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Sweet potato ( Ipomoea batatas ) serves as a significant food and economic crop worldwide. However, its production and safety are jeopardized by black rot, a disease caused by Ceratocystis fimbriata . Although polyamines (PAs) are common biological growth factors, their function in the storage of fruits and vegetables remains poorly understood. This study examines the physiological roles of both exogenous and endogenous PAs in C. fimbriata , particularly their metabolism via gene knockout techniques. Additionally, we assessed how exogenous PAs affect sweet potato storage resistance. Our findings reveal that PAs are crucial in managing oxidative and cell wall stress in C. fimbriata . At high concentrations, PAs displayed cytotoxic effects through the upregulation of nitric oxide synthase ( TAH18 ). Furthermore, exogenous PAs significantly enhanced the defense mechanisms of sweet potatoes during storage. The concurrent use of perillaldehyde (PAE), a natural antibacterial compound, additionally decreased the incidence of black rot in sweet potatoes. This study provides a novel strategy and theoretical basis for the prevention and control of fungal diseases in stored fruits and vegetables.

Selective removal of the nitrogen atom from an aromatic N -heterocycle, such as pyridine, is of significant interest and importance, yet it remains highly challenging. Here, we report an unprecedented denitrogenative ring-contraction reaction of pyridines at a dititanium hydride framework, yielding cyclopentadienyl and nitride species under mild conditions. The reaction of pyridine with a dititanium tetrahydride complex ( 1 ) bearing rigid acridane-based PNP-pincer ligands at room temperature produced a cyclopentadienyl/nitride complex ( 2 ), in which the two Ti atoms are bridged by a nitride atom and one Ti atom is bonded to a cyclopentadienyl group formed by pyridine denitrogenation and ring-contraction. The reactions of 2-, 3-, and 4-methylpyridines with 1 under similar conditions yielded the same product ( 3 ), a methylcyclopentadienyl-ligated analog of 2 . When 2,4- or 3,5-dimethylpyridine reacted with 1 at 60 °C, the 1,3-dimethylcyclopentadienyl-ligated analog ( 5 ) formed almost quantitatively. The mechanistic details have been elucidated by isolation of key intermediates and density functional theory calculations. It was revealed that the reaction proceeded via coordination of the N atom of a pyridine unit to a Ti atom in 1 followed by H 2 release, C═N reduction, two C-N bond cleavage (ring-opening and denitrogenation), and C-C coupling (ring closing). The involvement of C-H activation in an isopropyl group of a PNP ligand at the later stages of the reaction significantly contributed to the stabilization of the denitrogenative ring-contraction product. This work not only provides unprecedented mechanistic insights into denitrogenation of aromatic N -heterocycles but also represents a novel example of skeletal editing of aromatic N -heterocycles.

The isomerization of 1,1-disubstituted alkenes through 1,3-hydrogen shift is an atom-efficient route for synthesizing trisubstituted alkenes, which are important moieties in many natural products, pharmaceuticals, and organic materials. However, this reaction often encounters regio- and stereoselectivity challenges, typically yielding E / Z -mixtures of the alkene products or thermodynamically favored ( E )-alkenes. Herein, we report the ( Z )-selective isomerization of 1,1-disubstituted alkenes to trisubstituted ( Z )-alkenes via the regio- and stereospecific activation of an allylic C-H bond. The key to the success of this unprecedented transformation is the use of a sterically demanding half-sandwich scandium catalyst in combination with a bulky quinoline compound, 2- tert -butylquinoline. Deuterium-labeling experiments and density functional theory (DFT) calculations have revealed that 2- tert -butylquinoline not only facilitates the C═C bond transposition through hydrogen shuttling but also governs the regio- and stereoselectivity due to the steric hindrance of the tert -butyl group. This protocol enables the synthesis of diverse ( Z )-configured acyclic trisubstituted alkenes and endocyclic trisubstituted alkenes from readily accessible 1,1-disubstituted alkenes. It offers an efficient and selective route for preparing a new family of synthetically challenging ( Z )-trisubstituted alkenes with broad substrate scope, 100% atom efficiency, high regio- and stereoselectivity, and an unprecedented reaction mechanism.

Dinitrogen (N 2 ) activation and functionalization through N-N bond cleavage and N-C bond formation are of great interest and importance but remain highly challenging. We report here for the first time N 2 cleavage and selective multicoupling with isocyanides in a dititanium dihydride framework. The reaction of a dinitrogen dititanium dihydride complex [{( acri PNP)Ti} 2 (μ-η 1 :η 2 -N 2 )(μ-H) 2 ] ( 1 ) with an excess (four or more equivalents) of p -methoxyphenyl isocyanide at room temperature gave a novel amidoamidinatoguanidinate complex [( acri PNP)Ti{NC(═NR)NC(═NR)CH 2 NR}Ti( acri PNP)(CNR)] ( 2 , acri PNP = 4,5-bis(diisopropylphosphino)-2,7,9,9-tetramethyl-9 H -acridin-10-ide; R = p -MeOC 6 H 4 ) through N 2 splitting and coupling with three isocyanide molecules. When 1 equiv of p -methoxyphenyl isocyanide was used to react with 1 at -30 °C, the hydrogenation of the isocyanide unit by the two hydride ligands in 1 took place, affording an amidomethylene-bridged dititanium dinitrogen complex [{( acri PNP)Ti} 2 (μ-η 1 :η 2 -N 2 ){μ-η 1 :η 2 -CH 2 N( p -MeOC 6 H 4 )}] ( 3 ), which upon reaction with another equivalent of p -methoxyphenyl isocyanide at room temperature gave an amidomethylene/nitrido/carbodiimido complex [( acri PNP)Ti(N═C═NR)(μ-N)(μ-η 1 :η 2 -CH 2 NR)Ti( acri PNP)] ( 4 ) through N 2 cleavage and N═C bond formation. Further reaction of 4 with 1 equiv of p -methoxyphenyl isocyanide led to an unprecedented four-component (carbodiimido, nitrido, isocyanide, and amidomethylene) coupling, yielding an amidoamidinatoguanidinate complex [{( acri PNP)Ti} 2 {NC(═NR)NC(═NR)CH 2 NR}] ( 5 ), which on reaction with another equivalent of p -methoxyphenyl isocyanide afforded the isocyanide-coordinated analogue 2 . The reaction of 1 with 2-naphthyl isocyanide also took place in a similar multicoupling fashion. Moreover, the cross-coupling reactions of the p -methoxyphenyl isocyanide-derived amidomethylene/nitrido/carbodiimido complex 4 with 2-naphthyl isocyanide, cyclohexyl isocyanide, and tert -butyl isocyanide were also achieved, which afforded the corresponding amidoamidinatoguanidinate products consisting of two different isocyanides. Density functional theory (DFT) calculations further elucidated the mechanistic details.

The [3 + 2] or [4 + 2] annulation of α,β-unsaturated aldimines with alkenes via β'- or γ-allylic C(sp 3 )-H activation is, in principle, an atom-efficient route for the synthesis of five- or six-membered-ring cycloalkylamines, which are important structural motifs in numerous natural products, bioactive molecules, and pharmaceuticals. However, such a transformation has remained undeveloped to date probably due to the lack of suitable catalysts. We report herein for the first time the regio- and diastereoselective [3 + 2] and [4 + 2] annulations of α,β-unsaturated imines with alkenes via allylic C(sp 3 )-H activation by half-sandwich rare-earth catalysts having different metal ion sizes. The reaction of α-methyl-substituted α,β-unsaturated aldimines with alkenes by a C 5 Me 4 SiMe 3 -ligated scandium catalyst took place in a trans -diastereoselective [3 + 2] annulation fashion via C(sp 3 )-H activation at the α-methyl group (β'-position), exclusively affording alkylidene-functionalized cyclopentylamines with excellent trans -diastereoselectivity. In contrast, the reaction of β-methyl-substituted α,β-unsaturated aldimines with alkenes by a C 5 Me 5 -ligated cerium catalyst proceeded in a cis -diastereoselective [4 + 2] annulation fashion via γ-allylic C(sp 3 )-H activation, selectively yielding multisubstituted 2-cyclohexenylamines with excellent cis -diastereoselectivity. The mechanistic details of these transformations have been elucidated by deuterium-labeling experiments, kinetic isotope effect studies, and the isolation and transformations of key reaction intermediates. This work offers an efficient and selective protocol for the synthesis of a new family of cycloalkylamine derivatives, featuring 100% atom efficiency, high regio- and diastereoselectivity, broad substrate scope, and an unprecedented reaction mechanism.

Ozone was injected into a coal-water suspension, and an HRTEM test was carried out on the separated oxidation products. The results show that from the perspective of visualization the macromolecular network structure of coal contains a large number of graphite-like structures. However, the chemical reaction mechanism between the coal surface and O 3 is not clear, and the microscopic formation mechanism of oxygen-containing functional groups in carbon quantum dots has not been explained. As a result, the reaction process between O 3 and methylene on the coal surface was studied by the DFT method. We found that OH• generated by O 3 in water can oxidize two adjacent carbon atoms in methylene into double bonds (C=C), and finally, aldehydes and carboxylic acids were generated. By calculation of thermodynamic parameters Δ G and Δ H , it is found that all reactions are spontaneous exothermic processes. The above chemical reaction is based on the physical adsorption of OH• with Ar-(CH 2 ) 6 -Ar and O 3 with Ar-CH 2 -CH=CH-(CH 2 ) 3 -Ar. The calculated adsorption energies of the two systems are -9.41 and -12.55 kcal/mol, respectively. Then, the charge transfer and atomic orbital interaction before and after adsorption are analyzed from the perspectives of Mulliken charge, density of states, deformation density, and total charge density. The results show that the electrostatic attraction is the main driving force of adsorption. The ether bond (C-O-C) in coal is finally oxidized to an ester group (RCOOR'), the hydroxyl group (CH 2 -CH-OH) on the aliphatic chain is oxidized to a carbonyl group (CH 2 -C=O), and the benzene with two OH• forms phenol hydroxyl and one molecule of water. Finally, the coal and the corresponding coal-based carbon quantum dots were investigated by infrared spectroscopy; the difference in functional groups before and after oxidation was clarified, and the result was in good agreement with the simulation., Competing Interests: The authors declare no competing financial interest., (© 2023 The Authors. Published by American Chemical Society.)

The direct use of dinitrogen (N 2 ) as a building block for the synthesis of NN-containing organic compounds is of fundamental interest and practical importance but has remained a formidable challenge to date. Here, we report an unprecedented 1,4-conjugate (aza-Michael) addition of N 2 to α,β-unsaturated carbonyl compounds in a dititanium framework. The resulting hydrazinopropenolate products could be easily converted to diverse NN-containing organic compounds such as β-hydrazine-functionalized esters and amides, pyrazolidinones, and pyrazolines depending on the types of Michael acceptors through protonation with MeOH. Further transformations of a hydrazinopropenolate titanium complex through C-C and N-C bond formations with electrophiles such as CO 2 and benzaldehyde have also been achieved. The mechanistic details of the N 2 addition reaction have been elucidated by computational studies, revealing the importance of redox-active metal centers in this event. This work showcases the potential of using N 2 as a building block for the synthesis of NN-containing organic compounds through activation and functionalization in a molecular metal framework.

The activation and functionalization of dinitrogen (N 2 ) with carbon dioxide (CO 2 ) are of great interest and importance but highly challenging. We report here for the first time the reaction of N 2 with CO 2 in a dititanium dihydride framework, which leads to N-C bond formation and N-N and C-O bond cleavage. Exposure of a dinitrogen dititanium hydride complex {[( acri PNP)Ti] 2 ( μ 2 - η 1 : η 2 -N 2 )( μ 2 -H) 2 } ( 1 ) ( acri PNP = 4,5-bis(diisopropylphosphino)-2,7,9,9-tetramethyl-9H-acridin-10-ide) to a CO 2 atmosphere at room temperature rapidly yielded a nitrido/ N , N -dicarboxylamido complex {[( acri PNP)Ti] 2 ( μ 2 -N)[ μ 2 -N(CO 2 ) 2 ]} ( 2 , 28%) and a diisocyanato/dioxo complex {[( acri PNP)Ti] 2 (NCO) 2 ( μ 2 -O) 2 } ( 3 , 52%) with release of H 2 . When the reaction of 1 with CO 2 (1 atm) was carried out at -50 °C, complex 2 was selectively formed in 82% yield within 5 min. Heating 2 at 80 °C under 1 atm CO 2 for 30 min afforded 3 in 67% yield. When 1 was allowed to react with 1.5 equiv of CO 2 at room temperature, an isocyanato/nitrido/oxo complex {[( acri PNP)Ti] 2 (NCO)( μ 2 -N)( μ 2 -O)} ( 4 ) was exclusively formed in 89% yield within 5 min. The reaction of 4 with CO 2 at room temperature almost quantitatively yielded the dioxo/diisocyanato complex 3 within 5 min. The mechanistic details were clarified by the 15 N- and 13 C-labeled experiments and density functional theory (DFT) calculations, providing unprecedented insights into the reaction of N 2 with CO 2 . A titanium-mediated cycle for the synthesis of trimethylsilyl isocyanate Me 3 SiNCO from N 2 , CO 2 , and Me 3 SiCl using H 2 as a reducing agent was also established.

The Lower Jurassic reservoir has recently made a significant breakthrough in petroleum exploration in the Tugerming area of the eastern Kuqa depression, Tarim Basin, northwest China. Therefore, it is significantly essential to simulate the hydrocarbon charging process and analyze the accumulation mechanism in the study area. In our study, we mainly combine three geochemical techniques to identify the origin of crude oils and fluid inclusion characteristics in the target well (Tudong 2), including gas chromatography-mass spectrometry (GC-MS), comprehensive two-dimensional GC-time-of-flight MS (GC × GC-TOFMS), fluid inclusion analysis, and quantitative fluorescence technique. Combined comprehensive experiments with a set of burial history and tectonic thermal evolution history realize the reconstruction of the hydrocarbon charging process in the Yangxia formation. The results show that Jurassic coal-bearing source rocks are primary hydrocarbon sources, and there are three hydrocarbon charging events in the Lower Jurassic reservoir. First, the mature oils have expelled into the reservoir during the early-middle period (15-10 Ma) of the Miocene Kangcun Formation, forming yellow fluorescent oil inclusions and most of the quantitative grain fluorescence (QGF) indexes exceed 4. Second, numerous condensate oils have charged into the reservoir in the period of late Miocene Kangcun Formation-early Kuqa Formation (9-6 Ma), accompanied by blue-white oil inclusions and QGF on extract intensity greater than 4. Finally, vast natural gas has accumulated in the reservoir since Kuqa Formation (5-0 Ma), resulting in the adjustment of ancient reservoir and residual bitumen. Interestingly, we find that the hydrocarbon accumulation mechanism is characterized by self-generation and self-storage in the Jurassic Yangxia Formation, and the study area has prominent characteristics of late accumulation. Thus, the evidence obtained from our analysis suggests favorable geological conditions for the formation of a large oil and gas reservoir in the eastern Kuqa Depression., Competing Interests: The authors declare no competing financial interest., (© 2021 The Authors. Published by American Chemical Society.)

Attachment behavior is a key component of flotation and has a decisive influence on flotation performance, and the experiment research on the attachment between mineral particles and bubbles still needs further research. In this work, a particle-bubble attachment apparatus and multiple target tracking software were developed. Coal particles were used as the subjects, and the effect of particle properties on the attachment performance was studied from the perspective of the particle group. The particle-bubble attachment experiments indicated that the collision position had an effect on the attachment efficiency, and the attachment efficiency decreased with an increase in the collision angle. The efficiency-weighted attachment angle was proposed to quantitatively describe the attachment performance of coal samples. The efficiency-weighted attachment angle of low-density coal samples was greater than that of high-density coal samples. For particles with different sizes, the efficiency-weighted attachment angle of fine particles was greater than that of coarse particles. Furthermore, SDS weakened the attachment performance between coal particles and bubbles via adsorption on the bubble, and the efficiency-weighted attachment angle decreased as the concentration of the SDS solution increased. CTAB adsorbed on coal particles and bubbles, and the efficiency-weighted attachment angle first increased and then decreased with increasing CTAB concentration., Competing Interests: The authors declare no competing financial interest., (© 2021 American Chemical Society.)

The enantioselective C-H alkenylation of ferrocenes with alkynes is, in principle, a straightforward and atom-efficient route for the construction of planar-chiral ferrocene scaffolds bearing alkene functionality but has remained scarcely explored to date. Here we report for the first time the highly enantioselective C-H alkenylation of quinoline- and pyridine-substituted ferrocenes with alkynes by a half-sandwich scandium catalyst. This protocol features broad substrate scope, high enantioselectivity, and 100% atom efficiency, selectively affording a new family of planar-chiral ferrocenes bearing N /alkene functionalities. The mechanistic details have been clarified by DFT analyses. The use of a quinoline/alkene-functionalized ferrocene product as a chiral ligand for asymmetric catalysis is also demonstrated.

Solar water splitting is one of the most efficient technologies to produce H 2 , which is a clean and renewable energy carrier. Photoanodes for water oxidation play the determining roles in solar water splitting, while its photoelectrochemical (PEC) performance is severely limited by the hole injection efficiency at the interface of semiconductor/electrolyte. To address this problem, in this research, by employing BiVO 4 as the model semiconductor for photoanodes, we develop a novel, facile, and efficient method, which simply applies K cations in the preparation process of BiVO 4 photoanodes, to in situ induce a crystalline-amorphous heterophase junction by the formation of an amorphous BiVO 4 layer (a-BiVO 4 ) on the surface of the crystalline BiVO 4 (c-BiVO 4 ) film for PEC water oxidation. The K cation is the key to stimulate the formation of the heterophase, but not incorporated in the final photoelectrodes. Without sacrificing the light absorption, the in situ formed a-BiVO 4 layer accelerates the kinetics of the hole transfer at the photoanode/electrolyte interface, leading to the significantly increased efficiency of the surface hole injection to water molecules. Consequently, the BiVO 4 photoanode with the crystalline-amorphous heterophase junction (a-BiVO 4 /c-BiVO 4 ) exhibits almost twice the photocurrent density at 1.23 V (vs reversible hydrogen electrode) for water oxidation than the bare c-BiVO 4 ones. Such advantages from the crystalline-amorphous heterophase junction are still effective even when the a-BiVO 4 /c-BiVO 4 is coated by the cocatalyst of FeOOH, reflecting its broad applications in PEC devices. We believe this study can supply an efficient and simple protocol to enhance the PEC water oxidation performance of photoanodes, and provide a new strategy for the potential large-scale application of the solar energy-conversion related devices.

The genetically modified maize carrying an insect-resistant gene and herbicide-tolerant gene has substantial benefits for crop production. The three-generation reproductive toxicity of the maize was studied in this paper. One hundred and eighty Sprague-Dawley (SD) rats were divided into three groups, which were fed with a genetically modified maize (GM) diet, receptor maize (RM) diet, and AIN-93G (AIN) diet (used as control), respectively. The body weight, food consumption, reproductive parameters, hematological parameters, serum chemistry, organ weight, and histopathology for the three generations were examined, respectively. Minor differences were found between the GM group and the RM group or the AIN control group in terms of reproductive data, hematology, blood chemistry parameters, and organ index, but no macroscopic or histological adverse effects were found or considered as treatment-related. In conclusion, the three-generation study of genetically modified maize DBN9936 with Cry1Ab and epsps genes at a high level showed no unintended adverse effects on rats' reproductive system.

N -type silicon is a kind of semiconductor with a narrow band gap that has been reported as an outstanding light-harvesting material for photoelectrochemical (PEC) reactions. Decorating a thin catalyst layer on the n -type silicon surface can provide a direct and effective route toward PEC water oxidation. However, most of catalyst immobilization methods for reported n -type silicon photoanodes have been based on energetically demanding, time-consuming, and high-cost processes. Herein, a high-performance NiFeP alloy ( NiFeP )-decorated n -type micro-pyramid silicon array ( n-Si ) photoanode ( NiFeP/n-Si ) was prepared by a fast and low-cost electroless deposition method for light-driven water oxidation reaction. The saturated photocurrent density of NiFeP/n-Si can reach up to ∼40 mA cm -2 , and a photocurrent density of 15.5 mA cm -2 can be achieved at 1.23 V RHE under light illumination (100 mW cm -2 , AM1.5 filter), which is one of the most promising silicon-based photoanodes to date. The kinetic studies showed that the NiFeP on the silicon photoanodes could significantly decrease the interfacial charge recombination between the n -type silicon surface and electrolyte.

The adsorption of quinoline from wastewater by coking coal (AC-1), HCl-modified coking coal (AC-2), HNO 3 -modified coking coal (AC-3), HF-modified coking coal (AC-4), and H 2 SO 4 -modified coking coals (AC-5) was investigated in this paper. The effects of acid-modified concentration, modification time, and adsorption time versus quinoline removal rate were studied by batch experiments. The quinoline concentration was measured by UV spectrophotometry, the average pore size and specific surface area of coking coal before and after modification were characterized through static nitrogen adsorption, the mineral composition of coking coal was tested by X-ray diffraction, the surface functional groups were tested by Fourier transform infrared spectroscopy, and the surface topography was tested using a scanning electron microscope. The experimental results showed that the adsorption capacity of coking coals was the best when both the modification time was 120 min and the acid-modified concentration was 0.1 mol·L -1 and the quinoline removal rate reaches the highest when the adsorption time was 120 min. The specific surface area of AC-2 increased from 2.898 to 3.637 m 2 ·g -1 , and the removal rate of quinoline increased from 77.64 to 90.61%. Acids reacted with inorganic mineral impurities within coking coal such as hydrogen vanadium phosphate hydrate, which caused an increase in the specific surface area. A new peak appeared in the Fourier transform infrared spectroscopy pattern at the wavenumber 2300 cm -1 . The surface of coking coal modified by acids was rougher than that of AC-1. The adsorption capacity of coking coal was improved after modification, and modified coking coals have the highest potential as low-cost adsorbents for quinoline removal., Competing Interests: The authors declare no competing financial interest., (Copyright © 2019 American Chemical Society.)

Two-dimensional (2D) nonlayered nanomaterials have attracted extensive attention for electronic and optoelectronic applications recently because of their distinct properties. In this work, we first employed a facile one-step method to synthesize 2D nonlayered cadmium sulfide selenide (CdS x Se 1- x , x = 0.33) nanosheets with a highly crystalline structure and then we introduced a generic spin-coating approach to fabricate hybrid nanomaterials composed of PbS quantum dots (QDs) and 2D CdS x Se 1- x nanosheets and demonstrated their potential for high-performance broadband photodetectors. Compared with pure 2D CdS x Se 1- x nanosheet photodetectors, the photoelectric performance of the PbS/CdS x Se 1- x hybrid nanostructure is enhanced by 3 orders of magnitude under near-infrared (NIR) light illumination and maintains its performance in the visible (Vis) range. The photodetector exhibits a broadband response range from Vis to NIR with an ultrahigh light-to-dark current ratio (3.45 × 10 6 ), a high spectral responsivity (1.45 × 10 3 A/W), and high detectivity (1.05 × 10 15 Jones). The proposed QDs/2D nonlayered hybrid nanostructure-based photodetector paves a promising way for next-generation high-performance broadband optoelectronic devices.

This study investigated the composition and proportions of fecal microbiota in Sprague-Dawley rats after consuming two genetically modified (GM) corn lines in comparison with the isogenic corn and the AIN93G standard feed for 10 weeks using bar-coded 16S rRNA gene sequencing. As a result, GM corn did not significantly alter the overall health and alpha-diversity of fecal microbiota. Fecal microbiota structures could be separated into noncorn and corn but not non-GM and GM corn subgroups. Both non-GM and GM corn caused the increase in bacterial populations related to carbohydrates utilization, such as Lactobacillus, Barnesiella, and Bifidobacterium, and the reduction in potentially pathogenic populations, such as Tannerella and Moraxellaceae. In conclusion, similar effects on the fecal microbiota were observed after consuming a GM- and non-GM-corn-based diet for long periods. Further studies are warranted to elucidate the functional relevance of the changes in the proportions of bacterial populations in these diets.

Graphene/metal nanoparticle (NP) composites have attracted great interest for various applications as catalysts, electrodes, sensors, etc., due to their unique structures and extraordinary properties. A facile synthesis of graphene/metal NP composites with good control of size and morphology of metal NPs is critical to the practical applications. A simple method to synthesize graphene/metal NPs under a controllable manner via a self-catalysis reduction at room temperature has been developed in this paper. At first, metal NPs with desirable size and morphology were decorated on GO and then used as catalyst to accelerate the hydrolysis reaction of NaBH4 to reduce the graphene oxide. Compared to the existing methods, the method reported here features several advantages in which graphene/metal NPs are prepared without using toxic and explosive reductant, such as hydrazine or its derivatives, making it environmentally benign, and the reaction can be processed at room temperature with high efficiency and in a large range of pH values. The approach has been demonstrated to successfully synthesize graphene composites with various metal NPs in large quantity, which opens up a novel and simple way to prepare large-scale graphene/metal or graphene/metal oxide composites under mild conditions for practical applications. For example, graphene/AuNP composites synthesized by the method show excellent catalytic capability.

The electrochemical decomposition of persistent perfluorooctanoate (PFOA) with a Ti/SnO2-Sb-Bi electrode was demonstrated in this study. After 2 h electrolysis, over 99% of PFOA (25 mL of 50 mg·L(-1)) was degraded with a first-order kinetic constant of 1.93 h(-1). The intermediate products including short-chain perfluorocarboxyl anions (CF3COO-, C2F5COO-, C3F7COO-, C4F9COO-, C5F11COO-, and C6F13COO-) and F- were detected in the aqueous solution. The electrochemical oxidation mechanism was revealed, that PFOA decomposition first occurred through a direct one electron transfer from the carboxyl group in PFOA to the anode at the potential of 3.37 V (vs saturated calomel electrode, SCE). After that, the PFOA radical was decarboxylated to form perfluoroheptyl radical which allowed a defluorination reaction between perfluoroheptyl radical and hydroxyl radical/O2. Electrospray ionization (ESI) mass spectrum further confirmed that the oxidation of PFOA on the Ti/SnO2-Sb-Bi electrode proceeded from the carboxyl group in PFOA rather than C-C cleavage, and the decomposition processes followed the CF2 unzipping cycle. The electrochemical technique with the Ti/SnO2-Sb-Bi electrode provided a potential method for PFOA degradation in the aqueous solution.

In order to develop a catalyst with high activity for catalytic wet oxidation (CWO) processing at lower temperatures (35 degrees C) and atmospheric pressure, a new CuO-MoO3-P2O5 catalystwas synthesized by a solid-state reaction method and was characterized by X-ray diffraction (XRD), Fourier transformation infrared spectrometer (FTIR), X-ray photoelectron spectroscopy (XPS), selected area electronic diffraction (SAED), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDXS) for elemental mapping. Methylene blue (MB) was adopted to investigate the catalytic activity of CuO-MoO3-P2O5 in CWO processing. The results show that this new catalyst has a high catalytic activity to decolorize MB under mild condition. The color removal of MB (the initial concentration was 0.3 g L(-1) and initial pH was 5) can reach to 99.26% within 10 min at 35 degrees C and atmospheric pressure. Catalyst lifespan and selectivity were also tested, and the results show that after the catalyst was used three times, catalyst activity still remains. Selectivity testing shows that CuO-MoO3-P2O5 has high catalytic activity on degradation of MB, whereas this catalyst has less impact on methyl orange (the color removal was 99.65% for MB and 55% for methyl orange under the same conditions). According to the experimental results, a possible mechanism of catalytic degradation of MB was proposed.