Direct Conversion Research Articles

Coke Formation and Regeneration during Fe-ZSM-5-Catalyzed Methane Dehydro-Aromatization

Coke formation poses a significant obstacle in the direct conversion of methane into valuable chemicals such as ethylene, benzene, and hydrogen via methane dehydro-aromatization (MDA). At the elevated temperatures necessary for this reaction, coke is the thermodynamically favored product, causing rapid catalyst deactivation and hence necessitating frequent catalyst regeneration. Successful industrial implementation of MDA requires the advancement of catalyst regeneration processes and a comprehensive understanding of coke formation to enhance catalyst performance. Here, we examined the types of coke generated during MDA over a Fe-ZSM-5 catalyst and their impact on deactivation. By combining reactivity studies using catalysts with carefully controlled coke populations with the characterization of the catalyst via XRD, H2-TPR, and pyridine FTIR, we find that soft coke is formed at the Brønsted acid sites, resulting in loss of selectivity, while hard coke is formed at the metal sites causing a loss of activity. While soft coke can be removed at low regeneration temperatures, the removal of hard coke requires harsh conditions which compromise catalyst stability. An investigation into the use of CO2 as an alternative, mild oxidant for catalyst regeneration, however, shows that the mild oxidation strength of CO2 requires even higher regeneration temperatures and hence irreversible loss of Brønsted acid sites.

To the question of construction of welding inverter sources with a high power factor

Purpose. Design a power-factor-corrected, energy- and cost-efficient switchmode power supply for welding. Methodology. It is proposed to use the principle of direct conversion and to develop the "hybrid" power circuit consisting of a main power path using direct conversion and an auxiliary power path having a converter with an intermediate DC link with relatively low stored energy. Since a load to the welding power supply is the welding arc, its instantaneous power fluctuations during the mains voltage period essentially do not influence the welding process due to the thermal constant of the weld pool molten metal. Effective use of this features of the welding arc allows to optimize the power processing, reduce the amount of energy stored in the reactive elements of the circuit and improve the economical, mass and dimensional parameters of the supplies. Findings. A new power factor corrected switchmode power supply topology is proposed utilizing beforementioned principles of power processing. The algorithm for calculating the switching frequency of supply power switches is given. To confirm the adequacy of the developed provisions, an experimental sample of the power supply was created. Oscillograms of mains voltage and source current consumption and oscillograms in output current limitation mode are obtained. The results of experiments showed that the supply has a power factor > 0.94 in a wide range of powers. Originality. A distinctive feature of the supply is the absence of additional inductive components in the power path, a lower capacitance of the DC-link bulk capacitor and a simplified scheme for limiting its inrush current during initial charging. The supply has an increased open circuit voltage, independent of the mains voltage, which allows for easy arc ignition during manual arc welding. Practical value. Due to the increased power factor, the current drawn from the mains is 30 % to 45 % lower than that of widespread inverter supplies without a power factor corrector. These features allow to simultaneously use more power supply units with the same mains current load, and/or to provide stable welding in conditions of a "weak" mains.

One-pot direct conversion of raw straw to furan chemicals simultaneously in a choline chloride-lactic acid/methyl isobutyl ketone biphasic system

One-pot direct conversion of raw straw to furan chemicals simultaneously in a choline chloride-lactic acid/methyl isobutyl ketone biphasic system

Realizing BiCuSeO-based thermoelectric device for ultrahigh carrier mobility through texturation

The thermoelectric conversion technology, as a promising renewable energy technology, enables direct and efficient conversion between electricity and heat. In the past ten years, there has been an increasing curiosity towards oxide thermoelectric materials due to their environmentally friendly nature, low cost, and excellent thermal and chemical stability. However, the intrinsic low carrier mobility of BiCuSeO limits its potential to be a high-performance thermoelectric material. Herein, we propose a dynamic sintering approach to enhance carrier mobility of BiCuSeO. As a result, carrier mobility at room temperature of three-step textured Bi0.94Pb0.06Cu0.97Se1.05O0.95 reaches an ultrahigh value of 13.1 cm2 V−1 s−1, which is the highest reported in the conventional doping of BiCuSeO system. Based on the ultrahigh carrier mobility, the power factor of three-step textured Bi0.94Pb0.06Cu0.97Se1.05O0.95 sample could reached 20 μV cm−1 K−2 near room temperature, and the average power factor of 300–923 K could reach 18.0 μV cm−1 K−2, effectively optimizing the electrical performance throughout the entire test temperature span. As a result, we successfully attain a ZT of ∼ 1.5 at 923 K and a ZTave of 0.89 within the temperature span of 300–923 K for three-step textured Bi0.94Pb0.06Cu0.97Se1.05O0.95 sample. Based on the outstanding performance, we have successfully built a 7-pair thermoelectric device based on three-step textured Bi0.94Pb0.06Cu0.97Se1.05O0.95 paired with the N-type two-step textured Bi2Te2.7Se0.3Cu0.01, which is the first BiCuSeO-based thermoelectric device. The thermoelectric device, exhibits a maximum conversion efficiency of 2.8 % at the temperature difference 215 K and simultaneously achieves a cooling temperature difference of 23.5 K with the hot end at 286 K. This work indicates that texturation is an effective approach for enhancing the carrier mobility of oxide TE materials. Besides, BiCuSeO oxyselenide is promising for pollution-free and cost-effective thermoelectric devices of power generation and cooling, thereby offering potential implications for sustainable energy solutions.

Carbon dioxide capture by direct methanation in co-electrolysis using solid oxide cell

Reducing carbon emissions in the global economy's energy and industry sectors necessitates not just the implementation of innovative low-emission technologies but also the adoption of techniques for capturing and recycling CO2. The Power-to-X conversion allows the path to the reuse of CO2 originating from fossil fuels burning and other industrial processes, hence reducing the emission of the key greenhouse gas. The use of high-temperature electrochemical devices for such purposes is a promising solution, which has been already deployed as subsidized demo projects. In the present work, the direct electrolysis of the H2O-CO2-H2 mixtures with in situ conversion of CO2 and CO to CH4 was effectively conducted in the temperature range of 575–650 °C using commercial solid oxide half-cell with YSZ-type electrolyte on Ni-YSZ support with a custom lanthanum‑strontium cobaltite anode. The degree of carbon conversion in the atmosphere enriched with hydrogen was close to 90%, but under such conditions, the products are diluted to 5–6 vol% in H2. Reducing the temperature leads to a sufficient increase in the CH4 outcome, but it is constrained by the decline of the cell performance. Electrochemical processes were monitored by impedance spectroscopy and analyzed using the distribution of the relaxation times technique. Analysis of the distribution of relaxation times of impedance spectra showed that two parallel competitive processes can be attributed to CO2 conversion. Peak with characteristic time c.a. 0.1 s might be associated with diffusion-like mass transfer through cermet support, and it plays an important role in the electrochemical conversion at elevated temperature and high current density. Conversely, the peak observed in the vicinity of 5 ms becomes the limiting stage at lower temperature and probably is related to charge transfer or absorption and surface diffusion of carbon-containing species. Electrolysis current density might reach 0.4 A cm−2 even at 600 °C without explicit damage to the electrolyte or electrodes. A brief degradation test demonstrated a minor loss in the electrochemical performance of the cell. Thus, it was demonstrated that direct electrochemical conversion of CO2 to CH4 can be achieved with sufficient productivity using a semi-commercial cell with an active surface of 16 cm2 under conditions compatible with those existing in the state-of-the-art stacks of solid oxide cells.

A straightforward chemobiocatalytic route for one-pot valorization of glucose into 2,5-bis(hydroxymethyl)furan

Direct conversion of inexpensive biomass into value-added chemicals via furanic platform molecules is highly attractive. In this work, we present a straightforward chemobiocatalytic route for glucose valorization into 2,5-bis(hydroxymethyl)furan (BHMF) in one pot, with no purification of the intermediate 5-hydroxymethylfurfural (HMF). Six candidate alcohol dehydrogenase (ADH) genes were located from Meyerozyma guilliermondii SC1103, based on comparative transcriptome analysis and real-time quantitative polymerase chain reaction. An ADH (MgADH1) was identified upon evaluation of catalytic performances of recombinant Saccharomyces cerevisiae harboring candidate ADHs in HMF reduction. Soluble expression of the enzyme in S. cerevisiae was greatly enhanced by its codon optimization, leading to improved HMF tolerance (up to 400 mM). In a fed-batch process, the desired product of approximately 473 mM (60.5 g/L) was produced within 30 h by recombinant S. cerevisiae_MgADH1. A chemobiocatalytic route toward BHMF was constructed by merging CaCl2-mediated isomerization and dehydration with biocatalytic reduction with an overall yield of approximately 42%, starting from glucose. This work may pave the way for green manufacture of valuable biobased chemicals.

Wet torrefaction of biomass waste into high quality hydrochar and value-added liquid products using different zeolite catalysts

Wet torrefaction (WT) proves to be a highly efficient pretreatment method for biomass waste, resulting in the production of hydrochar and valuable liquid products. In this study, a groundbreaking chemocatalytic approach is introduced, employing various zeolite catalysts (H-ZSM-5, H-Beta, H–Y, H-USY, and H-Mordenite) in a batch reactor under a nitrogen atmosphere. This method enables the simultaneous one-pot production of levulinic acid (LA) and/or bio-ethanol during the WT process of wood cellulose pulp residue (WCPR), ultimately yielding high-quality solid fuel. The WT process involves at 220 and 260 °C, H2O/WCPR = 10, and torrefaction time at 15, 30 and 60 min. The study identifies that at 220 °C and 15 min, as the optimal temperature and time, for bio-ethanol production, achieving a selectivity of 59.0 % with the H–Y catalyst, while the highest amount of bio-ethanol (75.6 %) was detected in presence of H-USY zeolite at 260 °C after 60 min. In addition, it was found the formation of relatively high amount of LA (62.0 %) at 220 °C after 60 min but using the H-ZSM-5 catalyst. For the WT + Mordenite sample (220 °C, 60 min), the highest carbon content of 71.5 % is achieved, resulting in the higher heating value (HHV) of 27.3 MJ/kg, an enhancement factor of 1.36, and carbon enrichment of 1.48, with the sequence of element removal during WT prioritized as DO > DH > DC and the weight loss of 68 %. Finally, the reaction mechanism was proposed to elucidate the formation of liquid products after WT of WCPR with participation of zeolite catalysts. The main pathway involving the direct conversion of cellulose into hydroxyacetone, followed by the subsequent generation of ethanol through the C–C cleavage of hydroxyacetone while LA formed via well-known route which includes cellulose hydrolysis to form glucose, conversion to 5-HMF and the subsequent transformation of 5-HMF into LA.

The fabrication and characterization of direct conversion flat panel X-ray imager with TlBr film

The novel direct conversion flat panel detectors (FPDs) utilizing thallium bromide (TlBr) films are developed and characterized in this study. Thin TlBr films, deposited using an evaporation technique, achieved thicknesses of 10 μm and 50 μm. A pixel sensor array, with a pixel size of 235 × 235 μm2 and a sensitive area of 29.61 × 39.48 mm2, was developed using low-temperature polysilicon thin-film transistor (LTPS TFT) technology as the initial study to explore performance characteristics of developed imaging system. The TlBr film was characterized based on the current-voltage (I–V) profile, showing a resistivity of 2.78 × 1010 Ω·cm. The LTPS TFT showed a leakage current of about 10−13 A, while the noise of TlBr FPD system was around 104 e− rms, primarily limited by the readout system. The detector system was characterized using radiation from an X-ray tube with a voltage in the range of 30 kV–100 kV and a current of 2 mA, involving an X-ray test chart as the object with the processing time of 18.15–18.30 ms per frame. Based on the contrast and contrast-to-noise ratio (CNR) values, the 10 μm and 50 μm TlBr FPD clearly captured the image in operation between 30 kV and 100 kV. The 50 μm TlBr FPD demonstrated improved sensitivity, showing pixel values with 10 times higher intensity and enhanced line pair detail at 30 kV X-ray operation. The 10 μm TlBr achieved spatial resolution of 267 μm full width at half maximum (FWHM), while the 50 μm TlBr achieved 250 μm FWHM. In the X-ray imaging demonstration, the shape and structure of anchovy was clearly distinguished. The TlBr film FPD presents promising potential for a room temperature X-ray imager.

Green Catalytic Synthesis of Ethylenediamine from Ethylene Glycol and Monoethanolamine: A Review.

Ethylenediamine (EDA) is a crucial chemical raw material and fine chemical intermediate. Compared with the industrial approach of ammonolysis of 1,2-dichloroethane, the catalytic amination of ethylene glycol (EG) is an economical and environmentally benign route that will be the future trend for EDA synthesis. Herein, we systemically review the recent progress in direct and indirect catalytic conversion of EG to EDA. Furthermore, different types of catalysts are discussed: (i) supported metal and multimetallic catalysts, (ii) solid acid catalysts, and (iii) other active catalysts (e.g., ionic liquids and metal complexes). Finally, we conclude with the frontiers and future prospects of the catalytic synthesis of EDA from EG and monoethanolamine, providing readers a snapshot of this field.

Direct conversion of methane to aromatics and hydrogen via a heterogeneous trimetallic synergistic catalyst

Non-oxidative methane dehydro-aromatization reaction can co-produce hydrogen and benzene effectively on a molybdenum-zeolite based thermochemical catalyst, which is a very promising approach for natural-gas upgrading. However, the low methane conversion and aromatics selectivity and weak durability restrain the realistic application for industry. Here, a mechanism for enhancing catalysis activity on methane activation and carbon-carbon bond coupling has been found to promote conversion and selectivity simultaneously by adding platinum–bismuth alloy cluster to form a trimetallic catalyst on zeolite (Pt-Bi/Mo/ZSM-5). This bimetallic alloy cluster has synergistic interaction with molybdenum: the formed CH3* from Mo2C on the external surface of zeolite can efficiently move on for C-C coupling on the surface of Pt-Bi particle to produce C2 compounds, which are the key intermediates of oligomerization. This pathway is parallel with the catalysis on Mo inside the cage. This catalyst demonstrated 18.7% methane conversion and 69.4% benzene selectivity at 710 °C. With 95% methane/5% nitrogen feedstock, it exhibited robust stability with slow deactivation rate of 9.3% after 2 h and instant recovery of 98.6% activity after regeneration in hydrogen. The enhanced catalytic activity is strongly associated with synergistic interaction with Mo and ligand effects of alloys by extensive mechanism studies and DFT calculation.

Aluminum-catalyzed direct conversion of lactones to selenolactones in the presence of elemental selenium and its application in the indium-catalyzed syntheses of dibenzyl selenides from benzyl acetates

Se-containing compounds exhibit novel chemical properties and unique pharmacological effects. Although various methods of preparing selenoesters have been reported, the synthetic focus on the related cyclic selenoesters remains insufficient. The conventional methods of synthesizing selenolactones generally involve multistep processes. In this study, an AlBr3/PhSiH3 (Ph = Phenyl) reducing system selectively catalyzed the one-pot conversion of γ-aryl-γ-lactones and elemental Se to γ-aryl-γ-selenolactones in good yields. This reducing system strongly activates elemental Se rather than elemental S. Additionally, an In(OAc)3/PhSiH3 (OAc = acetate) reducing system effectively catalyzed the direct conversion of linear benzyl acetates, which constitute substructures of lactones, and elemental Se to dibenzyl selenide derivatives.

Testing of an organic metal halide perovskite for fast neutron detection

In this work, we synthesized and characterized the Methylhydrazinium Lead Trichloride MHyPbCl3(CH3NH2NH2PbCl3) perovskite as a fast neutron detector. The high hydrogen density of MHyPbCl3 enables efficient energy conversion from a fast neutron into a recoiled proton through the 1H(n,n)1H elastic scattering interaction, thereby, allowing for direct charge detection. Through IV characterization and X-Ray excitation, the crystal demonstrated a high resistivity at 4.43E11Ωcm and a good mobility-lifetime product (μτ) of 9.1E-3 cm2V, respectively, under C60/BCP/Cu and Au contact configuration to form an ohmic-ohmic detector. The crystal showed a good sensitivity to X-rays using an x-ray tube. The feasibility of the direct neutron conversion detector is demonstrated using the fast neutron beam at a Research Reactor. Waveforms from a charge-sensitive pre-amplifier showed distinct radiation-induced pulses from the MHyPbCl3 detector in response to the reactor neutron beam. Using a thermal neutron filter and gamma shielding in the beam, we showed that the pulses produced were more likely from neutron interactions, despite the Pb containing MHyPbCl3 is also sensitive to gamma-rays. With those fast neutron pulses, a post-pulse processing code was used to conduct pulse height analysis (PHA) and reconstruct an energy spectrum.

A covalent organic framework integrating photocatalytic center and electron reservoir for photocatalytic CO2 reduction to HCOOH

Direct and efficient photocatalytic conversion of CO2 into fuels and high value-added chemicals under sunlight is of great significance in alleviating the energy crisis and environmental issues. Covalent organic frameworks (COFs) have attracted much attention in the photocatalytic field as materials that can be pre-designed on demand. Taking advantage of the pre-designable properties of COFs materials, the integration of organic building blocks with photocatalytic activity and photoelectron-resident properties into frameworks can improve the electron-hole separation efficiency and photocatalytic performance. Here, we report a newly designed COF (COF-TVBT-N) with triazine and alkenyl groups that can be used as a photocatalyst to accomplish the photoreduction of CO2 to HCOOH under simulated sunlight without the assistance of metal sites and photosensitizers. Furthermore, we unambiguously reveal that the photocatalytic active center in COF-TVBT-N is TVBT through the combination of experiments and theoretical calculations. DFT calculations suggest that the adsorption of H near the active center is beneficial for the adsorption and photoreduction of CO2 in this photocatalytic system. The photoexcitation process and photocatalytic CO2 reduction mechanism of COF-TVBT-N are also reasonably deduced based on DFT calculations. This work provides ideas for the design of COFs as photocatalysts for CO2 reduction and gives insights into the mechanism of CO2 conversion to HCOOH.

Uranyl‐Organic Framework as Hydrogen Atom Transfer Catalyst for Visible‐Light‐Driven Heterogeneous Hydroacylation of Azodicarboxylates

AbstractThe direct C−H to C−N bond conversion at room temperature using heterogeneous visible‐light catalysts is both interesting and challenging. Herein, we disclosed visible‐light‐promoted hydroacylation of azodicarboxylates using uranyl‐organic framework [UO2(OH)(cpt)]n (Ucpt, Hcpt=4‐(4′‐carboxyphenyl)‐1,2,4‐triazole) as an efficient heterogeneous hydrogen atom transfer photocatalyst. In this procedure, diverse benzaldehydes are compatible using dimethyl carbonate (DMC) as a green solvent at room temperature, achieving direct conversion of C−H to C−N bond with excellent yields (up to 99%). The key to excellent catalytic activity lies in the fact that the coordination of the conjugated ligand changes the HOMO energy level of Ucpt, resulting in more active sites and longer‐lived photo excitons. Simultaneously, this heterogeneous photocatalyst can be easily separated and reused for seven successive cycles and maintain high catalytic activity, showing outstanding sustainability and recyclability.

Conversion of single-energy CT to parametric maps of dual-energy CT using convolutional neural network.

We propose a deep learning (DL) multitask learning framework using convolutional neural network for a direct conversion of single-energy CT (SECT) to 3 different parametric maps of dual-energy CT (DECT): virtual-monochromatic image (VMI), effective atomic number (EAN), and relative electron density (RED). We propose VMI-Net for conversion of SECT to 70, 120, and 200 keV VMIs. In addition, EAN-Net and RED-Net were also developed to convert SECT to EAN and RED. We trained and validated our model using 67 patients collected between 2019 and 2020. Single-layer CT images with 120 kVp acquired by the DECT (IQon spectral CT; Philips Healthcare, Amsterdam, Netherlands) were used as input, while the VMIs, EAN, and RED acquired by the same device were used as target. The performance of the DL framework was evaluated by absolute difference (AD) and relative difference (RD). The VMI-Net converted 120 kVp SECT to the VMIs with AD of 9.02 Hounsfield Unit, and RD of 0.41% compared to the ground truth VMIs. The ADs of the converted EAN and RED were 0.29 and 0.96, respectively, while the RDs were 1.99% and 0.50% for the converted EAN and RED, respectively. SECT images were directly converted to the 3 parametric maps of DECT (ie, VMIs, EAN, and RED). By using this model, one can generate the parametric information from SECT images without DECT device. Our model can help investigate the parametric information from SECT retrospectively. DL framework enables converting SECT to various high-quality parametric maps of DECT.

Direct conversion of monopotassium L-aspartate by electrodialysis metathesis: Stack resistance, co-ion transport, and concentration polarization

The conventional method of synthesizing high-value amino salt from amino acid ammonium involves several steps including acidification, precipitation, and separation. This process not only consumes acids and bases but also generates a substantial amount of wastewater. In this study, monoammonium L-aspartate was directly converted to monopotassium L-aspartate (Asp-K) using electrodialysis metathesis (EDM). To achieve this, K2SO4 was chosen as the optimum potassium salt to supply K+ due to its relatively lower co-transport rate with SO42− ions and lower stack resistance. Additionally, the membrane type was optimized as CIS/AIS membranes due to their low stack resistance, high ion permeability for the transport of Asp− ions, and low concentration polarization. The process resulted in high-purity Asp-K (99.8 %) and low energy consumption (0.14 kWh/kg Asp-K). These results indicate that the EDM process is a promising method for converting amino salts with high purity.

Rocking-Chair Aqueous Fluoride-Ion Batteries Enabled by Hydrogen Bonding Competition.

Aqueous fluoride ion batteries (FIBs) have garnered attention for their high theoretical energy density, yet they are challenged by sluggish fluorination kinetics, active material dissolution, and electrolyte instability. Here, we present a room temperature rocking-chair aqueous FIBs featuring KOAc-KF binary salt electrolytes, enabling concurrent fluorination and defluorination reactions at both cathode and anode electrodes. Experimental and theoretical results reveal that acetate ions in the electrolyte compete with fluoride ions in hydrogen bonding formation, weakening the excessively strong solvation between H2O and F- ions. This results in the suppression of detrimental HF formation and a reduced desolvation energy of F- ions, enhancing the electrochemical reaction kinetics. The bismuth-based cathode exhibits direct conversion in the optimized electrolyte, effectively suppressing the detrimental disproportionation reactions from Bi2+ intermediates. Additionally, zinc anode undergoes a typical fluorination process, forming solid KZnF3 as the electrode product, minimizing the risks of hydrogen evolution. The proposed aqueous FIBs with the optimized electrolyte demonstrate high discharge capacity, long-term cycling stability and excellent rate capabilities.

Rocking‐Chair Aqueous Fluoride‐Ion Batteries Enabled by Hydrogen Bonding Competition

AbstractAqueous fluoride ion batteries (FIBs) have garnered attention for their high theoretical energy density, yet they are challenged by sluggish fluorination kinetics, active material dissolution, and electrolyte instability. Here, we present a room temperature rocking‐chair aqueous FIBs featuring KOAc‐KF binary salt electrolytes, enabling concurrent fluorination and defluorination reactions at both cathode and anode electrodes. Experimental and theoretical results reveal that acetate ions in the electrolyte compete with fluoride ions in hydrogen bonding formation, weakening the excessively strong solvation between H2O and F− ions. This results in the suppression of detrimental HF formation and a reduced desolvation energy of F− ions, enhancing the electrochemical reaction kinetics. The bismuth‐based cathode exhibits direct conversion in the optimized electrolyte, effectively suppressing the detrimental disproportionation reactions from Bi2+ intermediates. Additionally, zinc anode undergoes a typical fluorination process, forming solid KZnF3 as the electrode product, minimizing the risks of hydrogen evolution. The proposed aqueous FIBs with the optimized electrolyte demonstrate high discharge capacity, long‐term cycling stability and excellent rate capabilities.

Conversion of Lithium Chloride into Lithium Hydroxide Using a Two-Step Solvent Extraction Process in an Agitated Kühni Column

A significant consequence of the green transition is the growing demand of lithium-ion batteries (LIBs), as they are essential for electrical vehicles. In turn, the demand for the raw materials that are needed to produce LIBs is increasing. A common LIB cathode type for electrical cars is lithium nickel manganese cobalt oxide (NMC). Since cobalt is currently considered as a critical raw material, nickel-rich NMC cathodes are now designed with lower cobalt contents. The synthesis of these new NMC types requires LiOH instead of Li2CO3, which was used for Co-richer NMC materials in the past. Most production routes of LiOH start from Li2CO3 or Li2SO4. However, LiCl could also be a potential precursor for LiOH, as it could be obtained from various lithium sources. A two-step solvent extraction process (SX) was developed for direct conversion of LiCl into LiOH, using a phenol (butylhydroxytoluene or BHT) and a mixture of quaternary ammonium chlorides (Aliquat 336) in an aliphatic diluent (Shellsol D70) as the solvent. The SX process was validated in counter-current mode using a rotary agitated Kühni extraction column. The use of a column instead of mixer-settlers reduced the CO2 uptake by the final product (LiOH), which prevented the partial conversion of LiOH to Li2CO3. A total of 75 L of LiCl feed solution was processed in the Kühni column to obtain a solution of LiOH with a final purity of more than 99.95%, at a yield of 96%.Graphical

A photoelectrochemical biosensor based on self-calibration platform of carbon-rich plasmonic probe with near-infrared driving signal amplification

Exploring the photochemical (PEC) method induced by low-energy light source makes great significance to achieve high stability and accurate analysis. A sensing platform driven by near-infrared (NIR) light was designed by making the biochemically encoded carbon rich plasmonic hybrid (CPH) probe, the peptide@C–Mo2C. The inherent plasmonic effect of C–Mo2C CPH can directly absorb NIR light, thus starting effective electronic-hole pairs separation. Moreover, the photothermal effect of C–Mo2C CPH also promoted the reaction yield of photothermal catalyst reaction on sensing interface to assist the PEC signal amplification. In the presence of target trypsin, it cleaves the peptides, resulting in the release of peptide@C–Mo2C probe from interface, which leads to a relative decrease in PEC signal. More importantly, a self-calibration system consisting of two independent PEC test channels attempted to eliminate the influence of background signal and baseline drift. The test channel was used to specify the recognition target, while the blank channel was used as a reference. Therefore, the signal difference between two channels was recorded, so as to obtain results with less error and higher stability. In this NIR driven PEC sensor, the carbon rich probe with direct and efficient NIR light conversion promoted the sensitivity and a self-calibration system guaranteed the stability which provided innovative thoughts for developing ingenious PEC sensor.