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• 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.

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.

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.

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.

Abstract: Different molecular weight lignosulfonates were acquired by ultrafiltration and their adsorption behavior on dimethomorph powder were investigated. The results showed that as the molecular weight of lignosulfonates increased the adsorption amounts increased and the adsorption processes were driven by van der Waals forces and hydrophobic effects. The adsorption isotherms were fitted well by Langmuir model. Relations of adsorption amounts and zeta potentials with particle size of dimethomorph particles were established to disclose the dispersing mechanism of dimethomorph suspensions. The average particle sizes were determined by zeta potentials rather than adsorption amounts, which confirmed the dispersing mechanisms were electrostatic repulsive forces. [Copyright &y& Elsevier]

X-ray photoelectron spectroscopy (XPS) was adopted to evaluate steric repulsive force in the aqueous dispersion system of dimethomorph powder with lignosulfonate (LS). The calculation of adsorption layer thickness (ALT) of LS on dimethomorph based on the relative intensity of the N 1s peak from XPS was presented. The ALT was correlated with the volume-based average particle size (VAPS) of dimethomorph suspensions that indicated the dispersion efficiency of LS. As expected, VAPS decreased linearly with growing ALT; namely, the dispersion efficiency of LS increased with growing ALT except Kinsperse. Zeta potential experiments demonstrated that the dominant electrostatic repulsive forces controlled the particle dispersing mechanism when Kinsperse was used as dispersant. The positive-going relationship of dispersion efficiency of LS with ALT confirmed that it would be feasible to use ALT to evaluate steric repulsive forces in the dispersion system of dimethomorph with LS, and that would lead to a potential utilization in other dispersion systems.