COOH Bonds Research Articles

Spin-dependent activity of cobalt contained hydroxy double perovskite for efficient antibiotic removal via peroxymonosulfate activation

Cobalt-containing catalysts exhibit good performance in the advancement of efficient catalytic oxidation reactions. However, achieving an optimal balance between reaction kinetics and adsorption, usually governed by variable spin states of Co ions, to enhance the performance remains a significant challenge. This study aims to develop a convenient compositional tuning strategy to achieve such balance in stable CoxZn1-xSn(OH)6 perovskite hydroxides. We systematically investigate the effect of varying spin state on a chosen representative catalytic oxidation reaction, namely peroxymonosulfate activation and tetracycline hydrochloride removal. The magnetic properties analysis reveal that the content of octahedral Co2+ ions with high-spin state increases with Co content (x) and reaches 59.5 % in Co0.5Zn0.5Sn(OH)6. Experimental results and DFT calculations reveal that the spin states transition of Co2+ ions enhance the interaction between Co and O atoms. This enhanced interaction not only improves the reactivity due to the formation of highly covalent Co-OH bonds that serve as catalytically activated charge transfer channels, but also optimizes the suitable adsorption energy of PMS molecules at −3.52 eV for Co0.5Zn0.5Sn(OH)6. Consequently, Co0.5Zn0.5Sn(OH)6 shows superior catalytic activity, achieving nearly 100 % antibiotic removal efficiency within just 10 min, surpassing previously reported catalysts. These findings underscore the potential of compositional tuning spin states of transition metal ions in advancing oxidation processes and designing innovative catalysts.

One-Step Organic Synthesis of 18β-Glycyrrhetinic Acid-Anthraquinone Ester Products: Exploration of Antibacterial Activity and Structure-Activity Relationship, Toxicity Evaluation in Zebrafish.

To combine the activity characteristics of 18β-glycyrrhetinic acid (18β-GA) and anthraquinone compounds (rhein and emodin), reduce toxicity, and explore the structure-activity relationship (SAR) of anthraquinones, 18β-GA-anthraquinone ester compounds were synthesized by one-step organic synthesis. The products were separated and purified by HPLC and characterized by NMR and EI-MS. It was finally determined as di-18β-GA-3-rhein ester (1, New), GA dimer (2, known), 18β-GA-3-emodin ester (3, known), and di-18β-GA-1-emodin ester (4, new). The MIC of three reactants and four products against Escherichia coli and Staphylococcus aureus were detected invitro. Its developmental toxicity and cardiotoxicity were assessed using zebrafish embryos. The experimental results showed that rhein had the best antibacterial activity against Staphylococcus aureus with MIC50 of 2.4 mM, and it was speculated that -COOH, -OH, and intramolecular hydrogen bonds in anthraquinone compounds would enhance the antibacterial effect, while the presence of-CH3 might weaken the antibacterial activity. Product 1 increased the hatching rate and survival rate of zebrafish embryos and reduced the malformation rate and cardiomyocyte apoptosis. This experiment lays the foundation for further studying the SAR of anthraquinones and providing new drug candidates.

Novel theranostic wounds dressing based on pH responsive alginate hydrogel/graphene oxide/levofloxacin modified silk

Integrating pH sensor with controlled antibiotic release is fabricated on silk to create a theranostic wound dressing. Alginate (ALG) hydrogel and graphene oxide (GO) loaded with levofloxacin (LVX) and a pH indicator are applied to fabricate a pH-responsive theranostic wound dressing. The modified silk color changes from yellow to green in response to elevated skin pH, indicating the skin infection. The semi-quantitative analysis was conducted using ImageJ, revealing significant color changes across the wide range. At elevated pH levels, the ionization of the COOH bonds within ALG induces repulsion among the COO− groups, thereby accelerating the release of the incorporated drug compared to release under lower pH. At an infected pH of 8, ALG hydrogel triggers LVX releasing up to 135.86 ± 0.3 µg, while at a normal pH of 7, theranostic silk releases 123.13 ± 0.26 µg. Incorporating GO onto silk fibers enhances LVX loading and sustains LVX release. Furthermore, these modified silks possess antimicrobial abilities without causing irritation or allergies on the human skin. This theranostic silks represents a major step forward in smart wound care, introducing a versatile platform of smart wound care.

Effect of carbon quantum dots doping on structural, optical, and antibacterial properties of barium tungstate nanocomposite material

Local bacterial infection remains an increasingly severe threat to human health worldwide, and infection control is still a challenging task. Carbon Quantum Dots (CQSs) and barium tungstate show antibacterial properties. CQDs doped Barium Tungstate (BaWO4) are synthesized by using a hydrothermal route and their optical and antimicrobial activities against the Gram-positive bacteria staphylococcus aureus and optical properties were investigated. The UV–Vis reveals a shift in the bandgap from 3.62 eV to 2.93 eV due to doping of CQDs in BaWO4. The structure of the CQDs/BaWO4 were studied by XRD, which shows CQDs doped BaWO4 samples possess tetragona4 werelite structure with the preferred orientation of (112) identified by XRD at 26° having crystallite size ∼ 31 nm. Nanocomposite BaWO4/CQDs exhibit a spherical-like shape and are composed of Ba, O, W and C according to the design of the experiment. Zeta sizer of CQDs by DLS shows the size of CQDs is 7.65 nm. The FT-IR shows the presence of functional groups in doped material like CC, CO, and COOH bonds which indicate that the C-dots are functionalized with epoxy, carbonyl, hydroxyl, and carboxylic acid groups. Their elemental composition and surface morphology were studied by EDS which shows the percentage variation of CQDs in BaWO4, SEM results show the change in shape of the sample by adding CQDs to BaWO4. The TEM image proves the presence of doped material in the BaWO4. The PL spectra reveals the emission spectra shift towards a higher wavelength and absorption increases. The qualitative analysis shows the antimicrobial activity and enlargement of the inhibition zone and quantitative analysis confirms it.

Reduction of formaldehyde emission from urea-formaldehyde resin by maleated nanolignin

In the present work, urea-formaldehyde (UF) resin was modified by maleic anhydride-modified nanolignin. For this purpose, nanolignin was prepared by an acidic method and then different ratios of virgin lignin, nanolignin and maleated nanolignin (10, 20 and 30 wt%) were added to the UF resin during its synthesis. The synthesized resins were then used in plywood panels manufacturing. The physicochemical and thermal properties of the prepared resins were determined. Formaldehyde emission, water absorption and shear strength of the plywood panels bonded with the modified resins were also measured according to the relevant standards methods. FTIR analysis indicated that the peak corresponding to O–H was decreased by the treatment of nanolignin with maleic anhydride. The intensity of the 2800 cm−1, 1200 cm−1 and 1700 cm−1 bands related to respectively C–O, CC and COOH bonds also increased in maleic anhydride-treated nanolignin. Based on the physicochemical results obtained, the modification of nanolignin by maleic anhydride accelerates the gelation time and increases the viscosity of the lignin-urea-formaldehyde (LUF) resin compared to when virgin nanolignin was used. DSC analysis shows that the addition of maleated nanolignin significantly decreases the curing temperature of the LUF resin. Based on panel analysis results, lower formaldehyde emission and higher mechanical strength and dimensional stability were obtained by treating nanolignin with maleic anhydride.

In situ encapsulated Co3O4 nanoparticles into self-catalyzed grown CNTs for efficient CO2 conversion

Co3O4-based catalysts emerged as promising candidates for electrocatalytic CO2 reduction reaction (eCO2RR), while the unclear active sites and poor stability are challenging for the application of Co3O4 as an electrocatalyst. Here, we developed a feasible method to in situ encapsulate Co3O4 nanoparticles (NPs) into self-grown CNTs. Co3O4 NPs were elaborately controlled to terminate with the occupation Co2+Th/Co3+Oh sites (with Co2+ and Co3+ in the center of tetrahedral/octahedral cells). The well-dispersed Co atoms derived from ZIF-67 catalyzed the in situ assembly of CNTs, allowing controlled oxidation and growth into Co3O4 nanoparticles spatially confined by CNTs, resulting in Co3O4 highly-dispersed into hollow CNTs and well-protected. The enhanced electrocatalytic performance of Co2+Th was revealed with an onset potential of −0.24 V, and the CO production rate (131 μmol/s·g·cm2, −0.85 V vs. RHE) on Th-Co3O4/CNTs (exposed with Co2+Th sites) is 3.1 times of that on Oh-Co3O4/CNTs (exposed with Co3+Oh sites). DFT calculations demonstrated a significant reduction in the rate-limiting activation barrier of CO2, and Co2+Th was proved to be more active than Co3+Oh with elongated *CO-OH bonds. In situ ATR-SEIRAS confirmed that the enhanced CO2 adsorption and rapid formation of *COOH on Th-Co3O4/CNTs were key factors leading to efficient CO production. This work introduced a clear understanding of the eCO2RR performance of Co2+Th/Co3+Oh sites, along with a feasible approach for catalyst construction and protection.

Unveiling the Reduction Mechanism of Pu(IV) by Acetaldoxime.

The separation of plutonium (Pu) from spent nuclear fuel was achieved by effectively adjusting the oxidation state of Pu from +IV to +III in the plutonium uranium reduction extraction (PUREX) process. Acetaldoxime (CH3CHNOH) as a free salt reductant can rapidly reduce Pu(IV), but the reduction mechanism remains indistinct. Herein, we explore the reduction mechanism of two Pu(IV) ions by one CH3CHNOH molecule, where the second Pu(IV) reduction is the rate-determining step with the energy barrier of 19.24 kcal mol-1, which is in line with the experimental activation energy (20.95 ± 2.34 kcal mol-1). Additionally, the results of structure and spin density analyses demonstrate that the first and second Pu(IV) reduction is attributed to hydrogen atom transfer and hydroxyl ligand transfer, respectively. Analysis of localized molecular orbitals unveils that the reduction process is accompanied by the breaking of the Pu-OOH bond and the formation of the OOH-H and C-OOH bonds. The reaction energies confirm that the reduction of Pu(IV) by acetaldoxime is both thermodynamically and kinetically accessible. In this work, we elucidate the reduction mechanism of Pu(IV) with CH3CHNOH, which provides a theoretical understanding of the rapid reduction of Pu(IV).

Synthesis and Characterization of Activated Carbon/Alginate/Nanocellulose-Cu Composites

OPEFB is one source of natural fiber-based composites which have the potential to become activated carbon and nanocellulose. This study aims to synthesize and characterize the activated carbon/alginate/nanocellulose-Cu composite. The characterization used in this study is FTIR and PSA. The synthesis of activated carbon/alginate/nanocellulose-Cu composites began with a process of carbonization and activation with H3PO4 to produce Activated Carbon. Followed by a bleaching process with NaClO2 and a delignification process with Na2SO3 and NaOH to produce Nanocellulose. Alginate using commercial alginate. Furthermore, the three ingredients were mixed until homogeneous and put into a 0.1M CuSO4 solution to produce beads. The results of the characterization of characterization of PSA Nanocellulose obtained a particle size of 41.05 nm and the result of FTIR characterization on the activated carbon/alginate/nanocellulose-Cu composite contained the functional group OH group, triple C bond from stretching alkyne, C=C aromatic group, C-H alkane group, C-O group, the P=O stretching vibration of the P-O-C group and the alcohol OH group expressing the active carbon; there are functional groups of hydroxyl (OH), carboxyl, carbonyl, and C-O-C and –COOH bonds which represent alginate and there are OH functional groups, stretching C-H bonds, C-O stretching, stretching C-C, and β- glucosidic bonds between glucose units which indicate nanocellulose.

Synthesis and Characterization of Activated Carbon/Alginate-Cu Composites

OPEFB is one source of natural fiber-based composites which have the potential to become activated carbon. This study aims to synthesize and characterize the activated carbon/alginate -Cu composite. The characterization used in this study is FTIR. The results of this study The synthesis of activated carbon/alginate -Cu composites began with a process of carbonization and activation with H3PO4 to produce Activated Carbon. Alginate using commercial alginate. Furthermore, the three ingredients were mixed until homogeneous and put into a 0.1M CuSO4 solution to produce beads. The characterization of FTIR characterization on the activated carbon/alginate-Cu composite contained the functional group OH group, triple C bond from stretching alkyne, C=C aromatic group, C-H alkane group, C-O group , the P=O stretching vibration of the P-O-C group and the alcohol OH group expressing the active carbon; there are functional groups of hydroxyl (OH), carboxyl, carbonyl, and C-O-C and –COOH bonds which represent alginate and there are OH functional groups, stretching C-H bonds, C-O stretching, stretching C-C. The KALg Cu13 sample had a peak at a wavelength of 2838.79 Cm-1 Where the four samples show the presence of C≡N groups.

Direct synthesis of oxalic acid via oxidative CO coupling mediated by a dinuclear hydroxycarbonylcobalt(III) complex

Oxidative coupling of CO is a straightforward and economic benign synthetic route for value-added α-diketone moiety containing C2 or higher carbon compounds in both laboratory and industry, but is still undeveloped to date. In this work, a rare coplanar dinuclear hydroxycarbonylcobalt(III) complex, bearing a Schiff-base macrocyclic equatorial ligand and a μ-κ1(O):κ1(O’)-acetate bridging axial ligand, is synthesized and characterized. The Co(III)-COOH bonds in this complex can be feasibly photocleaved, leading to the formation of oxalic acid. Moreover, the light-promoted catalytic direct production of oxalic acid from CO and H2O using O2 as the oxidant with good selectivity (> 95%) and atom economy at ambient temperature and gas pressure based on this dicobalt(III) complex have been achieved, with a turnover number of 38.5. The 13C-labelling and 18O-labelling experiments confirm that CO and H2O act as the sources of the -COOH groups in the dinuclear hydroxycarbonylcobalt(III) complex and the oxalic acid product.

Effects of Ca-Compounds on the Gases Formation Behavior during Molten Salts Thermal Treatment of Bio-Waste

Bio-waste utilization is essential, and pyrolysis is a prominent way for its effective utilization. However, the gradual accumulation of ash compounds in the intermediate products probably affects the thermal conversion characteristics of bio-waste. In the present study, beech wood and disposable chopsticks were selected as bio-waste samples. The effects of typical ash components (Ca-compounds) on volatile formation behavior were investigated during the molten salts thermal treatment of bio-waste. Results demonstrated that about 80% mass of initial bio-waste was gasified into the volatiles at 300 °C. The introduction of Ca-compounds in the molten salts slightly decreased the total yield of gaseous products. More specifically, Ca2+ could improve the generation of CO2 and suppress the generation of other gases (CO, H2, and CH4), and this is accompanied by a reduction in the low heating value (LHV) of the gases. The possible reason is that Ca2+ might act on the -OH bonds, phenyl C-C bond, methoxy bond and carboxylic acid -COOH bonds of the bio-waste to promote CO2 release. In contrast, the introduction of CO32− and OH- tended to relieve the inhibition effect of Ca2+ on the generation of H-containing gases. Meanwhile, the introduction of Ca2+ can promote the conversion of bio-waste into liquid products as well as increase the saturation level of liquid products. Moreover, as a vital form of carbon storage, CO2 was found to be abundant in the pyrolysis gases from molten salts thermal treatment of bio-waste, and the concentration of CO2 was much higher than that of direct-combustion or co-combustion with coal. It’s a promising way for bio-waste energy conversion as well as synchronized CO2 capture by using molten salts thermal treatment, while the introduction of small amounts of Ca-compounds was found to have no significant effect on the change of CO2 concentration.

Spontaneous combustion characteristics and mechanism of water-immersed and air-dried brown coal

ABSTRACT To reveal the influential laws and mechanism of water immersion on the spontaneous combustion traits of lignite in the low-temperature oxidation stage. Raw coal (HL), water-immersed for 30 days (HL-S30), 90 days (HL-S90) and 150 days (HL-S150), were taken as the research objects. The pore evolution characteristics and functional group migration law of coal were explored by Scanning Electron Microscopy (SEM), Low-temperature Nitrogen Adsorption Test (LNAT) and Fourier Transform Infrared Spectroscopy (FTIR). The low-temperature oxidation procedure was simulated by Programmed Heating Test (PHT), and the gas release characteristics, exothermicity and ultimate spontaneous combustion parameters of the relic coal were compared. These findings demonstrated that the discriminant indexes of spontaneous combustion tendency of four specimens change periodically with temperature, but generally the spontaneous combustion intensity of HL-S30 and HL-S150 is greater than HL, and HL-S90 is the least. The micro reasons for increasing oxidation activity of HL-S30 and HL-S150 are as follows: the number of micropores of water-immersed coal is almost 3 ~ 4 times that of HL, and the pores expanded with immersion which helps to enhance the adsorption of oxygen; the content of broken aromatic hydrocarbon -C = C- reached 50%, the total amount of hydroxy -OH decreased to 2/3 of HL, while the content of carboxyl -COOH and ether-oxygen bond -C-O- of active group doubled which are beneficial to accelerate the process of free radical chain reaction, and promote the gas release and the temperature of residual coal to reach the ignition point. The research findings enrich the basic theory of spontaneous combustion traits of water-impregnated coal, which help reduce the fire accidents and hidden dangers in actual production.

Cephalexin Adsorption by Acidic Pretreated Jackfruit Adsorbent: A Deep Learning Prediction Model Study

Cephalexin (CFX) residues in the environment represent a major threat to human health worldwide. Herein we investigate the use of novel approaches in deep learning in order to understand the mechanisms and optimal conditions for the sorption of cephalexin in water onto an acidic pretreated jackfruit peel adsorbent (APJPA). The interaction between the initial concentration of CFX (10–50 mg/100 mL), APJAP dosage (3–10 mg/100 mL), time (10–60 min), and the pH (4–9), was simulated using the one-factor-at-a-time method. APJPA was characterized by FESEM images showing that APJPA exhibits a smooth surface devoid of pores. FTIR spectra confirmed the presence of -C-O, C–H, C=C, and -COOH bonds within the APJPA. Maximum removal was recorded with 6.5 mg/100 mL of APJAP dosage, pH 6.5, after 35 min and with 25 mg/100 mL of CFX, at which the predicted and actual adsorption were 96.08 and 98.25%, respectively. The simulation results show that the dosage of APJAP exhibits a high degree of influence on the maximum adsorption of CFX removal (100%) between 2 and 8 mg dose/100 mL. The highest adsorption capacity of APJAP was 384.62 mg CFX/g. The simulation for the effect of pH determined that the best pH for the CFX adsorption lies between pH 5 and 8.

High-Pressure-Limit and Pressure-Dependent Rate Rules for Unimolecular Reactions Related to Hydroperoxy Alkyl Radicals in Normal Alkyl Cyclohexane Combustion. 1. Concerted HO2 Elimination Reaction Class and β-Scission Reaction Class.

The reactions of the concerted HO2 elimination from alkyl peroxy radicals and the β-scission of the C-OOH bond from hydroperoxy alkyl radicals, which lead to the formation of olefins and HO2 radicals, are two important reaction classes that compete with the second O2 addition step of hydroperoxy alkyl radicals, which are responsible for the chain branching in the low-temperature oxidation of normal alkyl cycloalkanes. These two reaction classes are also believed to be responsible for the negative temperature coefficient behavior due to the formation of the relatively unreactive HO2 radical, which has the potential to inhibit ignition of normal alkyl cycloalkanes. In this work, the kinetics of the above two reaction classes in normal alkyl cycloalkanes are studied, where reactions in the concerted elimination class are divided into subclasses depending upon the types of carbons from which the H atom is eliminated and the positions of the reaction center (on the alkyl side chain or on the cycle), and the reactions in the β-scission reaction class are divided into subclasses depending upon the types of the carbons on which the radical is located and the positions of the reaction center. Energy barriers by using quantum chemical methods at the CBS-QB3 level, high-pressure-limit rate constants by using canonical transition state theory, and pressure-dependent rate constants at pressures from 0.01 to 100 atm by using Rice-Ramsberger-Kassel-Marcus/Master Equation theory are calculated for a representative set of reactions from methyl cyclohexane to n-butyl cyclohexane in each subclass, from which high-pressure-limit rate rules and pressure-dependent rate rules for each subclass are derived from the average rate constants of reactions within each subclass. A comparison of the rate constants for the reactions in the two reaction classes calculated in this work is made with the rate constants of the same reactions from available mechanisms published in the literature, where most of the rate constants are approximately estimated from analogous reactions in alkanes or small alkyl cyclohexanes, and it is found that a large difference may exist between them, indicating that the present work, which provides more accurate kinetic parameters and reasonable rate rules for these reaction classes, can be helpful to construct higher-accuracy mechanism models for normal alkyl cyclohexane combustion.

Studies of physicochemical characteristics of organoclay with carboxydecyltriethylammonium chloride ion

ABSTRACT This study used the soil representative of Taitung in Taiwan, Santai (St) series soil, as the catalyst carrier and exchanged arboxydecyltriethylammonium chloride (CDTEA) onto it through ion exchange, forming nano-level St-CDTEA organoclay via surface modification and high-temperature sintering. The physical and chemical properties of the St-CDTEA organoclay were then studied via a series of physical and chemical experiments.First, an analysis of the basic properties of St series soil shows that it does not have a high organic matter content because it is affected by either rainfall erosion or intensive farming, which causes a decrease in organic matter after it is consumed or lost. The Fourier-transform infrared spectroscopy (FT-IR) analysis suggests that compared with the unmodified St series soil, C-H bonds are found between 2900 cm-1 and 2850 cm-1 and COOH bond around 1750 cm-1 in St-CDTEA organoclay. A field emission scanning electron microscope (FE-SEM) analysis shows the formation of a crystal structure on the surface of the St-CDTEA organoclay because St series soil contains a larger amount of smectite and the structure of the St-CDTEA organoclay absorbs a significant amount of CDTEA molecules (the molecular structure of CDTEA contains three ethyls) after high-temperature sintering.

Modification of thin carbon films by UVc light

We modified single- and few-layer nano-sized graphene films deposited by pulsed laser deposition (PLD) on ∼300-nm-thick SiO2/Si substrates. The samples were irradiated by a UVC lamp (wavelength of 254 nm) for 15 and 30 minutes in air atmosphere. The light was directed almost parallel (about 2 - 2.5 arcdeg declination angle) to the films’ surface. The influence of the modification was evaluated by ellipsometry and X-ray photoelectron and Raman spectroscopies. The results showed that the irradiation caused an increase of the C-O/C-OH bond and a decrease or the complete disappearance of the -C=O/-COOH bond. The structural quality of the graphene films was improved moderately after a 15-min UVC treatment.

Immobilization of Catalase Using PAES-C Polymer for Wastewater Biological Treatment Research

PAES-C polymer modified by glutaraldehyde (GA) was selected to immobilize the catalase. Infrared spectrum analysis and 1H NMR test the presence of - COOH bond in PAES-C, which favored the cross-linking of PAES-C with catalase. The SEM image showed that its surface had a porous structure, which increased its surface area and provided more active sites for the immobilization of catalase. Indeed, the influence of various factors including GA mass concentration, modification time of GA and carrier, cross-linking time of modified carrier and catalase on the immobilization capacity were deeply investigated. In particular, the achieved optimal conditions for immobilization of catalase were as following: GA mass concentration was set at 1.0wt%, GA modification time was 1.0 h, and the binding time between the modified carrier and the enzyme was 1.0 h. Herein, the findings in this work revealed that PAES-C polymer might be one of the promising candidates for wastewater biological treatment and immobilization of other enzyme.

PVA/PAA based electrospun nanofibers with pH-responsive color change using bromothymol blue and on-demand ciprofloxacin release properties

In this study, a nanofibrous mat of polyvinyl alcohol (PVA) and polyacrylic acid (PAA) loaded with pH-responsive dye bromothymol blue (BTB) and antibacterial drug ciprofloxacin was fabricated by using the electrospinning method. The nanofibrous mats were crosslinked by heat treatment to enhance stability in an aqueous medium. The pH-responsive property of PAA and halochromic BTB were utilized to functionalize the mats for on-demand ciprofloxacin release and wound condition monitoring, respectively. The yellowish color of the nanofiber mat changed to green and blue at pH 7 and 8.5 which simulates wound condition. The ionization of –COOH bonds of PAA at higher pH causes repulsion among -COO- which causes incorporated drug to release faster than the release at lower pH condition. The release of the drug doubled, from 15% to 33%, within 2 h at a higher pH release medium. The swelling of the nanofibrous mats was 1378% at pH 7 and 1565% at pH 8.5 environment compared to 545% at pH 4 environment. The water vapor transmission rates (WVTR) of the nanofibrous mats were higher than the required WVTR value for efficient wound healing. Antibacterial drug ciprofloxacin enhanced the functionality of the potential wound dressing by showing excellent antibacterial property against both gram-positive and gram-negative bacteria.

Evaluation of degradation of pigments formed during garlic discoloration in different pH

The specific chemical bond changes of green pigment formed in garlic discoloration were investigated in our study. Multiple analysis methods were used in the degradation of pigment, including ultraviolet–visible (UV–Vis) spectrophotometry, attenuated total reflection Fourier transform infrared (ATR-FTIR) and Fourier transform infrared near infrared (FT-NIR). Green pigments were treated at 40 °C for 7 days in the pH range of 5.0–8.0. Principal component analysis of the ATR-FTIR and FT-NIR spectra indicated the similarities and differences during pigment degradation. It was found that the degradation degree of green pigments in a solution with pH 5.0 was the lowest. Changes in the absorptions of CO, COO−, CN, CN, OCOCH, COC, COOH, and NH bonds vibrations are attributed to the decomposition of the pigments. The absorption at 5170 cm−1 (NH bond first overtone) and 4871 cm−1 (OCH stretching) correlated to pigment degradation were confirmed by FT-NIR spectra. One proposed pathway of the pigment decomposition was explored.

Light to enhance CO2 capture by a flexible heterostructure

Based on photovoltaic effect and annealing,a flexible liquid-solid heterostructure of PANI and PyBIG based on carbon nano-tube (CNT) is prepared to drive the low temperature (343 K–363 K) CO2 desorption intensified by the light. By the DFT and experiment, the reaction mechanism is determined as electron and hole produced by the light, deprotonization, electron and hole transport, and CO2 release. The flexible characteristic of the heterostructure is identified as interface slip, transport channel change and stretching phenomenon in the nano-scale. The repelling effect between water molecule and oil molecule enhances the −COO-H bond breaking and -NH2 production. The stretching phenomenon makes the electron and hole transport along the line rather than in a circle. The CO2 desorption reaction energy is determined as low as 11.42 kJ/mol. The energy consumption of heterostructure to drive the CO2 desorption at 343 K–363 K is determined as 0.89 GJ/t-1.12 GJ/t, which is much lower than the conventional 2.2 GJ/t-2.8 GJ/t.