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Publikation Modulating the electronic structure of Mn promotes singlet oxygen generation from electrochemical oxidation of H₂O via O-O coupling(Elsevier, 12/2024) Chen, Hao; Hou, Zhiang; Yue, Jinzhu; Wang, Jinnan; Wang, Yi; Li, Aimin; Corvini, PhilippeSelectively catalytic conversion H₂O into singlet oxygen (¹O₂) without additional oxidants is considered as an economic-efficient method for organic pollutants degradation. However, H₂O are more consistent with the spin state of ¹O₂ than common oxygen (O₂), retarding the kinetics of spin transition-induced reaction between O₂ and ¹O₂. Herein, we report an unprecedented ¹O₂ mediated electrocatalytic oxidation process, which allows O–O coupling for ¹O₂ evolution from H₂O over CrMn@C anode. The electron occupancy (eg) of CrMn@C (0.89) is very close to the optimal eg (0.95) of manganese-based materials reported in the literature, which facilitates the activation of H₂O on surface. Mn(Mn0.193Cr1.808)O₄-Mn in CrMn@C electrode significantly promotes the activation of H₂O to produce *O, followed by coupling of *O at adjacent sites to produce *OO, which further spontaneously forms ¹O₂. And H₂¹⁸O isotope experiments provide direct evidence for the production of ¹O₂ directly from H₂O. Consequently, the production of ¹O₂ is enhanced with the yield of 785.6 μmol·L⁻¹. Such ¹O₂-dominated electrocatalytic oxidation system can achieve efficient removal of electron-rich pollutant (bisphenol A) and improve the biodegradability of pharmaceutical wastewater (from 0.17 to 0.39).01A - Beitrag in wissenschaftlicher ZeitschriftPublikation Insecticide exposure alters flight-dependent gene-expression in honey bees, Apis mellifera(Elsevier, 12/2024) Christen, Verena; Jeker, Lukas; Lim, Ka S.; Menz, Myles H.M.; Straub, LarsThe increased reports of wild bee declines and annual losses of managed bees pose a significant threat to biodiversity and agricultural productivity. While these losses and declines are likely driven by various factors, the exposure of bees to agrochemicals has raised significant concern due to their ubiquitous use and potential adverse effects. Despite numerous studies suggesting neonicotinoids can negatively affect bees at the behavioral and molecular level, data linking these two factors remains sparse. Here we provide data on the impact of an acute dose of the neonicotinoid thiamethoxam on the flight performance and molecular transcription profiles of foraging honey bees (Apis mellifera). Using a controlled experimental design with tethered flight mills, we measured flight distance, duration, and speed, alongside the expression of genes involved in energy metabolism, hormone regulation, and biosynthesis. Acute thiamethoxam exposure resulted in hyperactive flight behavior but led to significant dysregulation of genes associated with oxidative phosphorylation, indicating potential disruptions in cellular energy production. These molecular changes were particularly evident when bees engaged in flight activities, suggesting that the combined stress of pesticide exposure and physical exertion exacerbates negative outcomes. Our study provides new insights into the molecular mechanisms underlying neonicotinoid-induced impairments in bee physiology that can help understand the potential long-term consequences of xenobiotic exposure on the foraging abilities of bees and ultimately fitness.01A - Beitrag in wissenschaftlicher ZeitschriftPublikation Bi atom sharing Co-Bi₂O₂CO₃/BiOI S-scheme induced singlet oxygen-dominated photocatalytic oxidation system(Elsevier, 12/2024) Hou, Zhiang; Yue, Jinzhu; Chen, Hao; Wang, Jinnan; Li, Aimin; Corvini, PhilippeEndocrine disrupting chemicals (EDCs) interfere with the normal secretion, transport and metabolism of human hormones, thus affecting neurological, reproductive and immune functions. Photocatalysis is regarded as a facile organic degradation technique. The construction of heterojunctions can modulate the reactive oxygen species and enhance the photocatalytic performance of semiconductors. However, poor contact interfaces still severely limit carrier separation and transfer. Herein, we have doped Co to modulate the band structure of Bi₂O₂CO₃ while facilitating the in situ growth of BiOI on its surface via shared Bi atoms. This approach led to the development of a 2D/2D Co-Bi₂O₂CO₃/BiOI (Co-BOC/BiOI) S-scheme heterojunction characterized by atomically close contact interfaces. Furthermore, the photo-electrochemical characterization results indicate that the light adsorption capacity, carrier separation and transport efficiency of the optimized Co-BOC/BiOI-3 are greatly improved. This system demonstrates almost 100% removal rate for three typical EDCs within 60 min. The degradation kinetic constants show an improvement by an order of magnitude compared to single BiOI and Bi₂O₂CO₃. More importantly, O₂•﹣, which is produced from O₂ reduction on high negative conduction band, can be subsequently oxidized into 1O2 by photogenerated hole. Electron paramagnetic resonance and quenching experiments indicate that the organics degradation process is dominated by 1O2. This work offers new insights into the construction of high-quality S-scheme heterojunction interfaces for modulation of reactive oxygen species.01A - Beitrag in wissenschaftlicher ZeitschriftPublikation Towards quantitative microplastic analysis using pyrolysis-gas chromatography coupled with mass spectrometry(Elsevier, 11/2024) Grafinger, Katharina Elisabeth; Ochiai, Celandin; Zhou, Huan-Xiao; Hettich, Timm; Büttler, Andre; Álvarez Troncoso, Romina; Zenker, Armin; Gaugler, StefanMicroplastic pollution from everyday plastic items has increased tremendously worldwide. Pyrolysis gas chromatography coupled to mass spectrometry (Py-GC/MS) has been widely investigated for the qualitative and quantitative analysis of microplastics in environmental samples. However, there are several pitfalls to consider when developing an appropriate protocol for their analysis. This study aimed at the development of an in-house database of primary (single) polymers, binary (two) polymers and tertiary (three) polymer mixtures. In this context the potential occurrence of gas phase reactions during pyrolysis of binary and tertiary polymers were investigated. Further, different diluters were tested for the accurate preparation of calibration standards for quantification purposes. Seven different polymers were included in this study, which were chosen due to their prevalence in daily plastic appliances. For each single polymer specific peaks could be identified and recommendation for quantifier analytes given. The analysis of binary polymer mixtures revealed gas phase reactions for PET with PVC, PVC with MDI-PU and PE with PVC. For these binary polymers, several different novel pyrolysis products, specific for the according binary polymer mixture, could be identified. These results confirmed that especially PVC exhibits strong interactions during co-pyrolysis with ester- and ether-based polymers. Similar results were obtained for tertiary polymers. For accurate preparation of calibration standards different diluters (silica, deactivated silica, calcium carbonate, THF and HFIP) were tested. It was observed that deactivated silica had only an influence on the pyrolysis of PET. Whereas, dilution with silica affected PA-6/66, PE, PET and MDI-PU. Only PVC was not influenced by dilution with silica. In conclusion, our results highlight the necessity of an international standard of reference material as well as a standardized analytical protocol for the analysis and quantification of polymers in environmental samples. It is crucial to use diluters suitable for the specific polymer, to exclude potential interactions of diluters with the polymer. The present work has to be seen as a foundation, but future work is needed to adequately address the quantification of polymers in environmental samples.01A - Beitrag in wissenschaftlicher ZeitschriftPublikation Maize (Zea mays L.) plants change their fate and accumulate non-extractable residues of sulfamethoxazole in the soil of arable land(American Chemical Society, 16.05.2024) Wu, Xuan; Sun, Feifei; Cao, Siqi; Wang, Qilin; Wang, Lianhong; Wang, Songfeng; He, Yan; Kolvenbach, Boris; Corvini, Philippe; Ji, RongThe fate of sulfonamide antibiotics in farmlands is crucial for food and ecological safety, yet it remains unclear. We used [phenyl-U-14C]-labeled sulfamethoxazole (14C-SMX) to quantitatively investigate the fate of SMX in a soil–maize system for 60 days, based on a six-pool fate model. Formation of nonextractable residues (NERs) was the predominant fate for SMX in unplanted soil, accompanied by minor mineralization. Notably, maize plants significantly increased SMX dissipation (kinetic constant kd = 0.30 day–1 vs 0.17 day–1), while substantially reducing the NER formation (92% vs 58% of initially applied SMX) and accumulating SMX (40%, mostly bound to roots). Significant NERs (maximal 29–42%) were formed via physicochemical entrapment (determined using silylation), which could partially be released and taken up by maize plants. The NERs consisted of a considerable amount of SMX formed via entrapment (1–8%) and alkali-hydrolyzable covalent bonds (2–12%, possibly amide linkage). Six and 10 transformation products were quantified in soil extracts and NERs, respectively, including products of hydroxyl substitution, deamination, and N-acylation, among which N-lactylated SMX was found for the first time. Our findings reveal the composition and instability of SMX-derived NERs in the soil–plant system and underscore the need to study the long-term impacts of reversible NERs.01A - Beitrag in wissenschaftlicher ZeitschriftPublikation Electrochemical reconfiguration of NiFe layered double hydroxide on BiVO4 induced by black phosphorus quantum dots for promoting photoelectrochemical water splitting(Elsevier, 12/2024) Sun, Yunshuyu; Chen, Hao; Hou, Zhiang; Wang, Jinnan; Li, Aimin; Corvini, PhilippeIn this work, black phosphorus quantum dots (BPQDs) and NiFe layered double hydroxide (NiFe-LDHs) were loaded on BiVO4 photoanode for promoting photoelectrochemical (PEC) water splitting. As a narrow bandgap p-type semiconductor with high work function, BPQDs could not only form p-n junction with BiVO4 to enhance light harvest but also construct Schottky junction for charge carriers separation. More importantly, introduction of BPQDs facilitates the transformation of Ni(OH)2 into NiOOH so as to improve the water oxidation capacity at low bias voltage. Density functional theory (DFT) calculation demonstrates that introduction of BPQDs accelerates the α/γ phase transition dynamically and thermodynamically, thus BiVO4/BPQDs/NiFe-LDHs photoanode achieves photocurrent density of 5.28 mA cm−2 at 1.23 VRHE, AM 1.5 G and maintains good stability. In summary, this work provides new ideas for constructing efficient hole extraction layers on photoelectrode, well expanding the application of BPQDs in PEC water splitting.01A - Beitrag in wissenschaftlicher ZeitschriftPublikation Manganese reductive dissolution coupled to Sb mobilization in contaminated shooting range soil(Springer, 10.04.2024) Costa, Lara; Martinez, Mathieu; Suleiman, Marcel; Keiser, Rolf; Lehmann, Moritz; Lenz, MarkusA “redox-stat” RMnR bioreactor was employed to simulate moderately reducing conditions (+ 420 mV) in Sb-contaminated shooting range soils for approximately 3 months, thermodynamically favoring Mn(IV) reduction. The impact of moderately reducing conditions on elemental mobilization (Mn, Sb, Fe) and speciation [Sb(III) versus Sb(V); Fe2+/Fe3+] was compared to a control bioreactor RCTRL without a fixed redox potential. In both bioreactors, reducing conditions were accompanied by an increase in effluent Sb(V) and Mn(II) concentrations, suggesting that Sb(V) was released through microbial reduction of Mn oxyhydroxide minerals. This was underlined by multiple linear regression analysis showing a significant (p < 0.05) relationship between Mn and Sb effluent concentrations. Mn concentration was the sole variable exhibiting a statistically significant effect on Sb in RMnR, while under the more reducing conditions in RCTRL, pH and redox potential were also significant. Analysis of the bacterial community composition revealed an increase in the genera Azoarcus, Flavisolibacter, Luteimonas, and Mesorhizobium concerning the initial soil, some of which are possible key players in the process of Sb mobilization. The overall amount of Sb released in the RMnR (10.40%) was virtually the same as in the RCTRL (10.37%), which underlines a subordinate role of anoxic processes, such as Fe-reductive dissolution, in Sb mobilization. This research underscores the central role of relatively low concentrations of Mn oxyhydroxides in influencing the fate of trace elements. Our study also demonstrates that bioreactors operated as redox-stats represent versatile tools that allow quantifying the contribution of specific mechanisms determining the fate of trace elements in contaminated soils. Key points • “Redox-stat” reactors elucidate Sb mobilization mechanisms • Mn oxyhydroxides microbial reductive dissolution has a major role in Sb mobilization in soils under moderately reducing conditions • Despite aging the soil exhibited significant Sb mobilization potential, emphasizing persistent environmental effects01A - Beitrag in wissenschaftlicher ZeitschriftPublikation No relationship between outputs of simple humus balance calculators (VDLUFA and STAND) and soil organic carbon trends(Wiley, 09/2024) Rainford, Shauna‐kay; Leifeld, Jens; Siegl, Sonja; Hagenbucher, Steffen; Riedel, Judith; Gross, Thomas; Niggli, Urs; Keel, Sonja G.Simple humus balance calculators were developed for farmers and consultants to determine the best crop rotation and amount of organic fertilizer required to improve soil quality and prevent nutrient leaching in croplands. Although the potential of these tools to infer the impact of different agricultural practices on soil organic carbon (SOC) dynamics in croplands is not well studied, they have been integrated in several farm-level climate or environmental impact assessment calculators. Here we examine the correlation between humus balance values estimated with two different tools developed in Germany/Central Europe and observed changes in SOC content at 14 long-term sites in Switzerland. The first tool was developed by the Association of German Agricultural Investigation and Research Institutes and is referred to as the VDLUFA. The humus balance calculator STAND is a descendent of the VDLUFA that accounts for pedoclimatic factors in Central Europe. Crop rotations were distinguished based on cultivation practice, whereby those with mixed fertilization were supplied with mineral fertilizer alone and in combination with organic materials, while those with organic fertilization include unfertilized and organic fertilizer treatments. An analysis of 133 short-term observations (i.e. individual crop rotations of five and 6-year duration) and 26 long-term observations (i.e. several crop rotations with a total duration of ≥10 years) showed that humus balance values (kg C ha−1 year−1) of short-term crop rotations were not or only poorly correlated with the observed change in SOC content (%) (R2 = 0.06 in STAND and R2 = 0.05 in VDLUFA for crop rotations with organic fertilization, and R2 < 0.01 for crop rotations with mixed fertilization). The correlation did not improve when the humus balance values of long-term observations with mixed fertilization were compared with decadal SOC development (R2 = 0.04 for STAND and R2 = 0.06 for the VDLUFA). Stronger correlations were found only for long-term observations with organic fertilization (R2 = 0.68 for STAND and R2 = 0.64 for the VDLUFA). These findings underline that while the studied humus balance calculators are able to distinguish the effect of different fertilizers (organic vs. mineral) on a farm's humus supply on the longer term, neither are suited for predicting SOC trends over single crop rotations. Although this study was carried out in Switzerland, the results should apply to any region with temperate climate and similar soil properties.01A - Beitrag in wissenschaftlicher ZeitschriftPublikation Amorphous metal-organic frameworks loaded on BiVO4 photoanodes with unique internal metal-like structure for promoting photoelectrochemical water splitting(Elsevier, 09/2024) Bai, Weihao; Li, Hao; Peng, Gang; Wang, Jinnan; Li, Aimin; Corvini, PhilippeAlthough ferrocene (Fc) based Metal-Organic Frameworks (MOFs) can act as oxygen evolution co-catalysts (OECs) for improvement of catalytic reactivity, the poor conductivity and lack of highly active metal sites limit its further application in photoelectrochemical (PEC) water splitting. Herein, the amorphous NiFc-MOF was grafted on BiVO4 photoanode (BiVO4@aNiFc-MOFs) for efficient PEC water splitting. This novel BiVO4@aNiFc-MOFs exhibits high current density of 4.34 mA cm−2 at 1.23 VRHE and relative low onset potential of 0.223 VRHE. The subsequent characterizations demonstrate that Ni species with metal-like state in bulk of aNiFc-MOFs form strong metal-support interaction with BiVO4, thereby promoting the interfacial charge transfer. Moreover, the surface of aNiFc-MOFs is short-range ordered with abundant coordinatively unsaturated Ni sites, creating a more favorable pathway for oxygen evolution reaction from thermodynamics. This work provides a simple method to design photoanodes with efficient OECs of amorphous MOFs for feasible PEC water splitting application.01A - Beitrag in wissenschaftlicher ZeitschriftPublikation Assessment of innovative wastewater technologies in India(Hochschule für Life Sciences FHNW, 2024) Rohrer, Karina; Hugi, Christoph; Pavitra Ganga11 - Studentische Arbeit