming microstructures in distinct morphologies. The O ls spectra of XPS studies revealed the presence of O−/O2− sites and Ni 2p spectra were distinguished between the formation of Ni0/Ni2+/Ni3+ states, implied the existence of surface oxide with plenty of defects. The synergistic effect results from the formation of microscopic porous architectures with defect rich surface oxide on the electrochemical behaviour and OER activity of PNS, PFNS and PNB were discussed with electrochemical techniques such as CV, LSV, EIS and CP. The OER kinetics in terms of relatively low value of overpotential at 10 mA cm−2 and Tafel slope along with high specific activity of PNS/GCE with respect to PFNS/GCE and PNB/GCE were attributed to the combined effect of increase in electrochemical surface area, high roughness factor and fast charge transfer kinetics. The better electrochemical performance and OER activities of porous nickel sheets in comparison with folded/curled nickel structures and nickel balls is contributed to the unique 2D porous architecture with plenty of oxygen vacancies. This structure not only expose more surface for the formation of passive oxide layer in an alkaline reaction environment but also exhibit facile charge transport properties, causes the generation of numerous surface-active sites for electrocatalytic water oxidation. The outcome of our work gives new insights on the surface electrochemistry of polycrystalline nickel, enables micro-structuring as a prospective strategy towards the optimization of electrocatalysts as anode material for alkaline water oxidation.

Reduction of surface treatment time by combination of citric acid and ascorbic acid while restoring shear bond strength of metal brackets bonded to bleached enamel: a pilot study

BackgroundTo investigate the effect of a 50% ascorbic acid with 50% citric acid solution on the immediate shear bond strength (SBS) of metallic brackets after tooth bleaching. The enamel etching pattern and the required quantity of these combined acids as antioxidants following 35% hydrogen peroxide (HP) bleaching were also determined.MethodsThe stability of the solution at room temperature was assessed at various time intervals. Fifty teeth were randomly divided into five groups: non-bleached (G1), bleached then acid etched (G2), bleached followed by a 10-minute treatment with 10% sodium ascorbate and acid etched (G3), 5-minute treatment with 50% ascorbic acid (G4), and 5-minute treatment with a combination of 50% ascorbic acid and 50% citric acid (G5). Groups G2, G3, G4 and G5 were bleached by 35% HP gel for a total of 32 min. Acid etching in groups G1, G2, and G3 was performed using 37% phosphoric acid (Ormco®, Orange, CA, USA) for 15 s. In all groups, metal brackets were immediately bonded using Transbond™ XT primer and Transbond™ PLUS adhesive, with light curing for 40 s. The SBS was tested with a universal testing machine, and statistical analysis was conducted using one-way ANOVA followed by Tukey’s HSD test. The level of significance was set at p < 0.05 for all statistical tests.ResultsStability tests demonstrated that the combined acids remained effective for up to 21 days. Group G5 significantly increased the SBS of bleached teeth to the level of G1 (p < 0.05), while G3 did not achieve the same increase in SBS (p > 0.05). SEM analysis revealed enamel etching patterns similar to those of both control groups (G1 and G2). Kinetic studies at 6 min indicated that the antioxidation in G5 reacted 0.2 mmole lower than in G3 and G4.Conclusion5-minute application of the combined acids enhanced the SBS of bleached teeth comparable to unbleached teeth. The combined acids remain stable over two weeks, presenting a time-efficient, single-step solution for antioxidant application and enamel etching in orthodontic bracket bonding.

Assessment of cerebral drug occupancy in humans using a single PET-scan: A [11C]UCB-J PET study

PurposeHere, we evaluate a PET displacement model with a Single-step and Numerical solution in healthy individuals using the synaptic vesicle glycoprotein (SV2A) PET-tracer [11C]UCB-J and the anti-seizure medication levetiracetam (LEV). We aimed to (1) validate the displacement model by comparing the brain LEV-SV2A occupancy from a single PET scan with the occupancy derived from two PET scans and the Lassen plot and (2) determine the plasma LEV concentration-SV2A occupancy curve in healthy individuals.MethodsEleven healthy individuals (five females, mean age 35.5 [range: 25–47] years) underwent two 120-min [11C]UCB-J PET scans where an LEV dose (5–30 mg/kg) was administered intravenously halfway through the first PET scan to partially displace radioligand binding to SV2A. Five individuals were scanned twice on the same day; the remaining six were scanned once on two separate days, receiving two identical LEV doses. Arterial blood samples were acquired to determine the arterial input function and plasma LEV concentrations. Using the displacement model, the SV2A-LEV target engagement was calculated and compared with the Lassen plot method. The resulting data were fitted with a single-site binding model.ResultsSV2A occupancies and VND estimates derived from the displacement model were not significantly different from the Lassen plot (p = 0.55 and 0.13, respectively). The coefficient of variation was 14.6% vs. 17.3% for the Numerical and the Single-step solution in Bland-Altman comparisons with the Lassen plot. The average half maximal inhibitory concentration (IC50), as estimated from the area under the curve of the plasma LEV concentration, was 12.5 µg/mL (95% CI: 5–25) for the Single-Step solution, 11.8 µg/mL (95% CI: 4–25) for the Numerical solution, and 6.3 µg/mL (95% CI: 0.08-21) for the Lassen plot. Constraining Emax to 100% did not significantly improve model fits.ConclusionPlasma LEV concentration vs. SV2A occupancy can be determined in humans using a single PET scan displacement model. The average concentration of the three computed IC50 values ranges between 6.3 and 12.5 µg/mL. The next step is to use the displacement model to evaluate LEV occupancy and corresponding plasma concentrations in relation to treatment efficacy.Clinical trial registrationNCT05450822. Retrospectively registered 5 July 2022 https://clinicaltrials.gov/ct2/results? term=NCT05450822&Search=Search.

Flexible head-following motion planning for scalable and bendable continuum robots

Continuum robots, which are characterized by high length-to-diameter ratios and flexible structures, show great potential for various applications in confined and irregular environments. Due to the combination of motion modes, the existence of multiple solutions, and the presence of complex obstacle constraints, motion planning for these robots is highly challenging. To tackle the challenges of online and flexible operation for continuum robots, we propose a flexible head-following motion planning method that is suitable for scalable and bendable continuum robots. Firstly, we establish a piecewise constant curvature (PCC) kinematic model for scalable and bendable continuum robots. The article proposes an adaptive auxiliary points model and a method for updating key nodes in head-following motion to enhance the precise tracking capability for paths with different curvatures. Additionally, the article integrates the strategy for adjusting the posture of local joints of the robot into the head-following motion planning method, which is beneficial for achieving safe obstacle avoidance in local areas. The article concludes by presenting the results of multiple sets of motion simulation experiments and prototype experiments. The study demonstrates that the algorithm presented in this paper effectively navigates and adjusts posture to avoid obstacles, meeting the real-time demands of online operations. The average time for a single-step solution is 4.41×10−5 s, and the average tracking accuracy for circular paths is 7.8928 mm.

One at a Time: Progressive Multi-Step Volumetric Probability Learning for Reliable 3D Scene Perception

Numerous studies have investigated the pivotal role of reliable 3D volume representation in scene perception tasks, such as multi-view stereo (MVS) and semantic scene completion (SSC). They typically construct 3D probability volumes directly with geometric correspondence, attempting to fully address the scene perception tasks in a single forward pass. However, such a single-step solution makes it hard to learn accurate and convincing volumetric probability, especially in challenging regions like unexpected occlusions and complicated light reflections. Therefore, this paper proposes to decompose the complicated 3D volume representation learning into a sequence of generative steps to facilitate fine and reliable scene perception. Considering the recent advances achieved by strong generative diffusion models, we introduce a multi-step learning framework, dubbed as VPD, dedicated to progressively refining the Volumetric Probability in a Diffusion process. Specifically, we first build a coarse probability volume from input images with the off-the-shelf scene perception baselines, which is then conditioned as the basic geometry prior before being fed into a 3D diffusion UNet, to progressively achieve accurate probability distribution modeling. To handle the corner cases in challenging areas, a Confidence-Aware Contextual Collaboration (CACC) module is developed to correct the uncertain regions for reliable volumetric learning based on multi-scale contextual contents. Moreover, an Online Filtering (OF) strategy is designed to maintain representation consistency for stable diffusion sampling. Extensive experiments are conducted on scene perception tasks including multi-view stereo (MVS) and semantic scene completion (SSC), to validate the efficacy of our method in learning reliable volumetric representations. Notably, for the SSC task, our work stands out as the first to surpass LiDAR-based methods on the SemanticKITTI dataset.

Chemical conversion of parasitic residual lithium compounds into beneficial artificial interface for cycle life improvement of LiNi0.8Mn0.1Co0.1O2 cathodes

LiNi0.8Mn0.1Co0.1O2 (NMC811) is the suitable cathode material for 300 Wh kg−1 lithium-ion battery packs due to their high specific capacity and operating potential of ∼3.7 V. The major bottleneck in the commercialization of NMC811 arises from the formation of residual lithium compounds (RLCs) on the surface during synthesis, its accumulation during storage, and the bulk/interfacial degradation when cycled using conventional electrolytes. Removing RLCs and ceasing their reformation complicate the material production line. Herein, we propose a single-step solution of converting parasitic RLCs into beneficial artificial interfaces by reacting RLCs with LiPF6 and Lithium Bis(oxalate)borate salts in tandem. It results in a bilayer arrangement of multiple components having LiF and Li3PO4 in the inner layer and LixBOyFz in the outer layer. The interface-modified material retains 90 % of initial capacity over 200 cycles, whereas the pristine NMC811 loses ∼50% capacity. The surface modification improves coulombic efficiency, reduces voltage polarization, lowers the growth of resistances with the progression of cycling, regulates the composition of cathode-electrolyte interphase, restricts cationic disorder, and provides interfacial stability during long-term cycling. In short, the applied methodology not only mitigates the issue of detrimental RLCs but also boosts the electrochemical performances of Ni-rich cathodes significantly.

Coordination of Tetracyanoquinodimethane-Derivatives with Tris(pentafluorophenyl)borane Provides Stronger p-Dopants with Enhanced Stability.

Strong molecular dopants for organic semiconductors that are stable against diffusion are in demand, enhancing the performance of organic optoelectronic devices. The conventionally used p-dopants based on 7,7,8,8-tetracyanoquinodimethane (TCNQ) and its derivatives "FxTCN(N)Q", such as 2,3,4,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4TCNQ) and 1,3,4,5,7,8-hexafluorotetracyano-naphthoquinodimethane (F6TCNNQ), feature limited oxidation strength, especially for modern polymer semiconductors with high ionization energy (IE). These small molecular dopants also exhibit pronounced diffusion in the polymer hosts. Here, we demonstrate a facile approach to increase the oxidation strength of FxTCN(N)Q by coordination with four tris(pentafluorophenyl)borane (BCF) molecules using a single-step solution mixing process, resulting in bulky dopant complexes "FxTCN(N)Q-4(BCF)". Using a series of polymer semiconductors with IE up to 5.9 eV, we show by optical absorption spectroscopy of solutions and thin films that the efficiency of doping using FxTCN(N)Q-4(BCF) is significantly higher compared to that using FxTCN(N)Q or BCF alone. Electrical transport measurements with the prototypical poly(3-hexylthiophene-2,5-diyl) (P3HT) confirm the higher doping efficiency of F4TCNQ-4(BCF) compared to F4TCNQ. Additionally, the bulkier structure of F4TCNQ-4(BCF) is shown to result in higher stability against drift in P3HT under an applied electric field as compared to F4TCNQ. The simple approach of solution-mixing of readily accessible molecules thus offers access to enhanced molecular p-dopants for the community.

One-step synthesis of CoAl2O4 inorganic pigment by solution combustion: The impact of fuel and ammonium nitrate

Inorganic pigments are widely used in various industries, including ceramics and paints. CoAl2O4 is a highly stable pigment, but its industrial synthesis requires high temperatures, resulting in long synthesis times and high costs. Alternative synthesis routes have been proposed, but they are often expensive and require multiple thermal treatment stages. Solution combustion synthesis shows promise in reducing costs and synthesis time, but optimization is required so that synthesis is achieved in one step. In this work, we studied the problem of synthesizing the inorganic pigment CoAl2O4 using a single-step solution combustion synthesis. Therefore, the aim was to investigate the influence of different fuels: urea and citrulline, and the addition of an extra oxidizing agent, ammonium nitrate (A.N.), on the combustion temperature and the resulting structure, morphology, and colour of the pigment. The addition of A.N. resulted in a significant increase in the combustion temperature and the formation of crystalline CoAl2O4. The color coordinates for the powder following combustion, with the inclusion of 2 g of ammonium nitrate (A.N.) in the fuel mixture at an optimized O/F ratio of 0.5, were determined as follows: L* = 58.23, a* = −8.27, b* = −30.25, C*ab = −31.33, and h*ab = 263°, indicative of a blue hue. These results show that inorganic pigments could be used in ceramic decoration and acrylic paint. These findings are important for the development of new and efficient methods for synthesizing inorganic pigments with desirable properties for various applications.

Uniform flow depth in trapezoidal open channels

Uniform or normal flow depth is a key parameter for designing the open channels. The majority of irrigation channels are trapezoidal. Developing an explicit single-step solution based on Manning's formula to calculate the normal depth in trapezoidal open channels is not a simple task. This is due to special mathematical behavior of the governing uniform flow equation for some values of z < 1 (z = side slope of the channel). This work has focused on analytical-based solution. In this study, for the first time, explicit solutions for trapezoidal channels have been developed using asymptote matching technique (power mean concept). This technique enables to develop a solution for the entire flow depth range. The maximum error of proposed solution for z ≥ 1 is less than 0.7%. The efficiency of the asymptote matching technique can be improved by adding a power-law relation. According to this feature, a direct solution with a wider applicable range of z is developed. The maximum error of this solution for z ≥ 0.25 is less than 0.72%. A full range solution is also developed for rectangular channels with a maximum error less than 0.1%. The proposed explicit solutions have physical concept and high accuracy and are well-suited for practical applications.

Defect rich Ni/NiO-graphene heterostructures with oxygen bridges for enhanced electrocatalytic glucose oxidation towards selective sensing

Defect rich Ni/NiO-graphene heterostructures were developed by combining electrocatalytically active Ni/NiO nanocomposite with graphene sheets using a facile single step solution combustion method. The synthesised electrocatalyst was characterized using XRD, Raman, FTIR, XPS, FESEM, TEM and HRTEM techniques. Ni–O–C linkage was evidenced from XPS spectrum in concurrent with G-band shift in Raman spectrum showed the effective integration of active nanocomposite with graphene sheets. Moreover, the wide distribution of active nanocomposite material on graphene sheets with a greater number of defect sites within NiO lattices would expose catalytically active sites for electrochemical redox reaction and synergistic effects of these heterostructures on the electrochemical behaviour of Ni/NiO-GS hybrid nanocomposite employing EIS, CV and CA techniques were discussed. Excellent improvement in the Ni2+/Ni3+ redox activity and enhancement in the glucose oxidative property of Ni/NiO-GS/GCE with respect to Ni/NiO/GCE was contributed to the availability of more electrochemical active surface area and the combined effect of increased mass transport and charge transfer kinetics. The amperometry response of Ni/NiO-GS/GCE towards glucose over a wide linear range (0.5 mM–7.5 mM) with good sensitivity (696 μA mM−1 cm−2) and high correlation coefficient (0.9959) at an applied potential of about 0.495 V vs Ag/AgCl with anti-interference ability, repeatable and reproducible glucose oxidative current responds with an estimated relative standard deviation of 0.018 and 0.014 respectively makes it as a prospective electrode material for cost-effective glucose selective sensor.

Single-step solution combustion synthesis of porous 1393-B3 glass powders and structural characterization via solid-state NMR spectroscopy

Single-step solution combustion synthesis of porous 1393-B3 glass powders and structural characterization via solid-state NMR spectroscopy

Catalyst-Free Single-Step Solution Polycondensation of Polyesters: Toward High Molar Masses and Control over the Molar Mass Range

Catalyst-Free Single-Step Solution Polycondensation of Polyesters: Toward High Molar Masses and Control over the Molar Mass Range

Synergistic modulation of active site of NiO via cobalt doping by solution combustion for improving oxygen evolution reaction

The development of robust, highly efficient, inexpensive electrocatalyst for the oxygen evolution reaction (OER) is very necessary to minimize the overpotential of water splitting and boosts up the practicality of related energy systems. Here in nanoparticles of cobalt doped NiO of the composition Ni1-xCoxO (X = 0, 0.1, 0.2, 0.3, 0.4, 0.5) have been successively synthesized via single step solution combustion method (SCM). The time and energy saving SCM is a self-sustained combustion reaction which helps to control the morphology and size of the nanomaterials. Doping of oxides and construction of hetero junctions are some of the distinctive advantages of SCM. During the combustion process large amount of gas evolution will take place and produce nanomaterial with large specific surface area and porosity, which provide some exceptional behavior to the resulting nanomaterials. The results of structural characterization show that SCM is a functional strategy for the synthesis of pure single-phase Co doped NiO nanoparticles. Among the series of Co doped NiO, Ni0.6Co0.4O showed drastically enhanced OER activity with much lower overpotential of 370 mV and a lower Tafel slope of 69 mV/dec and display good stability in alkaline media. The OER performance of Co doped NiO is higher because of the improved electronic conductivity caused by the partial substitution of Ni2+ by Co2+ in the NiO matrix. In addition, as the Co concentration increases the porous nature of NiO also increases up to x = 0.4 after that aggregation of nanoparticles takes place.The porous nature of material helps to expand the contact area of electrode and electrolyte and favors more active sites for OER. The strategy used for doping Co into NiO proposes a new way to develop electrochemically active material for OER.

Development of highly active and coke-resilient Ni-based catalysts for low-temperature steam reformation of methane

In this work, we report on the development of highly active and stable catalysts for low temperature steam reformation of methane. The Ni-based catalysts supported on alumina were synthesized by the single step solution combustion synthesis (SCS) method. A combination of various surface and bulk sensitive analytical techniques such as XRD, cyclic TPDRO, XPS and HRTEM-SAED was utilized for detailed characterization of the catalysts. The catalyst 5NC synthesized by the SCS method exhibited superior activity and excellent stability for steam reformation of methane during the investigated period on stream for around 200 h. The light-off for methane conversion over the 5NC catalyst started at a reaction temperature of 350 °C whereas for the 5NP catalyst no activity below 600 °C was observed. Moreover, full methane conversion over the 5NC catalyst was achieved at 700 °C. Under similar conditions at reaction temperature of 700 °C, the methane decomposition rates over the 5NC catalyst was around 20 times higher than that of the 5NP catalyst. The exceptional high performance of the 5NC catalyst was attributed to the presence of surface defects, generation of nickel aluminates (NiAl2O4) nano-crystallites, uniform distribution and smaller metal oxide particle size.

Protease Immobilization in Solution-Blown Poly(ethylene oxide) Nanofibrous Nonwoven Webs

Enzyme-functionalized solution-blown nonwoven (EFSBN) fibers were produced by a single-step solution blow spinning method that utilizes high-velocity gas to simultaneously extrude the codissolved polymer–solvent–enzyme spinning solution and evaporate solvent at mild conditions to form a nanofibrous web with preserved enzyme activity. A broad concentration range of 0.6–7.4 wt % protein of subtilisin A protease from Bacillus licheniformis was successfully entrapped by poly(ethylene oxide) (PEO) during solution blow spinning nonwoven web production. The presence of enzyme protein in the solid nanofibers was detected by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. Time of flight-secondary ion mass spectroscopy and laser confocal microscopy revealed the immobilized enzymes were mainly positioned inside the fibers and homogeneously distributed throughout the webs. Scanning electron microscopy showed that the fiber shape and diameter of PEO nanofibers containing enzymes were irregular compared to PEO-only nanofibers. Residual enzyme activity in the webs was measured by redissolving fibers in buffer and comparing the released enzyme activity to nonimmobilized free enzyme using a casein substrate-based assay. Immobilized protease (1.3% (w/w) protein in solid dry nanofiber webs) retained more than 90% of the free enzyme activity. Protease immobilized in solid nanofiber webs exhibited long storage stability at ambient (∼22 °C) and 4 °C temperature storage conditions, with more than 60% remaining catalytic activity after 300 days compared to the initial activity. Immobilized protease had equally good thermal stability as a stabilized liquid commercial protease, both retaining above 95% of their initial activity after treatment for 12 h at 65 °C. In contrast, the same liquid protease diluted in buffer lost activity within 2 h at that temperature. The nondusting, readily aqueous-soluble EFSBN solid materials are easy to handle and have good storage stability compared to liquid products.

A cohesive effort to assess the suitability and disparity of carbon nanotubes for water treatment.

Population growth, industrialization, and the extensive use of chemicals in daily life have all contributed to an increase in waste generation and an intensified release of organic pollutants into the aquatic environment. To ensure the quality of water (including natural resources), the removal of these pollutants from wastewater has become a challenging task for scientific community. Conventional physical, chemical, and biological treatment methods are commonly used in combinations and are not very effective. Recently, carbon nanotubes (CNTs) emerged as the most reliable and adaptable choice for efficient water treatment due to their extraordinary material properties appearing as a single-step solution for water treatment. High surface area, exceptional porosities, hollow and layered structures, and ease of chemical activation and functionalization are some properties which makes it excellent adsorption material. Hence, this review paper discusses the recent advances in the synthesis, purification, and functionalization of CNTs for water and wastewater treatment. In addition, this study also also provides a quick overview of CNTs-based advance technologies employed in water treatment and carefully assesses the benefits versus risks during large-scale water treatment. Furthermore, it concludes that identified risks to the environment and human health cannot be easily ignored and strict regulatory requirements are a must for producing low-cost innoxious CNTs.

Self-Assembled Conjugated Small Molecular Electrolytes for the Formation of an Electron Transporting Layer via Single-Step Solution Processing for BHJ Solar Cells

Indolocarbazole (Ic) conjugated small molecular electrolytes (CSMEs) with different amine side chains are synthesized and applied to the formation of an electron transporting layer (ETL), via spontaneous phase separation, in bulk heterojunction (BHJ) polymer solar cells (PSCs). The self-assembled bilayer with a BHJ-active layer on top and a CSME layer at the bottom is generated by a single coating step of one solution of CSME and BHJ-active layer materials, CSME:PTB7-Th:PC71BM. The location of the CSME layer is confirmed by time-of-flight secondary ion mass spectroscopy. The CSME layer plays the role of an ETL, which reduces the work function of indium tin oxide (ITO) effectively and leads to high power conversion efficiency (PCE) of the CSME-modified PSC. We also use X-ray photoelectron spectroscopy to test the relative intensity of hydrogen bonds between the CSME and ITO. With the increased relative intensity of hydrogen bonds between the CSME and ITO, more effective spontaneous phase separation of the CSME/BHJ bilayer can be formed to generate the CSME layer on top of ITO, and the photovoltaic performance of the PSC enhanced. Out of the synthesized series of CSMEs (IcL4N, IcL6N, IcL8N, IcL10N, and IcB8N), the IcB8N-based device shows the highest relative intensity of hydrogen bonding and the highest PCE with a value of 7.09% without using any other ETL materials, which is the highest PCE value without using any other ETL in a separate processing step, in I-PSCs utilizing PTB7-Th:PC71BM.

Selective Reduction of CO2 on Ti2C(OH)2 MXene through Spontaneous Crossing of Transition States.

Direct reduction of gas-phase CO2 to renewable fuels and chemical feedstock without any external energy source or rare-metal catalyst is one of the foremost challenges. Here, using density functional theory and ab initio molecular dynamics (AIMD) simulations, we predict Ti2C(OH)2 MXene as an efficient electron-coupled proton donor exhibiting simultaneously high reactivity and selectivity for CO2 reduction reaction (CRR) by yielding valuable chemicals, formate, and formic acid. This is caused by CO2 spontaneously crossing the activation barrier involved in the formation of multiple intermediates. Metallic Ti2C(OH)2 contains easily donatable protons on the surface and high-energy electrons near the Fermi level that leads to its high reactivity. High selectivity arises from low activation barrier for CRR as predicted by proposed mechanistic interpretations. Furthermore, H vacancies generated during the product formation can be replenished by exposure to moisture, ensuring the uninterrupted formation of the products. Our study provides a single-step solution for CRR to valuable chemicals without necessitating the expensive electrochemical or low-efficiency photochemical cells and hence is of immense interest for recycling the carbon.