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Perovskite solar cells (PSCs) have shown rapid development recently, whereas nonideal stability remains the chief obstacle toward commercialization. Thus, it is of utmost importance to probe the degradation pathway for the entire device. Here, the extrinsic stability of inverted PSCs (IPSCs) is investigated by using standard shelf‐life testing based on the International Summit on Organic Photovoltaic Stability protocols (ISOS‐D‐1). During the long‐term assessment of 1700 h, the degraded power conversion efficiency is mainly caused by the fill factor (53% retention) and short‐circuit current density (71% retention), while the open‐circuit voltage still maintains 97% of the initial values. Further absorbance evolution and density functional theory calculations disclose that the perovskite rear‐contact side, in particular for the perovskite/fullerene interface, is the predominant degradation pathway. This study contributes to understanding the aging mechanism and enhancing the durability of IPSCs for future applications. [ABSTRACT FROM AUTHOR]

Understanding the radical behaviours during polymer degradation is beneficial to unveil and regulate the degradation pathways of polymers to achieve a sustainable polymer development. However, it is a long‐standing challenge to study radical behaviours owing to the ultra‐short lifetime of the transient radicals generated during the polymer degradation. In this contribution, we have proposed the radical‐triggered luminescence to monitor the radical behaviours during polymer degradation without/with the addition of inorganic additives. It was disclosed that the pure polymers showed a single sigmoidal dynamic curve from peroxy radicals (ROO⋅) emissions, leading to the exponential proliferation for the degradation evolution. Alternatively, the degradation pathways with the addition of additives, layered double hydroxides (LDHs) with positively charged Al centers, could be modulated into a double sigmoidal dynamics, involving the main product of alkoxy radicals (RO⋅) with the activation energy of 40.2 kJ/mol and a small amount of ROO⋅ with 76.3 kJ/mol, respectively. Accordingly, the polymers with the additive‐regulated pathways could exhibit prominently anti‐degradation behaviours. This work is beneficial for the deep understanding of the radical mechanisms during polymer degradation, and for the rational design of anti‐degradation polymers. [ABSTRACT FROM AUTHOR]

Ni‐rich layered oxides are one of the most attractive cathode materials in high‐energy‐density lithium‐ion batteries, their degradation mechanisms are still not completely elucidated. Herein, we report a strong dependence of degradation pathways on the long‐range cationic disordering of Co‐free Ni‐rich Li1−m(Ni0.94Al0.06)1+mO2 (NA). Interestingly, a disordered layered phase with lattice mismatch can be easily formed in the near‐surface region of NA particles with very low cation disorder (NA‐LCD, m≤0.06) over electrochemical cycling, while the layered structure is basically maintained in the core of particles forming a "core–shell" structure. Such surface reconstruction triggers a rapid capacity decay during the first 100 cycles between 2.7 and 4.3 V at 1 C or 3 C. On the contrary, the local lattice distortions are gradually accumulated throughout the whole NA particles with higher degrees of cation disorder (NA‐HCD, 0.06≤m≤0.15) that lead to a slow capacity decay upon cycling. [ABSTRACT FROM AUTHOR]

The key role of Cs cation and X halide anions (X = I, Br, Cl) on the microstructure, crystal structure, structural defects, optoelectronic properties, and photovoltaic parameters of FAPbI3‐based perovskite solar cells is investigated. The CsCl–FAPbI3 perovskite film shows the highest photoluminescence (PL) intensity, longest PL lifetime, and highest power conversion efficiency compared with the CsI–FAPbI3 and CsBr–FAPbI3 perovskite films. The morphology and crystallography of {111}c nanotwins and stacking faults of perovskite films are studied using transmission electron microscopy and selected‐area electron diffraction. The microstructure, crystallography, and atomic structure model of intersecting twin boundaries are presented. Finally, the degradation pathways and the mechanism behind the formation of FAPbI3‐based perovskites under ambient conditions are systematically studied. The grain boundaries of the perovskite films are nonuniformly damaged, resulting in many black nanoparticles after 4 weeks. Electron diffraction analyses of the black nanoparticles confirm the hexagonal PbI2 phase formation in all CsX–FAPbI3 perovskite samples after 4 weeks of aging. [ABSTRACT FROM AUTHOR]

In this study, the performance of ofloxacin (OFX) degradation in synthetic wastewater using synthesized MnOx‐CeOx/γ‐Al2O3 as a heterogeneous ozonation catalyst was evaluated. The removal rates of OFX and chemical oxygen demand (COD) during 15‐day continuous‐flow experiments were 98.2% and 76.7% on average, respectively. An ozone index (mgCOD/mgO3) of 1.09 with a high ozone utilization efficiency of 91.39% was achieved. The pseudo‐first‐order rate constant of ofloxacin degradation reached 15.216 × 10−2 min−1, which was five times that (3.085 × 10−2 min−1) without catalysts. The results of gas chromatography‐mass spectrometry (GC‐MS) demonstrated that a variety of small‐molecule organics occurred in the final oxidation products, such as 4‐hydroxyl‐4‐methyl‐2‐pentanone and 2‐oxoadipic acid in addition to homologs of OFX. The results of this study suggested that hydroxyl radicals played critical roles in the degradation and mineralization of OFX via four main pathways: (a) electrophilic addition of nitrogen; (b) breakdown of carbon‐carbon double bonds; (c) hydrolysis of ether rings; and (d) halodecarboxylation of carboxyl groups. The biodegradability (BOD5/COD) of OFX after catalytic ozonation reached 0.54. Practitioner points: Ofloxacin wastewater was treated using catalytic ozonation in a 15‐day continuous experiment with MnOx‐CeOx/γ‐Al2O3 as a catalyst.The ozone index reached 1.09 mgCOD/mgO3 during ozonation of ofloxacin.The presence of the catalyst increased the reaction rate constant by a factor of five.4‐hydroxy‐4‐methyl‐2‐pentanone was the primary ofloxacin oxidation product. [ABSTRACT FROM AUTHOR]

The study investigated the characteristics of aerobic degradation of tetrabromobisphenol A (TBBPA) by Irpex lacteus F17 (I. lacteus F17) under four different cometabolic substrates (phenol, glucose, sodium pyruvate, and sodium citrate). The biodegradation of TBBPA by I. lacteus F17 could be enhanced via cometabolism, and glucose (8 g/L) was confirmed to be the optimum carbon source. For different initial solution pH ranging from 3.0 to 8.0, the results showed that I. lacteus F17 could be applied to biodegrade TBBPA in a wide pH range of 4.0–8.0, and the degradation rate could reach the maximum 75.31%, while the debromination rate reached the maximum 12.40% under pH 5.0. In addition, it has been confirmed that Mn2+ (50 μmol/L) could promote the secretion of manganese peroxidase and TBBPA biodegradation efficiency. Seven intermediates were identified by gas chromatography–mass spectrometry analysis, and the possible degradation pathways were proposed, which indicated the biodegradation of TBBPA might be subjected to debromination, β‐scission, hydroxylation, deprotonation, and oxidation reactions. [ABSTRACT FROM AUTHOR]

Although power conversion efficiency (PCE) of polymer solar cells (PSCs) has exceeded 18%, the lifetime of PSCs is far away from satisfactory and has become the most critical issue before the commercialization of PSCs. Understanding the degradation mechanism and finding the proper way to suppress the degradation process are of high interests for PSC research. Polymer:fullerene solar cells (PFSCs) have a long research history and the working principle is well‐understood, so they are good models for the degradation mechanism study. This mini‐review summarizes the latest research progress of the PFSCs' degradation studies. Based on the results achieved, one can identify the extrinsic and intrinsic stress factors that cause different degradation processes. Degradation pathways of the PFSCs at different positions in the cells will be discussed in detail, including the electrode, the buffer layer, and the photoactive layer. Special emphasis will be put on various degradation processes of the photoactive layers. In the meantime, the methods to suppress the degradation processes will be presented accordingly. This mini‐review gives a comprehensive insight into the degradation mechanism and stability‐improvement strategies of PFSCs, which has important guiding significance for the stability‐improvement research of PSCs. [ABSTRACT FROM AUTHOR]

Peatlands, which store one third of the terrestrial carbon (C), are subject to large disturbances under a changing climate. It is crucial to understand how microbial and physiochemical factors affect the vulnerability of these large C stores to predict climate‐induced greenhouse gas fluxes. Here, we used a combination of mass spectrometry and spectroscopy techniques, to understand sequential biotic and abiotic degradation pathways of Sphagnum fallax leachate in an anaerobic incubation experiment, in the presence and absence of microorganisms. Removal of microorganisms was carried out by passing aqueous samples through 0.2‐µm filters. Our results revealed that S. fallax leachate degradation by abiotic reactions is a significant contributor to CO2 production. Further, abiotic factors, such as low pH, are responsible for partial dissolved organic carbon (DOC) degradation that produces bioavailable compounds that shift microbial metabolic pathways and stimulate respiration in peat bogs. Acid‐catalyzed hydrolysis of Sphagnum‐ produced glycosides can provide the microbial communities with glucose and stimulate microbial respiration of DOC to CO2. These results, while unique to peatlands, demonstrate the importance and underscore the complexity of sequential abiotic and biotic processes on C cycling in peat bogs. It is therefore crucial to incorporate abiotic degradation and sequential below‐ground biotic and abiotic interactions into climate models for a better prediction of the influence of climate change on DOC stability in peatlands. These findings might not be representative of other ecosystems with different environmental conditions including mineral‐rich peatlands and plant matter in surface peat horizons that comprise discrete microbial populations, and DOC composition. Plain Language Summary: Peatlands store a large amount of carbon (C) in its soil that can be released into the air as CO2. Microorganisms in peatland soil can utilize C and release it into the atmosphere. Abiotic influences (nonmicrobial), such as acidity, can also release C into the atmosphere by complete mineralization and/or by breaking it apart into simpler forms of C for microbial consumption. Here, we incubated dissolved organic carbon leachate from Sphagnum, a dominant vegetation in peatlands, for 70 days and removed microorganisms from one treatment. We found that with no microorganisms, carbon is being released to the air as CO2, and that without microorganisms more CO2 is being released overall. With microorganisms, C is being eaten and transformed differently by microorganisms before being released to the air, which only contributes to ∼10% of the CO2 released in our experiment. We also found that acidity could be cleaving larger forms of C to simpler forms, which these simple forms are more appealing to microorganisms to consume. Therefore, the importance of both abiotic (acidity) and biotic (microorganisms) influences on CO2 production from peatland soils should be considered when predicting ecosystem responses to climate change. Key Points: Abiotic reactions are a significant contributor to CO2 production in acidic peat bogsAcid‐catalyzed hydrolysis of complex molecules (e.g., glycosides) results in enhanced availability of glucose for microbial consumption in peat bogsAbiotic reactions shift microbial metabolic pathways and stimulate respiration in peat bogs [ABSTRACT FROM AUTHOR]

Methylammonium lead halide perovskite‐based solar cells have demonstrated efficiencies as high as 24.2 %, highlighting their potential as inexpensive and solution‐processable alternatives to silicon solar cell technologies. Poor stability towards moisture, ultraviolet irradiation, heat, and a bias voltage of the perovskite layer and its various device interfaces limits the commercial feasibility of this material for outdoor applications. Herein, we investigate the role of hydrogen bonding interactions induced when metal halide perovskite crystals are crosslinked with alkyl or π‐conjugated boronic acid small molecules (‐B(OH)2). The crosslinked perovskite crystals are investigated under continuous light irradiation and moisture exposure. These studies demonstrate that the origin of the interaction between the alkyl or π‐conjugated crosslinking molecules is due to hydrogen bonding between the ‐B(OH)2 terminal group of the crosslinker and the I of the [PbI6]4− octahedra of the perovskite layer. Also, this interaction influences the stability of the perovskite layer towards moisture and ultraviolet light irradiation. Morphology and structural analyses, as well as IR studies as a function of aging under both dark and light conditions show that π‐conjugated boronic acid molecules are more effective crosslinkers of the perovskite crystals than their alkyl counterparts thus imparting better stability towards light and moisture degradation. [ABSTRACT FROM AUTHOR]

Notoginsenoside Fc, a protopanaxadiol‐type saponin, shows multi‐pharmacological activities. Chemical stability evaluation plays a crucial role in drug development. In this study, the forced degradation behavior of Notoginsenoside Fc was investigated under hydrolytic and oxidative conditions. A specific ultra high performance liquid chromatography with quadrupole time‐of‐flight mass spectrometry was developed for the separation, identification, and characterization of the degradation products of Notoginsenoside Fc. Fifty potential degradation products were formed via deglycosylation, dehydration, hydration, isomerization, side‐chain cleaving, oxidation, and superoxidation. Notoginsenoside Fc was subjected to different pH solutions, temperatures, and time periods to assess its stability. A sensitive ultra high performance liquid chromatography‐tandem mass spectrometry was developed for the quantification of Notoginsenoside Fc, notoginsenoside ST‐4, notoginsenoside Ft1, and relative quantification of notoginsenoside Ft2, 20(R)‐notoginsenoside Ft2, notoginsenoside SFt3, and notoginsenoside SFt4. The assay was linear over the concentration range (R2 > 0.997) with the lowest limit of quantification of 0.02 μg/mL for Notoginsenoside Fc, Notoginsenoside ST‐4, and Notoginsenoside Ft1. The intra‐day precision, inter‐day precision, and accuracy of the three analytes were within accepted levels. The degradation kinetics of Notoginsenoside Fc in pH 1 and 3 solutions fits to first‐ and second‐order kinetics, respectively. The degradation of Notoginsenoside Fc is pH‐, temperature‐, and time‐dependent. [ABSTRACT FROM AUTHOR]

Herein, we report the comparison of two different mixing methods for reductive dechlorination of gamma‐hexachlorocyclohexane (γ‐HCH), aldrin, and p, p'‐dichlorodiphenyl‐trichloroethane (p, p'‐DDT), using iron/palladium (Fe/Pd) bimetallic nanoparticles. A noticeable enhancement of the reaction rate was found when the reductive dechlorination reaction was carried out in an ultrasound bath as compared with a platform shaker. These enhancements could be attributed to (a) the continuous cleaning and chemical activation of the surfaces of nanoscale Fe/Pd bimetallic nanoparticles by the combined chemical and physical effects of acoustic cavitation; and (b) the accelerated mass transport rates of target POPs to the surfaces of the Fe/Pd nanoparticles. Finally, the degradation intermediates and final products were determined by gas chromatography/mass spectrometry (GC/MS) analysis and the plausible degradation pathways for γ‐HCH, aldrin, and p, p'‐DDT by Fe/Pd bimetallic nanoparticles were proposed. Practitioner points: Exposure to POPs is a resilient global environmental and health issue.Fe/Pd bimetallic nanoparticles demonstrated > 90 % removal of POPs in the first 30 minutes of the reaction via ultrasonic mixing.GC‐MS analyses provided verification of POPs degradation intermediates and final products. [ABSTRACT FROM AUTHOR]

In the present study, biodegradation of monochlorophenols (MCPs) and their co-metabolism with 2,4-dichlorophenol (2,4-DCP) using mixed microbial consortium has been reported. The mixed consortium has shown 44 to 100% degradation of 50 to 300 mg L-1 3-chlorophenol (3-CP). While in case of 4-CP, the degradation observed was 46 to 100% of 100 to 600 mg L−1 of initial concentrations. HPLC and spectrophotometric analysis indicated that the degradation occurred via a meta-cleavage pathway. 4-Chlorocatechol was observed as a common intermediate for both 3-CP and 4-CP degradation pathways. The transformation of 4-chlorocatechol to maleylacetate via 5-chloro 2-hydroxymuconic semialdehyde indicated the complete degradation of both 3-CP and 4-CP. The co-metabolic study of 2,4-DCP in the presence of MCPs showed that the degradation of 2,4-DCP increases in the presence of 3-CP and 4-CP. The biodegradation (mg L−1 per day) in the quaternary mixture of MCPs and DCP occurred in the order of 3-CP > 4-CP > DCP > 2-CP. The biodegradation kinetics constants obtained for 3-CP were Rm = 1.96 mg L−1 h−1, Ks = 47.23 mg L−1, Ki = 104.12 mg L−1, and for 4-CP were Rm = 6.33 mg L−1 h−1, Ks = 1262 mg L−1, Ki = 1408.8 mg L−1 by Andrew's substrate inhibition model using MATLAB 6.5. [ABSTRACT FROM AUTHOR]

Cationic Disordering, Degradation Pathways, Lattice Distortion, Ni-Rich Cathodes, Surface Reconstruction Keywords: Cationic Disordering; Degradation Pathways; Lattice Distortion; Ni-Rich Cathodes; Surface Reconstruction EN Cationic Disordering Degradation Pathways Lattice Distortion Ni-Rich Cathodes Surface Reconstruction 1 1 1 03/09/23 20230313 NES 230313 B Batteries b . In their Research Article (e202214880), Weibo Hua, Wei Tang, Sylvio Indris, Xiaodong Guo et al. synthesized a series of Ni-rich Li(NiAl)O SB 2 sb oxides through tailoring the heating temperature. [Extracted from the article]

BACKGROUND A new method of malachite green ( MG) degradation by dielectric barrier discharge ( DBD) plasma with an Ag3PO4/ TiO2 composite photocatalyst was investigated. Ag3PO4/ TiO2 was synthetized by an in situ precipitation method under room conditions, and analyzed by XRD, SEM, TEM, XRF and BET. The catalytic activity, the reaction mechanisms, the intermediates of MG degradation and the proposed degradation pathways were also evaluated. RESULT The efficiency of degradation of 150 mL of MG with initial concentration 150 mg L−1 was improved from 80.9% to 94.2% in 14 min at input power of 80 W relative to the Ag3PO4/ TiO2 cooperated as 0.05 g. Meanwhile, the TOC removal rate increased from 13.9% to 20.6%. CONCLUSIONS It was shown that a synergistic effect existed between DBD plasma and Ag3PO4/ TiO2 in the process of MG degradation. Higher input power, larger initial concentration and narrower air-gap distance caused Ag3PO4/ TiO2 to show even better effects in the DBD system, improving degradation efficiency and energy yield. Possible MG degradation pathways involved a series of deamination, denitrosation, demethylation, hydroxylation and oxidative openings of the aromatic ring processes. The study proposed an efficient technology and degradation mechanisms for MG wastewater treatment. © 2015 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Nitrogen-containing polycyclic aromatic hydrocarbons are very attractive compounds for organic electronics applications. Their low-lying LUMO energies points towards a potential use as n-type semiconductors. Furthermore, they are expected to be more stable under ambient conditions, which is very important for the formation of semiconducting films, where materials with high purity are needed. In this study, the syntheses of naphtho[2,3- g]quinoxalines and pyrazino[2,3- b]phenazines is presented by using reaction conditions, that provide the desired products in high yields, high purity and without time-consuming purification steps. The HOMO and LUMO energies of the compounds are investigated by cyclic voltammetry and UV/Vis spectroscopy and their dependency on the nitrogen content and the terminal substituents are examined. The photostability and the degradation pathways of the naphtho[2,3- g]quinoxalines and pyrazino[2,3- b]phenazines are explored by NMR spectroscopy of irradiated samples affirming the large influence of the nitrogen atoms in the acene core on the degradation process during the irradiation. Finally, by identifying the degradations products of 2,3-dimethylnaphtho[2,3- g]quinoxaline it is possible to track down the most reactive position in the compound and, by blocking this position with nitrogen, to strongly increase the photostability. [ABSTRACT FROM AUTHOR]

The present work was focused on the investigation of the original and decayed materials as well as the degradation phenomena affecting the middle age mural painting preserved in the Assumption's church of Alaiza (Basque Country, Spain). Portable Raman spectroscopy assisted with energy dispersive X-ray fluorescence was used to identify the nature of the original compounds and to distinguish them from the following: (1) those used in recent restorations and (2) those considered as decaying compounds. The information obtained by this technique was used to select the sampling areas to perform laboratory Raman measurements and soluble salt test, supported by the use of ion chromatography in an attempt to clarify the degradation processes of the mural paintings. These analyses suggested the connection of the deterioration problems with the agricultural activity of the environment surrounding the church. For example, the use of industrial common salt (unpurified NaCl) against the snow and ice, as well as common fertilizers such as NH4NO3 and (NH4)2SO4, generates Na+ and NH4+ cations together with Cl−, NO3−, and SO42−anions that ascent the basal part of the walls causing the decarbonation of calcite and the subsequent disintegration of the mortar. Sulfate compounds were detected in the lower parts of the walls (below half a meter), while nitrate compounds were detected in the higher parts, at heights greater than 1 m. This work is a clear example of the conservation problems in cultural heritage related to the characteristics of the surrounding environment. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]