Efficient photoelectrocatalytic degradation of pollutants over hydrophobic carbon felt loaded with Fe-doped porous carbon nitride via direct activation of molecular oxygen.

Developing a photoelectric cathode capable of efficiently activating molecular oxygen to degrade pollutants is a coveted yet challenging goal. In pursuit of this, we synthesize a Fe doped porous carbon nitride catalyst (Fe-CN) using an ionothermal strategy and subsequently loaded it on the hydrophobic carbon felt (CF) to fabricate the Fe-CN/CF photoelectric cathode. This cathode benefits from the synergistic effects between the porous CN support and the highly dispersed Fe species, which enhance O2 absorption and activation. Additionally, the hydrophobic CF serves as a gas diffusion layer, accelerating O2 mass transfer. These features enable the Fe-CN/CF cathode to demonstrate notable photoelectrocatalytic (PEC) degradation efficiency. Specifically, under optimal conditions (cathodic bias of -0.3 VAg/AgCl, pH 7, and a catalyst loading of 3 mg/cm2), the system achieves a 76.4% removal rate of tetracycline (TC) within 60 min. The general application potential of this system is further underscored by its ability to remove approximately 98% of 4-chlorophenol (4-CP) and phenol under identical conditions. Subsequent investigations into the active species and degradation pathways reveal that 1O2 and h+ play dominant role during the PEC degradation process, leading to gradually breakdown of TC into less toxicity, smaller molecular intermediates. This work presents a straightforward yet effective strategy for constructing efficient PEC systems that leverage molecular oxygen activation to degrade pollutants.

Influence of an External Electric Field on Electronic and Optical Properties of a g-C3N4/TiO2 Heterostructure: A First-Principles Perspective.

In this study, calculations based on density functional theory (DFT) were utilized to examine how electrostatic fields affect the electrical and optical characteristics of g-C3N4/TiO2 heterostructures. The binding energy, density of states, difference in charge density, and optical absorption spectra of the heterostructure were calculated and analyzed to reveal the mechanism of the influence of the external electric field (EF) on the properties of the heterostructure. The results show that the binding energy of the heterogeneous structure is reduced due to the imposed electric field in X- and Y-directions, and the optical absorption spectrum is slightly enhanced, but the BG and charge transfer number are basically unchanged. On the contrary, applying the electric field in the Z-direction increases the binding energy of the heterogeneous structure, decreases the BG, increases the number of charge transfers, and red shifts the optical absorption spectrum, which improves the photocatalytic ability of the g-C3N4/TiO2 heterostructure.

Efficient visible-light-driven degradation of tetracycline by a 2D/2D rGO-Bi2WO6 heterostructure.

Constructing heterostructures has been a simple yet effective strategy for improving the photocatalytic performance of individual semiconductor photocatalysts. However, the poor quality of the contacted interface coupled with the narrow and overlapping light absorption scope between heterocomponents limits potential improvement. Herein, a 2D/2D rGO-Bi2WO6 heterostructure with face-to-face compact contact interface and UV to NIR light absorption ability was synthesized to overcome the aforementioned limitations. The as-prepared 2 wt%-rGO-Bi2WO6 with a high contact interface quality exhibits the highest kinetic rate of (5.53 ± 0.75) × 10-2 L mg-1 min-1 toward tetracycline (TC) degradation, which is 2.4 times higher than that of pristine Bi2WO6 and 2.1 times higher than that of the 2 wt%-rGO-Bi2WO6 composite with a poor interface quality. Moreover, approximately 30% of TC can be mineralized with a 2 wt%-rGO-Bi2WO6 presented system after 120 min. The subsequent Escherichia coli culture and liquid chromatography-mass spectrometry were employed to detect the biotoxicity variation of degradation intermediates and the possible transformation pathways of TC, respectively. Finally, the reactive species trapping results indicate that photogenerated holes and superoxide radical anions play dominant roles during the TC degradation process. This work provides a facile and effective method to fabricate an efficient heterojunction photocatalyst for pollutant degradation.

Self-Assembled Sandwich-like MXene-Derived Composites as Highly Efficient and Sustainable Catalysts for Wastewater Treatment.

Photocatalysts play an increasingly important role in environmental remediation polluted by industrial wastewater. However, the preparation of adsorbents and catalysts with high activity by simple and easy methods is still a great challenge. Here, sandwich-like composite catalyst Cu2O/TiO2/Ti3C2 was prepared by an easily available solvent reduction measure for the highly efficient catalytic nitro compounds. In particular, sandwich-like composite catalyst Cu2O/TiO2/Ti3C2 exhibits excellent catalysis for 2-nitroaniline (2-NA) and 4-nitrophenol (4-NP), and its pseudo-first-order reaction rate constants (k) are 0.163 and 0.114 min-1, respectively. Interestingly, even after eight consecutive cycles of catalytic experiments, the conversion rates of catalytic 2-NA and 4-NP are still greater than 95 and 92%, respectively, demonstrating that the obtained catalyst has excellent catalytic capability and a high reutilization rate. The excellent catalytic performances of Cu2O/TiO2/Ti3C2 can be attributed to the fact that Ti3C2 provides a greater reaction site for the formation of Cu2O and reduces the aggregation during the formation of Cu2O by in situ synthesis. Therefore, ternary composite catalyst Cu2O/TiO2/Ti3C2 prepared by solvent reduction not only supplies a technical method for the catalytic reaction of MXene-based material but also lays the foundation for the development of new photocatalysts.

The porous structure effects of skeleton builders in sustainable sludge dewatering process.

Dewatering from sludge is an important sustainable issue in recent years, in this work, we found the unique behavior: Skeleton builder additions can improve the dewatering performance greatly, which related to the different pore structure of skeleton builder. As compared to the coal ash, sawdust and rice husk char are easier to construct porous channels in the sludge body, which is responsible for the discharge of water. the dewatering efficiency can increased from approximately 30%-65% by pipe network effect and interlayer channel effect, a sufficient amount of skeleton builders establish a complete pipe drainage network in the sludge body, allowing the water to be discharged fluently. Moreover, the skeleton builders can cause the sludge body to form a layered structure. Under the combined action of pipe network effect and interlayer channel effect, the deep-dewatering effect increased largely by the addition of skeleton builders.

Synthesis and Near Infrared Luminescence Properties of a Series of Lanthanide Complexes with POSS Modified Ligands.

A polyhedral oligomeric silsesquioxanes (POSS) modified 8-hydroxyquinoline derivative (denoted as Q-POSS) was synthesized and used as a ligand to coordinate with lanthanide ions to obtain a series of lanthanide complexes Ln(Q-POSS)3 (Ln = Er3+, Yb3+, Nd3+). The as-prepared lanthanide complexes have been characterized by FT-IR, UV⁻Vis, and elemental analysis. All these complexes showed the characteristic near-infrared (NIR) luminescence originated from the corresponding lanthanide ions under excitation. Compared with the unmodified counterparts LnQ3 (HQ = 8-hydroxyquinoline), the Ln(Q-POSS)3 complexes showed obviously increased emission intensity, which was ascribed mainly to the steric-hindrance effects of the POSS moiety in the ligands. It is believed that the POSS group could suppress undesired excimer formation and intermolecular aggregation, thus decreasing the concentration quenching effect of the corresponding lanthanide complexes.

Selective and Efficient Removal of Fluoride from Water: In Situ Engineered Amyloid Fibril/ZrO2 Hybrid Membranes.

We report a new strategy for efficient removal of F- from contaminated water streams, and it relies on carbon hybrid membranes made of amyloid fibril/ZrO2 nanoparticles (<10 nm). These membranes exhibit superior selectivity for F- against various competitive ions, with a distribution coefficient (Kd ) as high as 6820 mL g-1 , exceeding commercial ion-exchange resins (IRA-900) by 180 times and outdoing the performance of most commercial carbon-activated aluminum membranes. At both low and high (ca. 200 mg L-1 ) F- concentrations, the membrane efficiency exceeds 99.5 % removal. For real untreated municipal tap water (ca. 2.8 mg L-1 ) under continuous operating mode, data indicates that about 1750 kg water m-2 membrane can be treated while maintaining drinking water quality, and the saturated membranes can be regenerated and reused several times without decrease in performance. This technology is promising for mitigating the problem of fluoride water contamination worldwide.

A simple and convenient sticky/blunt-end ligation method for fusion gene construction.

Here we present a simple and convenient sticky/blunt-end ligation method for fusion gene construction. The fusion gene is constructed by seamless ligation of 5'-end phosphorylated blunt ends instead of by overlap extension PCR (OE-PCR). Therefore, the challenge of amplifying large DNA fragments (e.g., the large bifunctional enzyme gene constructed by fusion of two monofunctional enzyme genes) by PCR can be avoided. In addition, synthesis of the inner primers for OE-PCR is not necessary, indicating that this method should be especially convenient for construction of fusion genes with various combinations of multiple fragments (e.g., chimeric gene libraries, fusion gene libraries). As a modification of the commonly used fusion gene construction technique, this method may find a wide range of applications in bioscience and biotechnology.

Unique lead adsorption behavior of activated hydroxyl group in two-dimensional titanium carbide.

The functional groups and site interactions on the surfaces of two-dimensional (2D) layered titanium carbide can be tailored to attain some extraordinary physical properties. Herein a 2D alk-MXene (Ti3C2(OH/ONa)(x)F(2-x)) material, prepared by chemical exfoliation followed by alkalization intercalation, exhibits preferential Pb(II) sorption behavior when competing cations (Ca(II)/Mg(II)) coexisted at high levels. Kinetic tests show that the sorption equilibrium is achieved in as short a time as 120 s. Attractively, the alk-MXene presents efficient Pb(II) uptake performance with the applied sorption capacities of 4500 kg water per alk-MXene, and the effluent Pb(II) contents are below the drinking water standard recommended by the World Health Organization (10 µg/L). Experimental and computational studies suggest that the sorption behavior is related to the hydroxyl groups in activated Ti sites, where Pb(II) ion exchange is facilitated by the formation of a hexagonal potential trap.

Hydrogen sulfide attenuates hypoxia-induced neurotoxicity through inhibiting microglial activation.

Endogenously produced hydrogen sulfide (H2S) may have multiple functions in the brain including potent anti-inflammatory effects. Activated microglia can secrete various pro-inflammatory cytokines and neurotoxic mediators, which may contribute to hypoxic injuries in the developing brain. The aim of this study is to investigate the potential role of H2S in altering hypoxia-induced neurotoxicity via its anti-inflammatory actions as examined in vitro and in vivo models. Using the BV-2 microglial cell line, we found that sodium hydrosulfide (NaHS), a H2S donor, significantly inhibited hypoxia-induced microglial activation and suppressed subsequent pro-inflammatory factor release. In addition, treating murine primary cortical neurons with conditioned medium (CM) from hypoxia-stimulated microglia induced neuronal apoptosis, an effect that was reversed by CM treated with NaHS. Further, NaHS inhibited phosphorylation of the p65 subunit of NF-κB, phosphorylation of ERK and p38 but not JNK MAPK in these hypoxia-induced microglia. When administered in vivo to neonatal mice subjected to hypoxia, NaHS was found to attenuate neuron death, an effect that was associated with suppressed microglial activation, pro-inflammatory cytokines and NO levels. Taken together, H2S exerts neuroprotection against hypoxia-induced neurotoxicity through its anti-inflammatory effect in microglia. This effect appears to be attributable to inhibition of iNOS, NF-κB, ERK and p38 MAPK signaling pathways. Our results suggest a potential therapeutic application of H2S releasing drugs in hypoxic brain damage treatment.

Accelerated OH(-) transport in activated carbon air cathode by modification of quaternary ammonium for microbial fuel cells.

Activated carbon (AC) is a promising catalyst for the air cathode of microbial fuel cells (MFCs) because of its high performance and low cost. To increase the performance of AC air cathodes, the acceleration of OH(-) transport is one of the most important methods, but it has not been widely investigated. Here we added quaternary ammonium to ACs by in situ anchoring of a quaternary ammonium/epoxide-reacting compound (QAE) or ex situ mixing with anion exchange resins in order to modify ACs from not only the external surface but also inside the pores. In 50 mM phosphate buffer solution (PBS), the in situ anchoring of QAE was a more effective way to increase the power. The highest power density of 2781 ± 36 mW/m(2), which is 10% higher than that of the control, was obtained using QAE-anchored AC cathodes. When the medium was switched to an unbuffered NaCl solution, the increase in maximum power density (885 ± 25 mW/m(2)) was in accordance with the anion exchange capacity (0.219 mmol/g). The highest power density of the anion exchange resin-mixed air cathode was 51% higher than that of the control, indicating that anion exchange is urgently needed in real wastewaters. Excess anchoring of QAE blocked both the mesopores and micropores, causing the power output to be inhibited.

Supramolecular assembly and nanostructures of a series of luminol derivatives with aromatic/alkyl substituted groups in Langmuir-Blodgett films.

A series of functional luminol derivatives with aromatic and alkyl substituted groups has been designed and synthesized from the reaction of the corresponding chloride precursors with luminol. These compounds can be spread on water surface to form stable Langmuir films at the air-water interface. It has been found that UV and IR spectra confirmed the characteristic aromatic segment, imide group, and aromatic/alkyl substituted groups. In addition, for the interfacial assembly process of compounds with alkyl substituted groups, there are obvious spectral changes for the alkyl chains. AFM results indicated that various different aggregated domains may be fabricated in the transferred LB films. For all cases, the substituted groups in molecular structures have an important effect in regulating the aggregation mode and spectral changes in organized molecular films. The present results showed that the modified luminol derivatives may have potential application in functional material fields such as ECL sensor, which may give some insight to study the relationship between the molecular structures and supramolecular aggregation of amphiphiles in organized molecular films.

Removal of ammonia from landfill leachate by struvite precipitation with the use of low-cost phosphate and magnesium sources.

This paper presents a study concerning ammonia removal from landfill leachate by struvite precipitation with the use of waste phosphoric acid as the phosphate source. The results indicated that the Al(3+) ions present in the waste phosphoric acid significantly affected the struvite precipitation, and a removal ratio of ammonia close to that of pure phosphate salts could be achieved. Nevertheless, large amounts of NaOH were necessary to neutralize the H(+) present in the waste phosphoric acid. To overcome this problem, a low-cost magnesium source was proposed to be used as well as an alkali reagent in the struvite precipitation. The ammonia removal ratios were found to be 83%, with a remaining phosphate of 56 mg/L, by dosing the low-cost MgO in the Mg:N:P molar ratio of 3:1:1. An economic analysis showed that using waste phosphoric acid plus the low-cost MgO could save chemical costs by 68% compared with the use of pure chemicals. Post-treatment employment of a biological anaerobic filter process demonstrated that the high concentration of Mg(2+) remaining in the effluent of the struvite precipitation has no inhibitory effect on the performance of the biological treatment.

Organic cocatalysts improved Fenton and Fenton-like processes for water pollution control: A review.

In recent times, organic compounds have been extensively utilized to mitigate the limitations associated with Fe(Ⅲ) reduction and the narrow pH range in Fenton and Fenton-like processes, which have garnered considerable attention in relevant studies. This review presents the latest advancements in the comprehensive analysis and applications of organic agents as assistant/cocatalysts during Fenton/Fenton-like reactions for water pollution control. The primary focus includes the following: Firstly, the mechanism of organic co-catalytic reactions is introduced, encompassing both complexation and reduction aspects. Secondly, these organic compounds are classified into distinct categories based on their functional group structures and applications, namely polycarboxylates, aminopolycarboxylic acids, quinones, phenolic acids, humic substances, and sulfhydryl compounds, and their co-catalytic functions and mechanisms of each category are discussed in meticulous detail. Thirdly, a comprehensive comparison is conducted among various types of organic cocatalysts, considering their relative merits, cost implications, toxicity, and other pertinent factors. Finally, the review concludes by addressing the universal challenges and development prospects associated with organic co-catalytic systems. The overarching objective of this review is to provide insights into potential avenues for the future advancement of organic co-catalytic Fenton/Fenton-like reactions in the context of water purification.

Electrically enhanced adsorption efficiency of aluminum nitride nanotube for sulfate ion removal from water.

Herein, the adsorption performance of sulfate ion in water on aluminum nitride nanotube(AlNNT) under the influence of an electric field was investigated using the density functional theory (DFT) calculation method. The model structure stability, adsorption energy, electronic and thermodynamic properties of sulfate ion adsorbed on the surface of AlNNT were studied. The calculation results indicate that sulfate ion reacts with multi-atoms on the surface of AlNNT, forming ionic bonds and undergoing chemical adsorption. As the electric field intensity increases, the adsorption energy and the transfer of electrons from sulfate ion to AlNNT increase, leading to a higher degree of hybridization of atomic orbitals and enhanced multi-atom interactions. Additionally, the thermodynamic data suggests that the adsorption between sulfate ion and AlNNT under electric field can occur spontaneously, the process of which is exothermic. The results of present study are expected to propose a novel method for separation and removal of sulfate pollutants from water.

A Sodiophilic Amyloid Fibril Modified Separator for Dendrite-Free Sodium-Metal Batteries.

Sodium (Na) batteries are being considered as prospective candidates for the next generation of secondary batteries in contrast to lithium-based batteries, due to their high raw-material abundance, low cost, and sustainability. However, the unfavorable growth of Na-metal deposition and severe interfacial reactions have prevented their large-scale applications. Here, a vacuum filtration strategy, through amyloid-fibril-modified glass-fiber separators, is proposed to address these issues. The modified symmetric cell can be cycled for 1800 h, surpassing the performance of previously reported Na-based electrodes under an ester-based electrolyte. Moreover, the Na/Na3 V2 (PO4 )3 full cell with a sodiophilic amyloid-fibril-modified separator exhibits a capacity retention of 87.13% even after 1000 cycles. Both the experimental and the theoretical results show that the sodiophilic amyloid fibril homogenizes the electric field and Na-ion concentration, fundamentally inhibiting dendrite formation. Simultaneously, the glutamine amino acids in the amyloid fibril have the highest adsorption energy for Na, resulting in the formation of a stable Na3 N- and NaNx Oy -rich solid-electrolyte-interface film on the anode during cycling. This work provides not only a possible pathway to solve the dendrite problem in metal batteries using environmentally friendly biomacromolecular materials, but also a new direction for expanding biomaterial applications.

A comprehensive analysis of GAS2 family members identifies that GAS2L1 is a novel biomarker and promotes the proliferation of hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is a common primary liver cancer with a high incidence and mortality. Members of the growth-arresting-specific 2 (GAS2) family are involved in various biological processes in human malignancies. To date, there is only a limited amount of information available about the expression profile and clinical importance of GAS2 family in HCC. In this study, we found that GAS2L1 and GAS2L3 were distinctly upregulated in HCC specimens compared to non-tumor specimens. Pan-cancer assays indicated that GAS2L1 and GAS2L3 were highly expressed in most cancers. The Pearson's correlation revealed that the expressions of GAS2, GAS2L1 and GAS2L2 were negatively associated with methylation levels. Survival assays indicated that GAS2L1 and GAS2L3 were independent prognostic factors for HCC patients. Immune cell infiltration analysis revealed that GAS2, GAS2L1 and GAS2L3 were associated with several immune cells. Finally, we confirmed that GAS2L1 was highly expressed in HCC cells and its knockdown suppressed the proliferation of HCC cells. Taken together, our findings suggested the expression patterns and prognostic values of GAS2 members in HCC, providing insights for further study of the GAS2 family as sensitive diagnostic and prognostic markers for HCC.

Accurately recognizing chromium species with multi-functionalized nano Au-based sensor array.

High-resolution identification of chromium (Cr) species, especially various organic-Cr complexes, in a convenient and economically-feasible manner is the prerequisite for achieving the advanced treatment of chromium wastewater. To this end, a colorimetric nano-Au sensor array was developed by taking advantage of the UV-spectra shift of gold nanoparticles (Au NPs) upon interaction with Cr species; specifically, four molecular modifiers [i.e., iminodiacetic acid (IDA), tripolyphosphate (TPP), cetyltrimethylammonium bromide (CTAB), and 1,5-diphenylcarbazide (DPC)] were intentionally employed for assembling nano-Au array receptors, which showed respective responses toward different Cr species through the formation of coordination, hydrophobic interaction, electrostatic attraction, and redox reaction, respectively; the "fingerprint" differences of the unique optical properties were then integrated for semi-quantitatively recognizing Cr species by pattern recognition techniques. Eleven ubiquitous Cr species [i.e., Cr(III), Cr(VI), and various Cr(III)-organic complexes] served as the model samples, which could be sensitively identified, no matter in individual or mixture mode, by the developed nano-Au sensor array on the basis of the colorimetric responses resulted from diverse nano-Au-aggregation behaviors, with excellent anti-interference ability in the simulated or actual water scenario. Attractively, the nano-Au sensor array can achieve very sensitive detection limit of the quantitative analyses of Cr species in a prompt in-situ manner, which usually requires a two-step process of separation and detection for the conventional analytical methods. Such a convenient strategy of Cr species discrimination conduces to rationally designing specific protocols for the advanced treatment of chromium wastewater.

Efficient Removal and Recovery of Ag from Wastewater Using Charged Polystyrene-Polydopamine Nanocoatings and Their Sustainable Catalytic Application in 4-Nitrophenol Reduction.

This study addresses the long-standing challenges of removing and recovering trace silver (Ag) ions from wastewater while promoting their sustainable catalysis utilization. We innovatively developed a composite material by combining charged sulfonated polystyrene (PS) with a PDA coating. This composite serves a dual purpose: effectively removing and recovering trace Ag+ from wastewater and enabling reused Ag for sustainable applications, particularly in the catalytic reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP). The PS-PDA demonstrated exceptional selectivity to trace Ag+ recycling, which is equal to 14 times greater than the commercial ion exchanger. We emphasize the distinct roles of different charged functional groups in Ag+ removal and catalytic reduction performance. The negatively charged SO3H groups exhibited the remarkable ability to rapidly enrich trace Ag ions from wastewater, with a capacity 2-3 times higher than that of positively-N+(CH3)3Cl and netural-CH2Cl-modified composites; this resulted in an impressive 96% conversion of 4-NP to 4-AP within just 25 min. The fixed-bed application further confirmed the effective treatment capacity of approximately 4400 L of water per kilogram of adsorbent, while maintaining an extremely low effluent Ag+ concentration of less than 0.1 mg/L. XPS investigations provided valuable insights into the conversion of Ag+ ions into metallic Ag through the enticement of negatively charged SO3H groups and the in situ reduction facilitated by PDA. This breakthrough not only facilitates the efficient extraction of Ag from wastewater but also paves the way for its environmentally responsible utilization in catalytic reactions.

Few-Layer Meets Crystalline Structure: Collaborative Efforts for Improving Photocatalytic H2O2 Generation over Carbon Nitride.

Although the conversion of O2 and H2O to H2O2 over graphite carbon nitride (g-C3N4) has been realized by means of the photocatalytic process, the catalytic activity of pristine g-C3N4 is still restricted by the rapid charge recombination and inadequate exposure of the active site. In this work, we propose a straightforward strategy to solve these limitations by decreasing the thickness and improving the crystallinity of g-C3N4, resulting in the preparation of few-layered crystalline carbon nitride (FL-CCN). Benefiting from the minimal thickness and highly ordered in-plane triangular cavities within the structure, FL-CCN processes an extended π-conjugated system with a reduced charge transfer resistance and expanded specific surface area. These features accelerate the efficiency of photogenerated charge separation in FL-CCN and contribute to explore of its surface active sites. Consequently, FL-CCN exhibits a significantly improved H2O2 evolution rate (63.95 µmol g-1 h-1), which is 7.8 times higher than that of pristine g-C3N4 (8.15 µmol g-1 h-1), during the photocatalytic conversion of O2 and H2O. This systematic investigation offers valuable insights into the mechanism of photocatalytic H2O2 generation and the development of efficient catalysts.