Nano zero-valent iron (NZVI) is a promising material for reducing chlorophenol pollutants and remediating low C/N water bodies. However, NZVI particles tendency to aggregate and limited ability to supply electrons to microorganisms constrain its practical applications. In this study, in situ loading of NZVI onto pretreated stalks (PSS/NZVI) was proposed. Results show that pretreated stalks (PSS) effectively disperse NZVI. Additionally, PSS serves as a carbon source, promoting denitrification during the remediation of simulated low C/N water bodies when PSS/NZVI is added into sediment. Compared with the control sample, total nitrogen (TN) removal efficiency in the supernatant and interstitial water of the sediment increased from 64.5% and 71.4-96.3% and 94.7%, respectively. Notably, during remediation, NZVI in PSS/NZVI combines with P to remove total phosphorus (TP) as Fe-P precipitates. Furthermore, PSS/NZVI significantly enhances sediment microbial activity, enabling the system to withstand subsequent pollution shocks. This study provides an environmentally benign method to improve NZVI dispersity. Moreover, through simulated water bodies applications, the practical value of PSS/NZVI was demonstrated, improving the degradation efficiency of TN, TP, and 2,4-dichlorophenol (2,4-DCP) in low C/N water bodies, proving that the combination of zero-valent iron and waste stalk carbon sources is feasible for remediating chlorophenol-polluted low C/N water bodies. This research enhances the practical value of NZVI for remediating low C/N water bodies.

A new two-dimensional (2D) lanthanide metal-organic framework [Eu-2(ATA)(3)(phen)(2)](n) (Eu-MOF, H(2)ATA = 2-amino terephthalic acid, phen = 1,10-phenanthroline) was successfully self-assembled via a simple solvothermal method. Then D-camphoric acid (D-Cam) was grafted onto Eu-MOF by post-synthetic modification (PSM) through a mechanochemical approach, successfully fabricating the chiral material Eu-MOF-D-Cam. Remarkably, this modification not only significantly enhanced the luminescent properties but also introduced the chiral sites for enantioselective sensing of mandelic acid (MA) enantiomers. The enantioselectivity factor alpha (alpha = K-SV(R-MA)/K-SV(S-MA)) of Eu-MOF-D-Cam was 2.56. These findings establish Eu-MOF-D-Cam as a promising photoluminescent sensor for chiral discrimination of R/S-MA enantiomers.

This work reported the (3 grain structure and alpha phase in wire-arc-directed energy deposition (DED-arc) Ti-6Al-4V by using a plasma deep melting treatment DED-arc Ti-6Al-4V component surface. After the introduction of plasma deep melting treatment, the DED arc Ti-6Al-4V component in the remelting region and no-remelting region had the same microstructure and consisted of coarse columnar (3 grains, basket-weave structures and acicular alpha '; however, the morphology and size of the microstructure obviously changed, such as the coarse columnar (3 grains broken by the remelting region, the refined basket-weave structures and acicular alpha ' obtained in the remelting region. The texture intensity of the alpha and (3 phases was also reduced under the action of the plasma deep melting treatment. The decrease in the average size of the prior-(3 grains strengthened the fine grains, and the alpha phase was refined to increase the dislocation density to strengthen the material. Therefore, compared with that of traditional samples, the tensile strengths of samples subjected to plasma deep melting in the building direction and deposition direction were increased by approximately 6.9 % and 8.3 %, respectively.

The development of efficient adsorbents for rapid strontium ion (Sr2+) sequestration holds crucial significance in addressing environmental remediation and radioactive waste management. Herein, we developed a series of zirconium-based metal-organic frameworks (Zr-MOFs: UiO-66-NH-Cys, -Ala, -His, -Phe, -Pro) functionalized with amino acids through post-synthetic modification (PSM), which improved Sr2+ adsorption performance. Notably, UiO-66-NH-Cys achieves a superior adsorption capacity (86.21 mg g- 1) under optimized conditions (pH 10.0, 298 K, initial concentration 300 mg L-1), outperforming pristine UiO-66-NH2 and other amino acidfunctionalized analogues. Mechanistic research indicates that Sr2+ binding primarily involves coordination with cysteine's thiol (-SH) and amine (-NH2) groups, complemented by ion exchange processes and electrostatic interaction. This work establishes amino acid-functionalized Zr-MOFs as precision-engineered adsorbents for selective Sr2+ removal, while providing a rational design strategy for addressing multifaceted aqueous contamination through targeted molecular engineering.

The atomic edge structure of graphene governs its unique electronic properties with applications in nanoscale electronics and optoelectronics. To fully realize its potential, it is critical to develop a precision etching process producing graphene edges along desired directions. Here, we present a novel approach utilizing scanning probe lithography (SPL) facilitated by a mechanochemical atomic attrition process. This technique enables the fabrication of nanopatterns in single-layer graphene from graphene edges, precisely along the crystallographic orientation of zigzag (ZZ) and armchair (AC) edges, without inducing mechanical damage to the surrounding area. Density functional theory (DFT) calculations revealed that the dissociation of C‒C bonds by the SPL probe is mediated by the formation of interfacial bridge bonds between the graphene edge and the reactive silica surface. This SPL-based mechanochemical etching method enables the construction of various nanodevice structures with specific edge orientations, which allows the exploitation of their electronic properties.

The corrosion mechanism of municipal solid waste incineration (MSWI) fly ash on magnesia-chromium refractories from the perspective of substance migration and transformation was investigated by using corrosion test at 1400 ℃. XRD, XRF, and SEM-EBSD characterization and thermodynamic software FactSage analysis were utilized. Although thermally stable compound MgCr2O4 can be formed in the refractories mitigating the corrosion, the SiO2 in the fly ash can convert MgCr2O4 to Mg2SiO4 (forsterite) and MgSiO3.The regeneration and transformation of MgCr2O4, as well as the low melting point and volume expansion properties of Mg2SiO4 and MgSiO3, are responsible for the loosening of the refractory structure and the migration of magnesium from the refractory into the ash. When the refractory was corroded by MSWI fly ash repeatedly, the migration of the corrosion products from the refractory to the ash was the key to aggravate the corrosion. Increasing CaO content can mitigate the corrosion and magnesium migration by alleviating the formation of Mg2SiO4 and MgSiO3.

In this study, Fe-based alloy coatings were prepared on 27SiMn substrates by laser cladding. To eliminate defects such as insufficient coating precision and excessive residual stress, the effects of ultrasonic high-frequency micro-forging (UH-FM) on coating microstructure and wear resistance were investigated. The experimental results show that the coating's surface roughness and residual stress are significantly reduced after UH-FM. The surface microstructure was broken and refined, and a gradient structure appeared. A part of the fcc phase was transformed into the bcc phase, which increased the resistance of dislocation movement, and the hardness of the coating increased. The width and depth of the abrasion marks and the wear weight loss of the treated coatings were reduced, and the compact oxide layer was distributed more uniformly, indicating that the UH-FM-treated coatings obtained better wear resistance.

Hydrogen peroxide photosynthesis suffers from insufficient catalytic activity due to the high energy barrier of hydrogen extraction from H 2 O. Herein, we report that mechanochemically synthesized keto-form anthraquinone covalent organic framework which is able to directly synthesize H 2 O 2 (4784 μmol h −1 g −1 at λ > 400 nm) from oxygen and alkaline water (pH = 13) in the absence of any sacrificial reagents. The strong alkalinity resulted in the formation of OH - (H 2 O) n clusters in water, which were adsorbed on keto moieties within the framework and then dissociated into O 2 and active hydrogen, because the energy barrier of hydrogen extraction was largely lowered. The produced hydrogen reacted with anthraquinone to generate anthrahydroquinone, which was subsequently oxidized by O 2 to produce H 2 O 2 . This study ultimately sheds light on the importance of hydrogen extraction from H 2 O for H 2 O 2 photosynthesis and demonstrates that H 2 O 2 synthesis is achievable under alkaline conditions.

Hydrogen peroxide (H2O2) photosynthesis from water and oxygen is a green and sustainable process with considerable promise as an alternative to the traditional anthraquinone method and an important method to realize decentralized production. Recently, several photocatalysts for H2O2 photosynthesis have been developed. Among these, polymer-based photocatalysts with flexible and tunable structural characteristics, broad optical responses and the potential for efficient H2O2 generation have attracted increasing attention. Herein, we critically review the state-of-the-art progress in polymer-based photocatalysts for H2O2 photosynthesis using only water and oxygen. Notably, enhancement strategies for H2O2 production over photocatalysts are emphasized, including carbon nitride, donor-acceptor conjugated frameworks and supramolecular polymers, and the relationship between the material structure and H2O2 production performance is also discussed. Finally, we discuss the challenges for further studies on H2O2 photosynthesis over polymer-based photocatalysts.

Sulfidated nano zero-valent iron (S-NZVI) as reductants coupled with organic carbon are promising in enhancing denitrification which is crucial for remediation of low C/N water body. Nevertheless, the dearth of research on the effectiveness of these materials in actual water remediation limits their application. Additionally, most of the studies utilizes industrial chemical-derived organic carbon, which exacerbates environmental and economic burdens. This study proposes employing pretreated stalks in-situ loaded S/Fe (SS-S/Fe) to remediate the low C/N slightly black-odorous water body. The pretreated stalk acts as carbon source replacing the industrial chemicals. The pretreatment process was carried out by using H2O2 and acetic acid to decrease the lignin content. The 2, 4-dichlorophenol was utilized as a target pollutant for optimization of materials. The sediment from the water body was remediated, the impact of SS-S/Fe on water body and microbial community structure were clarified. The lignin residues in the stalk were found to enhance the dispersity, O2 resistance, and reduction performance toward 2, 4-dichlorophenol of S/Fe. S/Fe facilitates 2, 4-dichlorophenol degradation via reduction and TP removal via forming Fe-P precipitation. SS plays a significant role in TN removal, assisting in enhancing the 2, 4-dichlorophenol and TP removal performance of S/Fe. Crucially, SS and S/Fe synergistically boost sediment microbial activity, conferring resistance to the subsequent pollution shock. The decisive role of SS in enhancing denitrification by cultivating Anaeromyxobacter, unclassified_f_Comamonadaceae, norank_f_norank_o_norank_c_Anaerolineae and Thiobacillus has been demonstrated. This study improves S-NZVI applicability in actual low C/N water bodies and provides new methods for utilizing stalk resources.

Converting conventional plastics into photodegradable plastics using photocatalysts as additives shows promise to develop degradable plastics sustainably and efficiently. However, inhibiting the degradation performance of the photocatalyst visually during usage of plastics remains challenging. We propose constructing a photocatalyst with a visualizable stable stage by using a complex of I-/I-2, a-cyclodextrin, and hydroxyethyl cellulose as the stable cage to modify TiO2. The stable cage possessing blue color inhibits the photocatalytic performance under illumination forming stable stage. After specific illumination periods, the stable cage changes to white and the photocatalytic performance starts. The photocatalyst is then added to low density polyethylene forming photodegradable plastics with a visualizable stable stage. The complex consumes photogenerated electrons and holes via I-5(-) /I-3(-) interconversion. During illumination, the evolution of the complex's band energy is crucial for controlling photocatalytic performance. This work paves the way to converting 99 % of plastics in the market into usable photodegradable plastics.

Polyvinyl alcohol (PVA) was used as a solid proton donor to improve the photocatalytic performance of graphitic carbon nitride (CN) for hydrogen peroxide (H2O2) production. The modified CN (CN/PVA) was prepared by mixing CN and PVA at room temperature. The H2O2 production efficiency of CN/PVA was 5.65 times higher than that of CN in pure water. Photocurrent measurement, electrochemical impedance spectroscopy (EIS), and photoluminescence (PL) analysis proved that PVA increased charge separation of CN. X-ray photoelectron spectroscopy (XPS), and Fourier-transform infrared (FTIR) analyses further suggested that PVA acted as the proton donor during H2O2 production by interacting with CN via hydrogen bonds. The combination of the charge separation enhancer and proton donor from PVA promoted the sequential two-step single-electron reduction of O-2 for H2O2 production. This study paves the way for the modification of g-C3N4 with hydroxyl-containing materials as solid proton donors for photocatalytic H2O2 production.

In this work, CrMnFeCoNi high-entropy alloy coating was successfully prepared on the surface of aluminum alloy by laser cladding. The relationship between the geometrical morphology of the coating cross section and laser process parameters was systematically studied. The influence of line energy and the number of remelting on the morphology of the coating cross section was mainly discussed, and the uniformity of coating elements distribution was regulated by multiple remelting. The coating cross-sectional dimensions, element distribution and hardness values were measured by stereomicroscope, energy-dispersive spectrometer and microhardness tester. The results show that the cladding height of CrMnFeCoNi high-entropy alloy coating increases first and then decreases with the increase of line energy, but the value changes slightly. The cladding width and cladding depth gradually increase with the increase of line energy and remelting times. When the coating is remelted 2 times, there is an incompletely melted island-like CrMnFeCoNi high-entropy alloy powder in the upper left corner of the coating. When remelting 3 times, there is no incompletely melted high-entropy alloy aggregate, and the uniformity of coating is better than that when remelting 2 times. The uniformity of coating composition is the best after 4 remelts, and the hardness of coating reaches 459.67HV0.2 when the line energy is 0.67 J/mm for 4 remelts.

Rapid removal of radioactive strontium from solutions is of great significance for ecosystem conservation. Herein, a new Cu-Zn-MOF namely, [NH 4 ] 3 [(Cu 3 Zn 2 (FDA) 6 (H 2 O) 8 Cl & sdot; 3H 2 O] ( Cu-Zn-MOF ; H 2 FDA = 2,5-furandicarboxylic acid) is designed for the efficient adsorption of radioactive Sr 2 + by ion exchange. The newly designed Cu-Zn-MOF possessed an anionic 2D -> 3D interpenetration framework based trinuclear centers which are charge -balanced by amino cations. Kinetic studies showed that Cu-Zn-MOF rapidly removed Sr 2 + (96.7 % in 4 h), and the kinetic data fitted well with the pseudo -second -order model. The adsorption isotherms were well described by Langmuir model and Cu-Zn-MOF exhibited high adsorption capacity (220.7 mg/g at 298 K), outperforming many state of the art adsorbents. More importantly, Cu-Zn-MOF exhibited intriguingly high selectivity for Sr 2 + in solutions containing coexisting ions with good reusability. The findings of this study can provide key and useful information for the adsorptive removal of Sr 2 + and other similar radioactive material with minimal processing and cost.

Nano zero-valent iron (NZVI) as reductants for pollutant removal is commonly studied. Nevertheless, its poor resistance to O-2 restricts its applicability, especially for polluted surface water bodies treatment. Here we proposed a method to enhance the O-2 resistance of NZVI by in-situ synthesis on a partially delignified stalk (SS/Fe). Compared to NZVI, SS/Fe did not ignite when exposed to air pulse during preparation, possessed a 56.1 % higher remaining 2, 4-dichlorophenol degradation performance after 28-day air exposure, and degraded 2, 4-dichlorophenol in the presence of O-2 with an equal efficiency to that under N-2. The characterization and DFT results indicated that the residual lignin in the stalk played a key role in controlling the structure and O-2 resistance of NZVI. Lignin in the stalk wrapped and anchored similar to 2 nm NZVI forming a spherical particle of size 49 +/- 21 nm which further aggregated forming a tertiary structure of size 790 +/- 280 nm. During air exposure, the phenolic hydroxy and methoxy groups in lignin changed the reaction equilibrium among Fe-0, Fe2+, and Fe3+ by reducing Fe3+ and acting as electron donors for Fe-0 and Fe2+. During 2, 4-dichlorophenol degradation, the lignin wrapping resulted in superior adsorption of 2, 4-dichlorophenol on SS/Fe and a lower electron transfer path between 2, 4-dichlorophenol and SS/Fe compared with that of interaction between O-2 and SS/Fe. This work provided a feasible method to facilitate the application of NZVI in treating polluted surface water bodies.

Photocatalytic H2O2 production is a promising strategy for decentralized applications, but to realize efficient H2O2 production in the ambient conditions and absence of organic sacrifice remains challengeable. Herein, anthraquinone functionalized covalent organic frameworks (TpAQ-COFs) were fabricated by beta-ketoenamines links of 2,6-diaminoanthraquinone (AQ) and 2, 4, 6-triformylphloroglucinol (Tp), and the structures and compositions were tuned by controlling the condensation time. The increase of time favors the assembly of TpAQCOFs into more ordered lamellar stacking structure, and induces the increase of enol-imine form. The critical role of anthraquinone moieties as the active sites for oxygen reduction was proved, that is, facilitating charge separation and enhancing the activity and selectivity of H2O2 production. Upon visible light irradiation, the TpAQ-COF synthesized after 12 h reaction has the highest content of anthraquinone moieties and the best performance for H2O2 production (420 mu mol h-1 g-1) in the absence of organic sacrificial agents. These findings bring insights to incorporate anthraquinone chemistry into photocatalysts at molecular levels for efficient H2O2 production.

In the rapidly evolving field of additive manufacturing (AM), the predictability of part properties is still challenging due to the inherent multiphysics complexity of the technology. This results in time-consuming and costly experimental guess-and-check approaches for manufacturing each individual design. Through synthesising advancements in the field, this review argues that numerical modelling is instrumental in mitigating these challenges by working in tandem with experimental studies. Unique hierarchical microstructures induced by extreme AM process conditions– including melt pool patterns, grains, cellular–dendritic substructures, and precipitates—affect the final part properties. Therefore, the development of microstructure-informed mechanical models becomes vital. Our review of numerical studies explores various modelling approaches that consider the microstructural features explicitly and offers insights into multiscale stress–strain analysis across diverse materials fabricated by powder bed fusion AM. The literature indicates a growing consensus on the key role of multiscale integrated process–structure–property–performance (PSPP) modelling in capturing the complexity of AM-produced materials. Current models, though increasingly sophisticated, still tend to relate only two elements of the PSPP chain while often focusing on a single scale. This emphasises the need for integrated PSPP approaches validated by a solid experimental base. The PSPP paradigm for AM, while promising as a concept, is still in its infantry, confronting multifaceted challenges that require in-depth, multidisciplinary expertise. These challenges range from accounting for multiphysics phenomena (e.g., advanced laser–material interaction) and their interplay (thermo-mechanical and microstructural evolution for simulating Type II residual stresses), accurately defined assumptions (e.g., flat molten surface during AM or purely epitaxial solidification), and correctly estimated boundary conditions for each element of the PSPP chain up to the need to balance the model’s complexity and detalisation in terms of both multiphysics and discretisation with efficient multitrack and multilayer simulations. Efforts in bridging these gaps would not only improve predictability but also expedite the development and certification of new AM materials.

Photocatalytic H2O2 production is a promising strategy to realize its decentralized application but limited by the low production efficiency in the absence of organic sacrifice. Herein, anthraquinone functionalized covalent organic frameworks (TpAQ-COFs) were fabricated by β-ketoenamines links of 2,6-diaminoanthraquinone (AQ) and 2, 4, 6-triformylphloroglucinol (Tp), and the structures and compositions were tuned by controlling the condensation time. The extending of condensation time favors to produce more ordered lamellar stacking structure and increase enol-imine contents. The critical role of anthraquinone moieties as the active sites for oxygen reduction was proved, that is, facilitating charge separation and enhancing the activity and selectivity of H2O2 production. Upon visible light irradiation, the TpAQ-COF after 12 h condensation has the highest content of anthraquinone moieties and the best performance for H2O2 production (420 μmol h-1g-1) from pure water. These findings bring insights to incorporate anthraquinone chemistry into photocatalysts at molecular levels for efficient H2O2 production.

Photocatalytically degradable plastics (PDP) are promising in mitigating plastic pollution due to their high degradability. Nevertheless, the unclear impact of environmental conditions on properties of debris for PDP and the knowledge gap in the mechanism from the perspective of photogenerated reactive species' function hinder PDP's application. Here, low-density polyethylene (LDPE) containing TiO2 (LDPE-TiO2) was selected as representative PDP. The photocatalytic degradation performance and mechanism of LDPE-TiO2 in water without NaCl, water with NaCl, and air were studied. Compared with water, the air resulted in a higher carbonyl index and higher molecular weight of debris from LDPE-TiO2 whether the irradiation time was the same (120 h) or the mass loss of LDPE-TiO2 was the same (68 +/- 2%). Chloride ions in water conditions resulted in C-Cl bond formation in the debris of LDPE-TiO2 suggesting generation of organochlorine substance. In the air the photogenerated electron (e(-)) contributed to LDPE-TiO2 film degradation, while in the water e(-) mainly underwent recombination with the photogenerated hole. In water with Cl-, HO center dot attacked LDPE via reaction with Cl- forming organochlorine substance. The effects of environmental conditions on the properties of debris and the functions of photogenerated reactive species for PDP degradation are reported for the first time in this study. The findings provide scientific support for the development of PDP technology. (C) 2021 Elsevier Ltd. All rights reserved.