Search

• Dual S-scheme IO/Pedot/IS was designed to degradate lignin and antibiotic. • Dual S-scheme increase electron density and carrier transport rate. • h + conductivity of Pedot effectively mitigated the photocorrosion. • IO/Pedot/IS achieved 85.8% mineralization of lignin. Superior photo-mineralization of pollutants, outstanding charge separation efficiency and exceptional photostability of catalysts constitute three pivotal factors for the effective photodegradation of organic pollutants. In this study, a dual S-scheme In 2 O 3 /Pedot/In 2 S 3 (IO/Pedot/IS), inspired by natural photosynthesis, was successfully synthesized for the degradation of lignin and antibiotics. The resulting exceptional semiconductor contact creates a dual-interface electric field on Pedot, facilitating multi-channel charge transport and enhancing charge separation efficiency. The establishment of the dual S-scheme heterojunction raised the reduction-oxidation potential of the type-II In 2 O 3 / In 2 S 3. When subjected to 5 W LED irradiation for 60 min, IO/Pedot-2/IS demonstrated a remarkable mineralization rate of 85.8% for sodium lignosulfonate (SL), surpassing the 53.7% mineralization rate achieved by IO/IS. Furthermore, the degradation efficiency for tetracycline (TC) and ciprofloxacin (CIP) reached 91% and 88%, respectively. Crucially, the hole (h +) conductivity of Pedot efficiently alleviated the photocorrosion of sulfide, ensuring robust cyclic stability. Experimental simulations of natural photocatalysis showcased the exceptional versatility and applicability of IO/Pedot/IS. In-depth analysis led to the proposal of a potential photodegradation pathway for lignin, based on the intermediates detected through liquid chromatography-mass spectrometry (LC-MS). Overall, this study presents an effective strategy for the efficient photocatalytic treatment of organic pollutants. [Display omitted] [ABSTRACT FROM AUTHOR]

Steric repulsive force is the main dispersion force between cement particles. In order to improve the dispersibility of polycarboxylate superplasticizers (PCEs), we designed and synthesized a new Y-type macromonomer (YPEG) with a molecular weight of Mw= 4100 Da. A long side chain-branched polycarboxylate superplasticizer (YPCE) was successfully synthesized by employing YPEG. Several common comb PCEs having the same side chain density but different lengths, such as PCE2400 and PCE4000, are employed to compare with YPCE for evaluating the dispersion performance. The results show that YPCE has a more excellent dispersion performance than the common PCEs under different water–cement ratios. Additionally, YPCE shows stronger water reduction for concrete. Furthermore, a dynamic light scattering study elucidates that YPCE can increase the adsorbed layer thickness from 5.6 to 7.9 nm, thus forming stronger steric hindrance. Simulations using molecular dynamics are conducted to investigate the influence of the conformational transformation of PCEs from comb-type to Y-type on the adsorption configuration and radius of gyration (Rg) of PCEs on calcium silicate hydrate surface. It is observed that the side chain of YPCE remains in an extended state, and Rgfluctuates little during the fitting process. This study provides a new strategy to enhance the steric hindrance of PCEs.

The introduction of metal vacancies into n-type semiconductors could efficiently construct intimate contact interface p–n homojunctions to accelerate the separation of photogenerated carriers. In this work, a cationic surfactant occupancy method was developed to synthesize an indium-vacancy (VIn)-enriched p–n amorphous/crystal homojunction of indium sulfide (A/C-IS) for sodium lignosulfonate (SL) degradation. The amount of VInin the A/C-IS could be regulated by varying the content of added cetyltrimethylammonium bromide (CTAB). Meanwhile, the steric hindrance of CTAB produced mesopores and macropores, providing transfer channels for SL. The degradation rates of A/C-IS to SL were 8.3 and 20.9 times higher than those of crystalline In2S3and commercial photocatalyst (P25), respectively. The presence of unsaturated dangling bonds formed by VInreduced the formation energy of superoxide radicals (•O2–). In addition, the inner electric field between the intimate contact interface p–n A/C-IS promoted the migration of electron–hole pairs. A reasonable degradation pathway of SL by A/C-IS was proposed based on the above mechanism. Moreover, the proposed method could also be applicable for the preparation of p–n homojunctions with metal vacancies from other sulfides.

Metal–organic frameworks (MOFs) have become promising accommodation for enzyme immobilization in recent years. However, the microporous nature of MOFs affects the accessibility of large molecules, resulting in a significant decline in biocatalysis efficiency. Herein, a novel strategy is reported to construct macroporous MOFs by metal competitive coordination and oxidation with induced defect structure using a transition metal (Fe2+) as a functional site. The feasibility of in situ encapsulating β-glucosidase (β-G) within the developed macroporous MOFs endows an enzyme complex (β-G@MOF-Fe) with remarkably enhanced synergistic catalysis ability. The 24 h hydrolysis rate of β-G@MOF-Fe (with respect to cellobiose) is as high as approximately 99.8%, almost 32.2 times that of free β-G (3.1%). Especially, the macromolecular cellulose conversion rate of β-G@MOF-Fe reached 90% at 64 h, while that of β-G@MOFs (most micropores) was only 50%. This improvement resulting from the expansion of pores (significantly increased at 50–100 nm) can provide enough space for the hosted biomacromolecules and accelerate the diffusion rate of reactants. Furthermore, unexpectedly, the constructed β-G@MOF-Fe showed a superior heat resistance of up to 120 °C, attributing to the new strong coordination bond (Fe2+–N) formation through the metal competitive coordination. Therefore, this study offers new insights to solve the problem of the high-temperature macromolecular substrate encountered in the actual reaction.

Fast-response artificial phototropic materials are a promising tool for solar energy utilisation, yet their preparation remains challenging. Herein, we report the so-called photothermal domino strategy for constructing fast-response artificial phototropic materials. In this strategy, photothermal generation, heat conduction and thermal actuation are sequentially optimised by a coordination effect. For the first time, lignin-based organic radicals boosted by this coordination effect are used to significantly enhance photothermal conversion. Interfacial coordination bonds between lignin and an elastomer matrix promote interfacial heat conduction. Light-stimulated thermal actuation is significantly improved by coordination-assisted mechanical training. The prepared biomimetic phototropic material exhibits excellent phototropic ability, with a 2.5 s light-tracking process, showing great application potential for efficient solar energy utilisation. This strategy shows great significance for fabricating high-performance intelligent phototropic materials using widely available, green raw materials.

The photoreforming of lignocellulose is a novel method to produce clean and sustainable H2energy. However, the catalytic systems usually show low activity under ultraviolet light; thus, this reaction is very limited at present. Visible light-responsive metal-free two-dimensional graphite-phased carbon nitride (g-C3N4) is a good candidate for photocatalytic hydrogen production, but its activity is hindered by a bulky architecture. Although reported layered g-C3N4modified with active functional groups prepared by the chemical exfoliation enhances the photocatalytic activity, it lost the intrinsic structure and thus is not conducive to understand the structure–activity relationship. Herein, we report an intrinsic monolayer g-C3N4(∼0.32 nm thickness) prepared by nitrogen-protected ball milling in water, which shows good performance of photoreforming lignocellulose to H2driven by visible light. The exciton binding energy of g-C3N4was estimated from the temperature-dependent photoluminescence spectra, which is a key factor for subsequent charge separation and energy transfer. It is found that monolayer g-C3N4with smaller exciton binding energy increases the free exciton concentrations and promotes the separation efficiency of charge carriers, thereby effectively improving its performance of photocatalytic reforming of lignocellulose, even the virgin lignocellulose and waste lignocellulose. This result could lead to more active catalysts to photoreform the raw biomass, making it possible to provide clean energy directly from locally unused biomass.

The technical enzymatic hydrolysis lignin (EHL) and alkali lignin (AKL) were pretreated via alkaline depolymerization and organic solvent extraction process, respectively. The molecular weight of lignin was lowered and the molecular weight distribution was narrowed, while the content of phenolic hydroxyl group increased after the pretreatment of alkaline depolymerization or solvent extraction. The lignin extracted with ethyl acetate got the lowest molecular weight and highest phenolic hydroxyl group content, showing even better free radical scavenging ability than the commercial Irganox1010. Lignin/SBS elastomer composites were prepared with even dispersion of lignin in the SBS matrix with an average particle size close to 40 nm. It was demonstrated that the alkali lignin extracted with ethyl acetate showed the best improvement on the antioxidant performance of SBS and was comparable to that of Irganox1010 in the SBS elastomer, showing great application potential.

To solve the poor absorbance on ultraviolet A (UVA) radiations and dark color, alkali lignin (AL) was modified via atom transfer radical polymerization (ATRP) grafting of 2-4-benzoyl-3-hydroxyphenyl acrylate (BHA). The color of AL was whitened 86% and the UVA/UVB absorbance ratio of AL-g-BHA improved to 1.2, while the reported highest value was 0.9. The excellent UV-blocking performance of AL-g-BHA was demonstrated in sunscreen. Sun protection factor (SPF) value of the sunscreen containing 10 wt % of optimal AL-g-BHA reached 59. Nanoscale AL-g-BHA normal and reverse micelles (LBNM and LBRM) were fabricated to investigate the effect of microstructure on the sunscreen performance. When BHA chains were packed inside, the SPF value of sunscreen containing 10 wt % of LBNM decreased to 28. In contrast, the SPF value of sunscreen containing 10 wt % of LBRM with BHA chains distributing on the surface was up to 244. Both AL-g-BHA and corresponding micelles exhibited good biocompatibility.

The advancement of anti-tumor nanomedicines is restricted by the delivery efficiency owing to a lack of insight into the intratumoral delivery mechanism, especially traversing the biological barriers. Herein, we explore a new strategy focusing on controlling excessive high tumor interstitial fluid pressure (TIFP) caused by lymphatic lack, which hampers the convective diffusion of nanomedicines to the tumor center. We construct a “nano-lymphatic” system (DOX/g-C3N4/luminol@cytomembrane, DCL@M) based on graphitic carbon nitride (g-C3N4) for photocatalytic water splitting, which can decrease the volume of the tumor interstitial fluid to ameliorate the transfer resistance derived from the high TIFP. In the tumor microenvironment, lactic acid as a sacrificial agent in catalysis greatly promoted the water-splitting efficiency; thus, TIFP in the tumor tissue was reduced to 62.11%, causing an enhancement in blood perfusion to the tumor. The accumulation of the “nano-lymphatic” system (16.73%) in the tumor was 15.9- and 3.31-fold greater than those of free doxorubicin hydrochloride (DOX, 1.05%) and DOX/g-C3N4@cytomembrane (DC@M, 3.03%), respectively. The penetration efficiency of the “nano-lymphatic” system was 8.98% at the tumor center. The “nano-lymphatic” strategy produced reactive oxygen species associated with water splitting to suppress the tumor growth; thus, we define the strategy as hydrodynamic therapy, which provides a new avenue for nanomedicines in traversing biological barriers and achieves a better therapeutic effect.

Lignosulfonate (LS) had various influences on the enzymatic digestibility of lignocelluloses for the complicated structure of LS. The effect of the complex of LS and cationic surfactant cetyltrimethylammonium bromide (LS–CTAB) on the enzymatic digestibility of corn stover and Avicel was investigated in this study. The LS–CTAB catanionic surfactant could significantly improve the enzymatic digestibility of Avicel and corn stover from 42.1 and 24.3% to 62.3 and 56.2%, respectively. In addition, the effect of LS–CTAB with various molecular weights and sulfonation degrees of LS and varied alkyl chain lengths of CnTAB on the enzymatic digestibility of Avicel was further investigated to reveal that the mechanism of LS–CTAB enhanced the enzymatic digestibility of cellulose. LS adsorbed on cellulase aggregates and dispersed the aggregates to form the smaller and more hydrophilic LS–cellulase aggregates. CTAB neutralized the electronegative charge of LS–cellulase aggregates, improved the interaction between cellulase and cellulose, and enhanced the enzymatic digestibility of cellulose.

A lignin amphoteric surfactant and betaine could enhance the enzymatic hydrolysis of lignocellulose and recover cellulase. The effects of lignosulfonate quaternary ammonium salt (SLQA) and dodecyl dimethyl betaine (BS12) on enzymatic hydrolysis digestibility, ethanol yield, yeast cell viability, and other properties of high-solid enzymatic hydrolysis and fermentation of a corncob residue were studied in this research. The results suggested that SLQA and 1 g/L BS12 effectively improved the ethanol yield through enhancing enzymatic hydrolysis. SLQA had no significant effect on the yeast cell membrane and glucose fermentation. However, 5 g/L BS12 reduced the ethanol yield as a result of the fact that 5 g/L BS12 damaged the yeast cell membrane and inhibited the conversion of glucose to ethanol. Our research also suggested that 1 g/L BS12 enhanced the ethanol yield of corncob residue fermentation, which was attributed to the fact that lignin in the corncob adsorbed BS12 and decreased its concentration in solution to a safe level for the yeast.

Lignosulfonate (LS), one type of industrial lignin and natural macromolecular sun blocker, was applied to modify TiO2via one-pot hydrothermal esterification. The reaction mechanism and composite structure of LS@TiO2were investigated by DLS, TEM, AFM, TG, UV, FTIR, XPS, XRD, ESR, and contact angle measurements. The results show that the esterification modification occurred between the carboxyl groups of lignin and the hydroxyl groups on the surface of TiO2. Lignosulfonate of 3.4 wt % with a thickness of 13 nm effectively coated the normal TiO2, and the LS@TiO2composites were nanoscale with an average size of 119 nm. Hydroxylated TiO2particles were more reactive, and the contents of LS on TiO2were processed by 0.1 and 1 M HCl and increased to 5.0 wt % (LS@TiO2-0.1M) and 6.0 wt % (LS@TiO2-1M), respectively. Chemically coated LS not only improved the dispersibility of TiO2in the substrates, but also significantly boosted its UV-blocking ability. Therefore, TiO2@LS nanocomposites were applied as the sole active in the pure cream and the sunscreen performance was compared with that of TiO2. The sun protection factor (SPF) values of creams containing 5, 10, and 20 wt % LS@TiO2were 16, 26, and 48, respectively. They were 30–60% higher than those of the creams containing the same amount of TiO2. The sunscreen performance of LS@TiO2improved with LS content. The SPF value of pure cream containing 10 wt % LS@TiO2-1M reached 50+. The possible UV-blocking enhancement mechanism of LS@TiO2was also revealed. Preparation of LS@TiO2nanocomposites provides a facile and green way for value-added utilization of lignin biomass and highly efficient UV-blocking of nano-TiO2materials.

In situintegration of enzymes with covalent organic frameworks (COFs) to form hybrid biocatalysts is both significant and challenging. In this study, we present an innovative strategy employing deep eutectic solvents (DESs) to synergistically synthesize COFs and shield cytochrome c (Cyt c). By utilizing DESs as reaction solvents in combination with water, we successfully achieved rapid and in situencapsulation of Cyt c within COFs (specifically COF-TAPT-TFB) under ambient conditions. The resulting Cyt c@COF-TAPT-TFB composite demonstrates a remarkable preservation of enzymatic activity. This encapsulation strategy also imparts exceptional resistance to organic solvents and exhibits impressive recycling stability. Additionally, the enhanced catalytic efficiency of Cyt c@COF-TAPT-TFB in a photoenzymatic cascade reaction is also showcased.

Photocatalytic water splitting to hydrogen is a sustainable energy conversion method. However, there is a lack of sufficiently accurate measurement methods for an apparent quantum yield (AQY) and a relative hydrogen production rate (rH2) at the moment. Thus, a more scientific and reliable evaluation method is highly required to allow the quantitative comparison of photocatalytic activity. Herein, a simplified kinetic model of photocatalytic hydrogen evolution was established, the corresponding photocatalytic kinetic equation was deduced, and a more accurate calculation method is proposed for the AQY and the maximum hydrogen production rate vH2,max. At the same time, new physical quantities, absorption coefficient kLand specific activity SA, were proposed to sensitively characterize the catalytic activity. The scientificity and practicality of the proposed model and the physical quantities were systematically verified from the theoretical and experimental levels.

Sulfonated-acetone-formaldehyde (SAF) was grafted with alkali lignin (AL) to prepare grafted sulfonated-acetone-formaldehyde lignin (GSL). Considering the rich phenolic hydroxyl groups in GSL, we detected a hole mobility of 2.27 × 10–6cm2V–1s–1with GSL as a hole transport material by space-charge-limited current model. Compared with nonconjugated poly(styrene sulfonic acid), GSL was applied as p-type semiconductive dopant for PEDOT to prepare water-dispersed PEDOT:GSL. PEDOT:GSL shows enhanced conductivity compared with that of PEDOT:PSS. Simultaneously, the enhanced open-circuit voltage, short-circuit current density, and fill factor are achieved using PEDOT:GSL as a hole extract layer (HEL) in sandwich-structure inverted perovskite solar cells. The power conversion efficiency is increased to 14.94% compared with 12.6% of PEDOT:PSS-based devices. Our results show that amorphous GSL is a good candidate as dopant of PEDOT, and we provide a novel prospective for the design of HEL based on lignin, a renewable biomass and phenol derivatives.

Stable aqueous graphene suspensions (AGSs) with high concentration and little defect were prepared through exfoliating from graphite by sonication with the aid of sodium lignosulfonate (SL). The concentration of AGS (CG) dispersed by the modified SL can reach up to 13.5 g/L at an initial graphite concentration of 200 g/L, which is substantially higher than those reported previously. Four SL fractions with different molecular weight (Mw) and sulfonic acid group prepared by ultrafiltration of a commercial SL were applied to evaluate the dispersing mechanism and the effects of SL molecular structure on the AGS. The maximum concentration of AGS dispersed by the SL fractions increased with the decline of Mw and the ion strength of SL solutions and with the increase of sulfonic acid group. The CGcan be further improved through improving the hydrophobicity of SL by either covalent or noncovalent modification. It was found that the CGwas proportional to the zeta potentials, which suggested that electrostatic repulsion played a crucial role in the dispersion process of AGS. Meanwhile, the obtained high-concentration AGS dispersed by SL is nontoxic, which facilitates it as a promising material for application in the biomedical field.

The corrosion and scale inhibition properties of sodium lignosulfonate (SL) were investigated by determining the corrosion and scale inhibition efficiency, the polarization curve, the residual turbidity, and the polymorph of calcium carbonate (CaCO3) scale. It is found that, to a certain degree, SL has a positive corrosion inhibition effect at the higher dosage, whereas it accelerates the corrosion of carbon steel at the lower dosage. SL also has a good dispersibility to CaCO3, causing a small CaCO3scale inhibition efficiency of maximum value of 2.5% at a dosage of 50 mg/L SL. Because there exist intrinsic limitations of SL without modification as a water treatment agent in a cooling water circulation system, the original SL was further chemically modified by grafting with acrylic acid monomer. The modified SL increases its negative charge density and hence an adsorption quantity on the active anodic sites in the electrochemical reaction. The corrosion inhibition efficiency of modified SL is consequently greatly improved. Compared with original SL, the scale inhibition effect of modified SL is better due to its contribution to distortion of the CaCO3crystal lattice. The modified SL may be a potentially useful corrosion and scale inhibitor in a cooling water system.