Catalytic pyrolysis is a promising chemical recycling technology to supplement mechanical recycling since plastics can be broken down into monomers or converted to the required fuels and chemicals. In this study, a microwave (MW) -responsive SiC foam@zeoltie core-shell structured catalyst was proposed for the catalytic pyrolysis of polyolefins. Under microwave irradiation, the SiC foam core works as both microwave adsorber and catalyst support, thus concentrating the generated heat energy on the ZSM-5 zeolite shell, where the catalytic reaction takes place. SiC foam with an open cellular structure can also improve the global transport of mass and heat during plastics pyrolysis. In this work, the effects of the SiO₂/Al₂O₃ ratio and alkaline treatment of ZSM-5 zeolite coated SiC foam under MW irradiation on the variations in product distribution from low-density polyethylene (LDPE) pyrolysis were investigated at 450 °C. The results indicated that the appropriate acidity and pore structure were crucial to upgrading gas and liquid products. Particularly, the creation of a mesoporous structure in ZSM-5 zeolite via alkaline treatment could improve the diffusion of large molecules and products, thus significantly increasing the selectivity of high-valued light olefins and aromatics while inhibiting the formation of unwanted alkanes, which are expected in the chemical industry. Concretely, the concentration of olefins in gas increased to 51.0 vol% for ZSM-5(50)-0.25AT, and 65.6 vol% for ZSM-5 (50)-0.50AT, compared with 45.2 vol% for the parent ZSM-5(50). The relative concentration of aromatics in liquid decreased from 96.6% for ZSM-5(50) to 75.9% for ZSM-5(50)-0.25AT, and 71.1% for ZSM-5(50)-0.50AT. Given the respective yield of gas and liquid, the total selectivity of C2–C4 olefins and aromatics for mesoporous ZSM-5 zeolites could reach 58.6–64.9% during LDPE pyrolysis, which were higher than that for the parent ZSM-5 zeolite.

Dissolved organic matter (DOM) plays a significant role in the photochemical behavior of nano- and micro-plastic particles (NPs/MPs). We investigated the influence of DOM on the mechanism on the photoaging of NPs/MPs with different molecular structures under UV₃₆₅ irradiation in water. DOM components used in this study are mainly humic acid and fulvic acid. The results showed that DOM promoted the weathering of aliphatic NPs/MPs (polypropylene (PP)), but inhibited or had only a minor effect on the photoaging of aromatic NPs/MPs (polystyrene (PS) NPs/MPs, carboxyl-modified PS NPs, amino-modified PS NPs, and polycarbonate MPs). NPs with a large surface area may adsorb sufficient DOM on the particle surfaces through π-π interactions, which competes with NPs for photon absorption sites, thus, can delay the photoaging of PS NPs. Aromatic MPs may release phenolic compounds that quench •OH, thereby weakening the photoaging process. For aliphatic MPs, the detection of peracid, aldehyde, and ketone groups on the polymer surface indicated that DOM promoted weathering of PP MPs, which was primarily because the generation of •OH due to DOM photolysis may attack the polymer by C–C bond cleavage and hydrogen extraction reactions. This study provides insight into the UV irradiation weathering process of NPs/MPs of various compositions and structures, which are globally distributed in water.

Herein, an efficient visible-light-driven BiFeO₃/AgVO₃ nanocomposite was effectively fabricated via a facile co-precipitation procedure. The physicochemical properties of BiFeO₃/AgVO₃ nanocomposites were investigated via Fourier transform-infrared (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), photoluminescence (PL), UV visible diffuse reflectance spectroscopy (DRS) and photoelectrochemical studies (PEC). The photocatalytic activity (PCA) of BiFeO₃/AgVO₃ nanocomposites was assessed with regard to the photocatalytic degradation of Rhodamine-B (RhB) when subjected to visible light irradiation (VLI). Upon 90 min of illumination, the optimal 3%-BiFeO₃/AgVO₃ nanocomposite showed a greater photocatalytic degradation, which was ∼3 times higher than the bare AgVO₃. The lower PL intensity of 3%-BiFeO₃/AgVO₃ nanocomposite exposed the low recombination rate, which improved the photo-excited charge carriers separation efficiency. The experimental outcomes showed that the BiFeO₃/AgVO₃ nanocomposite might be an encouraging material for treatment of industrial and metropolitan wastewater. Moreover, a plausible RhB degradation mechanism was proposed proving the participation of the generated OH and O₂– radicals in the degradation over BiFeO₃/AgVO₃ nanocomposite.

In this study, heterojunction photocatalysts, XAg@C-TCZ, based on MOF-derived C–TiO₂ and Cd₀.₅Zn₀.₅S decorated with Ag nanoparticles (Ag NPs) were successfully synthesized through hydrothermal and calcination methods. The catalytic effectiveness of XAg@C-TCZ was evaluated by simultaneous photocatalytic degradation of rhodamine B (RhB) and reduction of Cr(VI) under simulated sunlight irradiation. The presence of the Z-scheme heterojunction was demonstrated through trapping experiments, X-ray photoelectron spectroscopy (XPS), time-resolved photoluminescence (PL) investigations, and electron spin resonance (ESR) spectroscopy. With an initial RhB and Cr(VI) concentration of 7 mg L⁻¹ and 5 mg L⁻¹, the catalyst 10Ag@C-TCZ achieved a simultaneous removal of 95.2% and 95.5% within 120 min, respectively. With the same catalyst, the degradation rate of RhB was 2.75 times higher and the reduction rate of Cr(VI) was 9.3 times higher compared to pure Cd₀.₅Zn₀.₅S. Total organic carbon (TOC) analysis confirmed the extent of mineralization of RhB, while the reduction of Cr(VI) was corroborated by XPS. Compared to pure RhB and Cr(VI) solutions, the reaction rates are smaller in the solution containing both contaminants, which is attributed to the competition for ·O₂⁻. 10Ag@C-TCZ also exhibited a stable catalytic performance in tap water and lake water. This work provides a new perspective on the construction of heterojunctions with doped MOF derivatives for the purification of complex pollutant systems.

Humans benefit from nuclear technologies but consequently experience nuclear disasters or side effects of iatrogenic radiation. Hematopoietic system injury first arises upon radiation exposure. As an intricate new layer of genetic control, the posttranscriptional m⁶A modification of RNA has recently come under investigation and has been demonstrated to play pivotal roles in multiple physiological and pathological processes. However, how the m⁶A methylome functions in the hematopoietic system after irradiation remains ambiguous. Here, we uncovered the time-varying epitranscriptome-wide m⁶A methylome and transcriptome alterations in γ-ray-exposed mouse bone marrow. 4 Gy γ-irradiation rapidly (5 min and 2 h) and severely impaired the mouse hematopoietic system, including spleen and thymus weight, blood components, tissue inflammation and malondialdehyde (MDA) levels. The m⁶A content and expression of m⁶A related enzymes were altered. Gamma-irradiation triggered dynamic and reversible m⁶A modification profiles and altered mRNA expression, where both m⁶A fold-enrichment and mRNA expression most followed the (5 min_up/2 h_down) pattern. The CDS enrichment region preferentially upregulated m⁶A peaks at 5 min. Moreover, the main GO and KEGG pathways were closely related to metabolism and the classical radiation response. Finally, m⁶A modifications correlated with transcriptional regulation of genes in multiple aspects. Blocking the expression of m⁶A demethylases FTO and ALKBH5 mitigated radiation hematopoietic toxicity. Together, our findings present the comprehensive landscape of mRNA m⁶A methylation in the mouse hematopoietic system in response to γ-irradiation, shedding light on the significance of m⁶A modifications in mammalian radiobiology. Regulation of the epitranscriptome may be exploited as a strategy against radiation damage.

In this work, we prepared nanocomposites of nickel-decorated manganese oxynitride on graphene nanosheets and demonstrated them as photocatalysts for degradation of acetylsalicylic acid (ASA). The catalyst exhibited a high degradation efficiency over ASA under visible light irradiation and an excellent structural stability after multiple uses. Compared to manganese oxide (MnO) and manganese oxynitride (MnON) nanoparticles, larger specific surface area and smaller band gap were observed for the nanocomposite accounting for the enhanced photocatalytic efficiency. Besides the compositional effect of the catalyst, we also examined the influence of various experimental parameters on the degradation of ASA such as initial concentration, catalyst dose, initial pH and additives. The best performance was obtained for the nanocomposite when the catalyst dose was 10 mg/mL and the initial pH 3. Detection of intermediates during photocatalysis showed that ASA undergoes hydroxylation, demethylation, aromatization, ring opening, and finally complete mineralization into CO₂ and H₂O by reactive species. For practical applications as a photocatalyst, cytotoxicity of the nanocomposite was also evaluated, which revealed its insignificant impact on the cell viability. These results suggest the nanocomposite of nickel-decorated manganese oxynitride on graphene nanosheets as a promising photocatalyst for the remediation of ASA-contaminated water.

Fabric and foam samples from popular children car seats marketed in the United States during 2018 were tested for fluorine content by particle-included gamma ray emission spectroscopy (PIGE, n = 93) and X-ray photoelectron spectroscopy (XPS, n = 36), as well as for per- and polyfluoroalkyl substances (PFAS) by liquid and gas chromatography mass spectrometry (LC/MS and GC/MS, n = 36). PFAS were detected in 97% of the car seat samples analyzed with MS, with total concentrations of 43 PFAS (∑PFAS) up to 268 ng/g. Fabric samples generally had greater ∑PFAS levels than foam and laminated composites of foam and fabric. The three fabric samples with the highest total fluorine content as represented by the highest PIGE signal were also subjected to ultraviolet (UV) irradiation and the total oxidizable precursor (TOP) assay. Results from these treatments, as well as the much higher organofluorine levels measured by PIGE compared to LC/MS and GC/MS, suggested the presence of side-chain fluorotelomer-based polymers (FTPs), which have the potential to readily degrade into perfluoroalkyl acids (PFAAs) under UV light. Furthermore, fluorotelomer (meth)acrylates were found to be indicators for the presence of (meth)acrylate-linked FTPs in consumer products, and thus confirmed that at least half of the tested car seats had FTP-treated fabrics. Finally, extraction of selected samples with synthetic sweat showed that ionic PFAS, particularly those with fluorinated carbons ≤8, can migrate from fabric to sweat, suggesting a potential dermal route of exposure.

The most promising technique for directly converting solar energy into clean fuels and environmental remediation by organic dye degradation is photoelectrochemical (PEC) process. We introduced Sn⁴⁺/Ti⁴⁺ doped α-Fe₂O₃@CuₓO heterojunction photoanode with complete optimization for PEC hydrogen (H₂) generation and organic dye degradation. Improvement of photocurrent photo and reducing overpotentials under optimized conditions lead to enhancing PEC performances, degradation efficiency of organic compounds, and H₂ generation generation rate. The optimized heterojunction photoanode (5TiFe@CuₓO-D) showed IPCE exceeding 42% compared with pristine hematite (Fe₀.₀₁–800₆ₕ) nanostructures (28%). Additionally, all the optimized photoanodes showed higher PEC stability for 10 h. Time-resolved PL spectra confirm the improved average lifetime for heterojunction photoanodes, supporting the enhanced PEC performance. Optimized 5TiFe@CuₓO-D material achieved PEC H₂ generation of ∼300 μL h⁻¹.cm⁻² which is two times higher than pristine hematite’s activity (150 μL h⁻¹.cm⁻²) and almost 99% degradation efficiency within 120 min of irradiation time. Therefore, a state-of-the-art study has been explored for hematite-based heterojunction photoanodes reflecting the superior PEC performance and hydrogen, methyl orange (MO) dye degradation activities. The improved results were reported because of stable morphology and better crystallinity acquired through systematic investigation of thermal effects and hydrothermal duration, improved electrical properties by Sn/Ti doping into the lattice of α-Fe₂O₃ and optimization of CuₓO deposition methods. The formation of well-defined heterojunction minimizes the recombination of the charge carrier and leads to effective transportation of excited electrons for the enhanced PEC performance.

Nitrous acid (HONO) production from the heterogeneous photochemical reaction of NO₂ on several Chinese soils was performed in a cylindrical reactor at atmospheric pressure. The NO₂ uptake coefficient (γ) and HONO yield (YHONO) on different soils were (0.42–5.16) × 10⁻⁵ and 6.3%–69.6%, respectively. Although the photo-enhanced uptake of NO₂ on different soils was observed, light could either enhance or inhibit the conversion efficiency of NO₂ to HONO, depending on the properties of the soils. Soils with lower pH generally had larger γ and YHONO. Soil organics played a key role in HONO formation through the photochemical uptake of NO₂ on soil surfaces. The γ showed a positive correlation with irradiation and temperature, while it exhibited a negative relationship with relative humidity (RH). YHONO inversely depended on the soil mass (0.32–3.25 mg cm⁻²), and it positively relied on the irradiance and RH (7%–22%). There was a maximum value for YHONO at 298 K. Based on the experimental results, HONO source strengths from heterogeneous photochemical reaction of NO₂ on the soil surfaces were estimated to be 0.2–2.7 ppb h⁻¹ for a mixing layer height of 100 m, which could account for the missing daytime HONO sources in most areas.

Herein, we report the optimization of nitrogen (N) doping in TiO₂ nanotubes to achieve the enhanced photocatalytic efficiencies in degradation of dye and H₂ gas evolution under solar light exposure. TiO₂ nanotubes have been produced via hydrothermal process and N doping has been tuned by varying the concentration of urea, being the source for N, by solid-state dispersion process. The structural analysis using XRD showed the characteristic occupancy of N into the structure of TiO₂ and the XPS studies showed the existence of Ti–N–Ti network in the N-doped TiO₂ nanotubes. The obtained TEM images showed the formation of 1D tube-like structure of TiO₂. Diffuse reflectance UV–Vis absorption spectra demonstrated that the N-doped TiO₂ nanotubes can efficiently absorb the photons of UV–Vis light of the solar light. The optimized N-doped TiO₂ nanotubes (TiO₂ nanotubes vs urea @ 1:1 ratio) showed the highest degradation efficiency over methyl orange dye (∼91% in 90 min) and showed the highest rate of H₂ evolution (∼19,848 μmol h⁻¹.g⁻¹) under solar light irradiation. Further, the recyclability studies indicated the excellent stability of the photocatalyst for the durable use in both the photocatalytic processes. The observed efficiency was ascribed to the optimized doping of N-atoms into the lattices of TiO₂, which enhanced the optical properties by forming new energy levels of N atoms near the valence band maximum of TiO₂, thereby increased the overall charge separation and recombination resistance in the system. The improved reusability of photocatalyst is attributed to the doping-induced structural stability in N-doped TiO₂. From the observed results, it has been recognized that the established strategy could be promising for synthesizing N-doped TiO₂ nanotubes with favorable structural, optical and photocatalytic properties towards dye degradation and hydrogen production applications.