ABSTRACT The coal spontaneous combustion process is complex, highly concealed, and difficult to prevent and control, often leading to environmental pollution and resource waste. To investigate the influence mechanism of active sites in coal on spontaneous combustion, molecular dynamics simulations were employed to quantitatively analyze the changes in global reactivity, local reactivity, and chemical bond parameters of the main functional groups and bridge bonds in coal macromolecular structures. The results show that the sulfur atoms in -SH and -S-S- have the highest radical attack indices (0.258 and 0.200, respectively) among the main oxidation sites in coal molecules. The global reactivity of characteristic functional groups in coal decreases in the following order: -COOH > -SH > -NH2 > -OH > -CH2-CH3, while the global reactivity of bridge bonds follows: -S-S- >-O- >-CH2-O- >-CH2-CH2-. The bond energy of bridge bonds in coal macromolecular structures is generally lower than that between functional groups and aromatic rings, making them prone to breakage during the low-temperature oxidation stage of coal. This leads to micro-degradation of coal, thereby enhancing its oxidation activity. The research findings will provide a key theoretical basis for studying coal spontaneous combustion and improving prevention technologies.

Density functional theory (DFT) calculations and an atomistic thermodynamic approach were employed to identify the active nickel sites and determine the chemical nature of the hydrogen species in the nickel phosphosulfide overlayer formed on the (0001) and (101̄0) surfaces of the Ni2P hydrotreating catalyst. Our results showed that Ni(1) sites are less resistant to sulfur than Ni(2) sites, in agreement with experimental observations. Under HDS conditions, the fully sulfided (0001) surface of Ni2P was found to be structurally similar to the (111) surface of the low-activity sulfide Ni3S2, where closely coordinated Ni atoms are prone to sulfidation. Non-hydrogenated surfaces were always the most stable, suggesting that NiH and SH groups are unlikely to form on these surfaces. In contrast, the most stable (101̄0) surface was identified as a hydrogenated surface with coordinatively unsaturated Ni(2) atoms surrounded by SH groups. Depending on the electronegativity of their ligands (S or Ni), the hydrogen species exhibit either protonic (Hδ+) or hydridic (Hδ-) character. Our results suggest that protons within SH groups are the most likely reactive hydrogen species on the nickel phosphosulfide overlayer under reaction conditions, providing atomic-level insight into the origins of HYD activity in Ni2P catalysts.

A Pt-Co catalyst supported on ZIF-8-derived porous carbon (Pt-Co/Z-HP) with strong metal-support interaction (SMSI) was developed for efficient room-temperature formaldehyde (HCHO) oxidation. The catalyst exhibited highly dispersed Pt nanoparticles, abundant surface hydroxyl groups, and a defect-rich nitrogen-doped carbon matrix. These features promote Pt stabilization, oxygen activation, and intermediate conversion, achieving nearly 100% HCHO removal and CO2 selectivity under ambient conditions. Density functional theory (DFT) calculations further revealed that plasma-induced -OH species regulate the surface coverage of active hydroxyls, maintaining a balance between O2 activation and HCHO adsorption. Moreover, comparative models of isolated Co and Pt clusters (Conp-Ptnp-NC) and Pt-Co alloy clusters (CoPtnp-NC) demonstrate that the alloy structure achieves lower reaction barriers for both O2 dissociation and HCHO oxidation via synergistic dual-site cooperation. These findings highlight that appropriate -OH coverage and Pt-Co electronic synergy are critical for enhancing catalytic performance. This work provides a low-energy approach for designing advanced volatile organic compounds (VOCs) oxidation catalysts via tailored SMSI.

With the continuous development of society, the energy issue has emerged as a critical problem that requires resolution. This study describes the in situ loading of ZIS nanosheets onto the surface of a two-dimensional CMS square platform using solvothermal and low-temperature oil bath methods to create a 2D/2D CMS/ZIS composite photocatalyst for hydrogen production via photocatalysis. Without any noble metal co-catalyst, the hydrogen production attained by CMS/ZIS-10 under visible light is around 2642 μmol g-1 h-1, which is about double that of ZIS. The research results show that the construction of the heterojunction increases the material's light absorption spectrum, improves the self-assembly agglomeration of ZIS, exposes more active sites, and effectively augments the efficacy of separation and migration of photogenerated electrons, hence improving the efficiency of the photocatalytic process. The density functional theory (DFT) calculation verifies that the charge transfer pathway of the synthesized composite material corresponds to the F-type heterojunction charge transfer pathway. When an internal electric field is present, the photogenerated electrons of ZIS transfer to the CMS conduction band and maintain strong redox ability, thereby improving the photocatalytic performance.

Acetylation of lysine residues in the tail domain of histone H3 is well characterised, but lysine residues in the histone globular domain are also acetylated. Histone modifications in the globular domain have regulatory potential because of their impact on nucleosome stability but remain poorly characterised. In this study, we report the genome-wide distribution of acetylated H3 lysine 115 (H3K115ac), a residue on the lateral surface at the nucleosome dyad, using chromatin immunoprecipitation. In mouse embryonic stem cells, we find that detectable H3K115ac is enriched at the transcription start site of active CpG island promoters, but also at polycomb-repressed promoters prior to their subsequent activation during differentiation. By contrast, at enhancers, H3K115ac enrichment is dynamic, changing in line with gene activation and chromatin accessibility during differentiation. Most strikingly, we show that H3K115ac is detected as enriched on 'fragile' nucleosomes within nucleosome-depleted regions at promoters and active enhancers, where it coincides with transcription factor binding, and at CTCF-bound sites. These unique features suggest that H3K115ac correlates with, and could contribute to, nucleosome destabilisation and that it might be a valuable marker for identifying functionally important regulatory elements in mammalian genomes.

The paper presents the results of developing paint and varnish coatings for protecting metal bridge structures, featuring high durability under operating conditions. The focus is on preparing metal surfaces for painting, specifically developing a formulation for a pre-treatment composition prior to paint and varnish application. The composition is a solution based on mixed solvents, one of which is an ester and the other an aromatic hydrocarbon, containing nanomaterials. The specific solvents used in the composition, as well as the types and amounts of nanomaterials, depend on the type of film-forming agent in the applied paint and varnish. The conducted studies on a specific example of a composition formulation, including a solution based on mixed solvents (butyl acetate (52-55 wt.%) and toluene (45-48 wt.%), containing a concentrate with carbon nanotubes and silicon dioxide, in an amount of 0.01-0.2 wt.%, including 10 wt.% single-wall carbon nanotubes and silicon dioxide nanoparticles and 90 wt.% mixture of triethylene glycol dimethacrylate and alkylammonium salt of high-molecular copolymers showed that acrylic paint and varnish coatings acquire increased physical and mechanical properties (adhesive strength, abrasion resistance, resistance to deformation effects, etc.). At the same time, there is an increase in the dielectric constant of the coating (from 16.45 to 18.39), which characterizes its increased conductivity, as well as a decrease in the dielectric loss tangent (from 0.017 to 0.008), which indicates the production of antistatic coatings. The chemical resistance of the coatings increases, which characterizes their resistance to aggressive environments, expressed in better preservation of properties according to the criteria: change in gloss (hue), whitening, blistering, peeling, wrinkling. When considering the formation of interaction on the metal surface during its contact with the coating during surface treatment with nanomaterials, the following mechanisms of action of nanomaterials with a metal surface were revealed, which are consistent with the provisions of the electrical theory of adhesion and the theory of the physical chemistry of polymers: interaction of nanomaterials with surface atoms of the metal with the formation of electrovalent interaction by the donor-acceptor mechanism; Chemical interaction (chemisorption) of the active sites on the surface of carbon nanotubes with the metal surface layer. Industrial testing of the resulting solution yielded a positive result: after 28 months of operation, the coating obtained by surface treatment with the nanomaterial composition, compared to the untreated coating, performs its functions and exhibits superior decorative and protective properties. The technical and economic efficiency of the developed approach is ensured by improved adhesive-cohesive interaction of paint and varnish coatings, which creates conditions for extending their service life and periods between repairs; and by reducing resource and energy costs without compromising coating quality due to the use of a small amount of binary nanomaterials in the developed composition.

Methane, a highly hazardous gas mixture when exposed to open flames, is commonly encountered in coal mines. Its primary component is CH4, making the detection of its concentration, especially under diverse environmental conditions, highly significant. In this study, La0.7Gd0.3Fe0.9Co0.1O3 nanomaterials were prepared using an ultrasound-assisted hydrothermal method. Through dual-site synergistic regulation involving Gd doping at the A-site and Co doping at the B-site, rapid detection of CH4 at low temperatures was achieved. At 150 ∘C, the sensor demonstrated a significantly enhanced response to 100 ppm CH4, with a sensitivity of 10.22. This value represents an approximately tenfold improvement over that achieved with pure LaFeO3. In addition, the sensor responded rapidly to the gas exposure within 6.3 s and recovered within 5.4 s, respectively, at the same gas concentration. Such swift recovery capabilities enable reliable detection across multiple environmental conditions. Moreover, the sensor not only shows excellent repeatability but also maintains a high response value of 9 even under highly humid conditions (95% RH). The performance enhancement is attributed mainly to lattice distortion induced by A-site doping and the increased active sites provided by B-site doping. The development of this sensor lays a foundation for future CH4 detection and industrial safety applications.

The well-known medicinal plant Erigeron breviscapus has long been used to treat cerebral embolism, cerebral thrombosis, and cerebral hemorrhage. Response surface methodology (RSM) was applied to optimize the ultrasonic-assisted extraction process of total flavonoids from Erigeron breviscapus (EBTF) using aqueous two-phase system. The flavonoids fromE. breviscapuswere qualitatively identified using UPLC-Q-TOF-MS/MS. The capacity of EBTF to scavenge ·OH was used to assess its antioxidant activity. To determine the active sites in the primary bioactive components that scavenge ·OH, density functional theory (DFT) calculations were conducted. Total flavonoid content (TFC) from E. breviscapus was 48.53mg/g under ideal conditions with PEG2000 mass fraction of 16%, (NH4)2SO4 mass fraction of 14%, ultrasound time of 41min, and liquid-solid ratio of 35 mL/g. 28 flavonoids have been tentatively identified in E. breviscapus via ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS/MS). Furthermore, EBTF demonstrated moderate hydroxyl radical scavenging capacity, with scavenging rate of 60.68% at 3.9mg/mL. The 6-OH site of scutellarin was the core active site for scavenging hydroxyl radicals. The findings provide both theoretical and experimental support for the in-depth development of EBTF as a natural antioxidant.

High-entropy alloys (HEAs) exhibit excellent catalytic activity owing to their unique structure and chemical properties. The construction of hierarchical porous HEA catalysts via laser powder bed fusion (LPBF, a typical 3D printing technology) and dealloying techniques opens new avenues for boosting catalytic performance. This study reports the fabrication of a hierarchical porous FeCoNiCuAl HEA catalyst through a two-step strategy: LPBF and subsequent dealloying. The macroscopic triply periodic minimal surface (TPMS) structure of the HEA catalyst was constructed through LPBF, followed by dealloying to create a nanoporous structure on the catalyst surface. The hierarchical porous FeCoNiCuAl HEA catalyst exhibited a catalytic activity 4.33 times higher than that of the pristine, non-porous FeCoNiCuAl HEA (HEA-0). Furthermore, the catalyst maintained nearly 100% degradation efficiency for Acid Red G (ARG) after 20 consecutive catalytic cycles, demonstrating exceptional stability. This stepwise strategy for constructing hierarchical porous structures not only accelerates mass transfer via the macroporous framework but also significantly increases the density of accessible active sites through the nanoporous surface, thereby synergistically enhancing the catalytic activity of HEAs. This work provides a novel and scalable approach for developing high-performance porous HEA catalysts for wastewater treatment.

The development of low-temperature, high-efficiency catalysts for the catalytic elimination of chlorinated volatile organic compounds (CVOCs) remains a significant challenge. Investigating the influence mechanism of catalyst physicochemical properties on chlorobenzene oxidation performance and degradation pathways is particularly important. CuO/WO3 catalysts were developed using a hydrothermal method in this work. The effects of simultaneous or separate addition of ammonium sulphate and ammonium persulphate on the catalytic performance of the CuO/WO3 series catalysts were investigated. The results showed that the introduction of ammonium sulphate alone can facilitate the formation of CuWO4, thereby increasing the chemisorbed oxygen concentration of the CuO/WO3, and making the overall structure of the catalyst looser and increasing the active sites on the catalyst surface. As the optimal catalyst, CuO/WO3-2 exhibited 55.9% of chlorobenzene conversion and 32.9% of CO2 selectivity at 500 °C. Interestingly, although the surface acidity in this work seemed to be one of the reasons for promoting the chlorobenzene oxidation, it could be clearly found that the strong solid acidity of WO3 was actually a key factor in inhibiting the chlorobenzene oxidation. Finally, based on in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) analysis, the primary mechanism for chlorobenzene oxidation on CuO/WO3 catalysts proceeds through a sequential conversion: chlorobenzene was first transformed into phenolic intermediates, followed by quinone compounds, maleates, aldehydes, bidentate carbonates, and ultimately carbonate species.

Among viable approaches to address the current energy crisis, photocatalytic water splitting to produce hydrogen (H2) stands out as a promising strategy for converting solar energy into storable chemical energy. In this study, FeCoNiCuPt high-entropy alloy particles (HEA) are loaded onto protonated g-C3N4 nanosheets (HCN NSs) to construct HEA/HCN composites through an electrostatic self-assembly method. Protonation treatment enriches the surface of g-C3N4 nanosheets with abundant active sites and enhances their interfacial charge separation capability. The optimal HEA/HCN composite exhibits a remarkable hydrogen evolution rate of 1672 µmol·h-1·g-1, representing a 98.35-fold enhancement compared to pristine HCN. The apparent quantum efficiency of HEA/HCN composite reaches 3.23% at λ = 370nm. Experimental characterizations reveal that the 2D ultrathin protonated g-C3N4 nanosheets possess a substantial specific surface area and shortened charge transfer distance, facilitating rapid migration of photoexcited electrons. The incorporation of HEA cocatalysts not only introduces additional active sites but also establishes Schottky junctions at the HEA/HCN interface. The synergistic effect effectively accelerates electron transport and suppresses the recombination of photogenerated carriers, thereby significantly enhancing the photocatalytic H2 production performance. This work provides new insights into the future application of high-entropy alloys as novel cocatalysts in photocatalysis.

The compositional heterogeneity of post-consumer plastic waste, exemplified by prevalent polyethylene (PE)/polypropylene (PP) mixtures (>50% of the plastic market), severely complicates recycling. Kinetic disparities between PE and PP during chemical recycling create significant conversion gradients, limiting valued product yield and process viability. Here, leveraging strong interfacial coupling between ruthenium oxides and rutile TiO2, we construct highly active, epitaxial RuOx sites enabling efficient one-pot co-conversion of PE/PP mixtures with a high liquid yield of 95.02%, while maintaining a low 0.62% gas yield. Compared to conventional Ru nanoparticles, the epitaxial RuOx structure provides additional dehydrogenation sites for PP activation, which promotes carbon-metal back-donation to weaken C-C bonds, thus exhibiting comparable activation capabilities toward both 3C-2C bond in PP and 2C-2C bond in PE. This unique epitaxial catalyst enables highly efficient co-hydrogenolysis of mixed polyolefins, establishing a practical approach for their upcycling.

Sulfur-doped graphene (SG) has attracted considerable interest for energy conversion and storage applications. However, the relevant catalytic mechanisms remain obscure due to ongoing contentious debates regarding the location of dopant atoms. While theoretical studies often assume sulfur dopants preferentially reside at edge sites, experimental evidence consistently shows their homogeneous distribution throughout the carbon lattice. Here, we first demonstrated the thermal and dynamical instabilities of previously proposed models of S-bearing defects in the basal plane of SG, which were used to explain experimentally observed enhanced lithium adsorption and magnetism. We then presented new stable defect configurations in the graphene lattice that incorporate both sulfur dopants and inevitable oxygen-bearing functional groups, thereby explaining those experimental observations. These in-plane defect models provide an internally consistent explanation for the active sites and catalytic mechanisms of oxygen, nitrogen, and sulfur reduction reactions, and suggest that the catalytic performance of SG cannot be rationalized solely by edge-located sulfur dopants. In particular, several of the newly identified in-plane defects exhibit calculated activities comparable to, or in some cases exceeding, those of representative edge configurations. Our findings highlight a previously underappreciated role of basal-plane defects in sulfur-doped carbonaceous materials, encompassing both metal-free catalysts and graphene-based single-atom systems.

Metal sulfide (MS) photocatalysts hold unique features of narrow-bandgap range, high light absorption coefficient, and suitable band structures, offering significant potential for efficient visible-light photocatalytic hydrogen evolution (PHE) via water splitting. However, the low electronic dimensionality of the traditional MS photocatalyst generally decreases the transfer and migration efficiency of the photogenerated charge carriers. In addition, severe intrinsic photocorrosion issue also severely reduces the photostability, hindering the practical application of PHE at scale. In this regard, the advanced design concept of MS photocatalysts, focusing on the high electronic dimensionality construction and efficient photocorrosion inhibition, is of great importance. This review firstly introduces the basic mechanisms of PHE, followed by an in-depth discussion of the fundamental distinction between structural dimensionality and electronic dimensionality, highlighting the superiority of 3D electronic connectivity in enabling isotropic charge migration and shallow defect states. Afterward, the MS photocatalysts with 3D electronic dimensionality and solutions to photocorrosion are systematically summarized, with a special emphasis on the emerging paradigm of advanced "controllable-photocorrosion," which strategically utilizes the corrosion process to create active sites rather than merely suppressing it. Finally, the current unsolved challenges of MS photocatalysts are comprehensively discussed.

Induction heating offers a promising route to intensify CO2 desorption. Conventionally, ferromagnetic powders are dispersed in the solvent as susceptor materials. In this study, 430 stainless steel mesh coated with a thin layer of copper and directly immersed in the solvent was used to replace such powders. Induction tests show that the coated mesh reaches the target temperature even at low frequency and low excitation current. Desorption experiments were subsequently conducted for various CO2-rich ChCl-MEA formulations. Under electromagnetic induction, the MCu3 system delivered the best performance: a desorption efficiency of 93.54%, a desorption rate of 0.3302 × 10-3 g CO2·g-1 absorbent·s-1, and an energy requirement of only 2.33 GJ·t-1 CO2. Compared with the uncatalyzed system under conventional conduction heating, this exceptionally high desorption rate benefits from the stainless-steel mesh's highly efficient magnetothermal effect, the proton-transfer active sites that the surface copper layer offers for chemical catalysis, and-thanks to copper's high thermal conductivity-the noticeably more uniform heat transfer achieved under induction heating. This magnetothermal-catalytic strategy opens a scalable, low-energy pathway for absorbent regeneration in industrial CO2 capture processes.

The construction of heterogeneous catalysts for the solvent-free cycloaddition of CO2 with epoxides is critical for atom-economical synthesis of cyclic carbonates yet remains a formidable challenge. In this work, a WO3-MoO3 heterostructure is constructed for the solvent-free coupling of CO2 with styrene oxide (SO). This design can induce collaborative effects via interfacial electron transfer between WO3 and MoO3, thereby facilitating charge redistribution and creating unique electronic configurations. As a result, the cycloaddition kinetics are significantly enhanced, as reflected by a markedly lower apparent activation energy (17.6 kJ mol-1) than those of pristine WO3 (30.1 kJ mol-1) and MoO3 (30.8 kJ mol-1). The WO3-MoO3 catalyst achieves a high styrene carbonate (SC) yield of 93.7%, with a normalized reaction rate of 2.9 × 10-2 mol m-2 h-1 under solvent-free conditions, and demonstrates good cycling stability. This study highlights the effectiveness of heterostructure engineering in tailoring active sites and electronic properties, offering a promising strategy for developing high-performance CO2 fixation catalysts.

Mechanochemical activation drives non-chemisorbed oxygen-dependent Hg0 oxidation across wide temperature.

Fe-Cu bimetal/N-doped carbon nanotubes with oxygen vacancies and multivalent redox cycling for ultrasensitive electrochemical detection of benomyl in fruit samples.

NOx decomposition through seaweed biocarbon as biosourced catalyst: Experimental and density functional theory approaches.

Electrochemically reconstructed defect-rich Cu/Co nanoreactor for ultrafast ammonia electrosynthesis from low-concentration nitrate.