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The persistence of pharmaceutical and personal care products (PPCPs) such as norfloxacin (NFX) poses a serious threat to the water environment, and the development of efficient and cost-effective advanced oxidation catalysts is an important step toward resolving this issue. Herein, Fe and N co-doped graphene (FeNGO) was synthesized from graphene oxide (GO), urea, and iron salt via simple impregnation pyrolysis, and applied for activating peroxymonosulfate (PMS) to degrade NFX. FeNGO possessed a two-dimensional porous sheet structure and was rich in defects, nitrogen species, and active sites. Compared with the control catalyst doped with N or Fe alone, FeNGO/PMS system showed the best degradation performance with 97.7% removal of NFX after 30 min, the rate constant was 7.1 and 1.7 times than that for NGO and FeGO, respectively. Fe 3 N was the main active site of FeNGO, and it is confirmed that singlet oxygen (1O 2) and superoxide radical (O 2 •-) were the primary oxidation active species (ROS) during NFX degradation. The formation of 1O 2 came from the transformation of O 2 •- and PMS decomposition. FeNGO showed strong pH adaptability, and also exhibited stale degradation performance in saliferous water matrices. It is believed that this work will offer theoretical and practical guidance for PMS activation by non-radical pathways. [Display omitted] • The FeNGO was prepared and the Fe 3 N were the main active sites. • The FeNGO exhibited good pH flexibility and had low Fe leaching. • O 2.•- and 1O 2 were primary cause of norfloxacin degradation. • Possible degradation pathway of norfloxacin was proposed. [ABSTRACT FROM AUTHOR]

[Display omitted] • A simple metal–organic framework-derivatised strategy was adopted to prepare Cu/Cu2O@NG materials. • Cu/Cu2O@NG-2 showed a good catalytic performance with a FE of 56 % and a current density of 19.0 mA/cm2 for C2–C3 products. • NG facilitated the dispersion of Cu/Cu2O particles, increased the catalytic active sites and enhance the stability. CO 2 is the main gas that causes the greenhouse effect, so electrochemical reduction of CO 2 can be regarded as a solution to alleviate the climate crisis. In this study, a simple metal–organic frameworks (MOFs)-derivatized strategy was adopted to prepare electrocatalyst, where MOF-199 and N-doped graphene (NG), as precursors, were electroreduced to obtain Cu/Cu 2 O@N-doped graphene (Cu/Cu 2 O@NG) materials for efficient CO 2 electroreduction to produce C 2 -C 3 products (ethylene, ethanol and n-propanol). A series of Cu/Cu 2 O@NG materials, especially Cu/Cu 2 O@NG-2 with a Faraday efficiency of 56 % and corresponding current density of 19.0 mA/cm2 for C 2 -C 3 products, showed a considerably better catalytic performance compared with the MOF-199-derived Cu/Cu 2 O material. This good performance was mainly attributed to the synergistic effect between the evenly dispersed Cu/Cu 2 O and NG, leading to good CO 2 adsorption capacity, rapid mass transfer and abundant active sites. [ABSTRACT FROM AUTHOR]

Adsorption and advanced oxidation technology are important means to remove organic pollutants, and the combination of adsorption and catalytic degradation to construct a multi-field coupled system can realize valid adsorption and degradation of organic contaminants. In this paper, CuBi 2 O 4 supported by a nonmetallic element-modified graphene hydrogel composite structure CuBi 2 O 4 /X-rGH (X = N, P, S, B) was synthesized and applied to the efficient removal of organic pollutants. We found that the doping of nonmetallic elements enhances the graphene conjugated large π-bond system, which not only improves the adsorption performance of pollutants but also increases the graphene conductivity and builds more carrier transport channels, which is beneficial to the photocatalytic Fenton synergistic degradation activity. Among them, CuBi 2 O 4 /P-rGH could achieve 90 % degradation of phenol (50 ppm) after 20 min of turning on the light, which was nearly 2 times more than the degradation activity of CuBi 2 O 4 /rGH. Electron paramagnetic resonance (EPR) and quenching experiments proved that ·OH was the main active species in the synergistic degradation process, and the mechanism of adsorption of nonmetallic modified graphene hydrogel hybrid catalysts and in situ photocatalytic Fenton degradation of pollutants was proposed. [ABSTRACT FROM AUTHOR]

In this study, nickel tailings were utilized to prepare electrothermal coatings composited with nano-graphite/multilayer graphene, and the effects of heat treatment temperature and time of nickel tailings on the performance of electrothermal coatings were investigated. The experimental results show that the addition of nickel tailings can significantly enhance the performance of the composite electrothermal coatings. Using nickel tailings treated at 60 °C for 2 h caused the temperature response time of the coatings to decrease by 57%, and the maximum temperature was 55.4 °C. However, as the treatment temperature was increased to 100 °C, a large amount of oxygen was introduced into the system, which led to a weakening of the ferric ion conduction in the ferromagnesian olivine, resulting in only a 28.6% reduction in the temperature response time at the maximum temperature of 45.4 °C. Meanwhile, it was established that the multidimensional stabilized conductive network formed by nickel tailings and nano-graphite/multilayer graphene enhanced the comprehensive performance of the coating. In addition, the study on the coating work stability revealed that the electrothermal coating prepared by adding nickel tailings treated at 60 °C for 2 h can maintain the maximum stable temperature above 55 °C for a long period of time, which is significantly better than the samples without nickel tailings and with nickel tailings heat-treated at 100 °C. This electrothermal composite coating is particularly suitable for low-pressure and low-power high-efficiency heating equipment, energy saving and environmental protection. Compared with the existing work, this experiment uses nickel tailings solid waste as auxiliary filler, which has the advantages of low cost, simple fabrication process, energy saving, environmental protection, low energy consumption, etc. It provides a more sustainable and eco-friendly solution for heating needs in a variety of fields. The material will be developed in the direction of higher conversion efficiency and higher temperature threshold in the future. It can be widely used in the fields of intelligent heating of houses, intelligent electric heating of clothes, and de-icing of wings of aircrafts. • Incorporation of waste nickel tailings into nano-graphite/multilayer graphene composite powders to improve the performance of composite electrothermal coatings. • Temperature response time of the electrothermal coating by 57%. • The fluctuation of each performance in the cycling stability test lasting 10 days was less than 1%. [ABSTRACT FROM AUTHOR]

• Novel graphene-like nanosheets stacked carbon nanotube structure was synthesized for the first time. • It was found for the first time that hydrogen peroxide has not only reducing property but also decomposing and stripping function. • Lamellar carbon nanotubes are bonded to transition metal alloys. • Large specific surface area plays a greater positive role in product transport and electron transport. • The novel structural catalyst is highly active in HER and OER. In this study, we prepared a novel graphene-like stacked carbon nanotube-supported Fe-Ni alloy nanometer composite material. The cubic structure of nickel dimethylglyoxime was synthesized as the base material. Under hydrothermal condition, FePc was adsorbed on the surface of the nickel dimethylglyoxime cube. In addition, hydrogen peroxide not only decomposes FePc into Pc and Fe2+, but also reduces Fe2+ to Fe. On the other hand, hydrogen peroxide was first found could decompose and peel the cube of nickel dimethylglyoxime into a novel type of nanotubes with graphene-like nanosheet stacking structure. After the final calcination, the Fe2+ and Ni2+ were converted to FeNi alloy, and the dimethylglyoxime carrier with its loaded Pc was converted to carbon material. The novel structure has a large BET, which is conducive to electron transport, product transport and provides a large active site for Fe-Ni3 alloy. The composite has high electro-catalysis performance for OER and ORR, which provides a new idea for the study of new energy reserves, energy conversion and reserve materials. This study provides a new idea for preparing novel carbon nanotube-loaded transition metal composites in the field of electrocatalysis. The reducing and weak oxidizing decomposition of hydrogen peroxide was first found could peel off the dimethylglyoxime cube to a new graphene-like nanolayer stacking structure carbon nanotube structure. The prepared materials have high electrocatalytic activity for oxygen evolution and oxygen reduction reactions. [Display omitted] [ABSTRACT FROM AUTHOR]

Graphene oxide (GO) is one of the promising two-dimensional nanomaterials for the development of fluorescent aptasensors. Its limitations are related to the inevitable negative effect of GO on the fluorescence. Here this challenge was explored and solved by ssDNA adsorption on GO and centrifugal separation of GO from the ensembled solution. On this basis, a fluorescent aptasensor was constructed for the detection of staphylococcal enterotoxin A (SEA), in which GO assisted the separation of free aptamers to achieve cDNA-induced structure-switching from SEA/aptamer complex to dsDNA, and GO was added again to separate free cDNA and reduce the background signal. SYBR Green I was inserted into dsDNA as the fluorescent signal to achieve the quantitative analysis. It displayed a wide linear range (1–8000 ng/mL), low detection limit (0.899 ng/mL), and satisfactory application in milk and milk powder. Notably, the method was low-cost, general, and instructive for other two-dimensional nanomaterials. [Display omitted] • A label-free, low-background fluorescent aptasensor for staphylococcal enterotoxin A. • Graphene oxide-assisted ssDNA separation to reduce the background and interference. • The cDNA-induced structure-switching formed dsDNA and amplified the signal. • The method was low-cost, general, and instructive for two-dimensional nanomaterials. [ABSTRACT FROM AUTHOR]

• Graphene aerogel prepared at different freeze-casting temperatures yield unequal electromagnetic properties. • Modulate absorption/reflection shielding performance through the introduction of new skeleton. • Graphene aerogel with different pore structures reveal different mechanical properties. We report a comprehensive analysis of the Electromagnetic (EM) properties of graphene aerogel-based shielding materials prepared by freeze casting. Controlling the freeze casting temperature allows for tailoring the pore sizes of graphene aerogels, which further affects the permittivity and EM shielding properties. To protect the aerogel structures from collapsing during high temperature heat-treatment, we used Melamine sponge (MS) as a supporting strut. Through a comparison with bare aerogels, we find that the presence of MS can significantly modify both the reflection and absorption performances and that an absorption-dominated shielding material can be obtained. After heat-treatment at 1000 °C for two hours, the MS-supported aerogel sample (MS-aero) showed a shielding efficiency of 55.8 dB. Our work shows that the material composition and the microstructural architecture of aerogels crucially influence their electromagnetic shielding efficiency. [ABSTRACT FROM AUTHOR]