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The rapid industrialization and modern agriculture, increasing emission of heavy metals, and abusing application of pesticide have changed biochemical features of the soil system and water system. Additionally, heavy metals and pesticide compounds may occur together in environments, giving rise to more serious damage to the environment because of their combined toxicity and carcinogenic properties. Therefore, there is a growing need for the development of low-cost adsorbents for their removal. Porous carbon materials have been considered as highly effective materials for pollutant ion control. In this thesis, a novel porous "carbon sponge" is produced using sucrose (S-PCS) with gas-producing molten salt KHCO 3 as the activator at different pyrolysis temperatures under a limited-oxygen condition. Results from these characterizations have indicated that the as-prepared carbon sponges share high surface area (up to 457.6434 m 2  g -1 ) and abundant oxygen-containing functional groups existed on the surface. The essential factors of contact time, initial concentrations, and cyclic availability on adsorption of lead ions and atrazine onto the as-prepared porous samples are also discussed. The typical kinetic and thermodynamic models are carried out to interpret the adsorption behaviors of lead ions and atrazine. The interactive effects and mechanism of lead ions and atrazine adsorption onto S-PCS samples are examined by simultaneous adsorption and preloading adsorption procedures. Combined with the economic and environmental merits of the raw materials, the porous carbon sponges of sucrose by KHCO 3 activated are promising materials for potential practical applications. Graphical abstract The schematic diagram on the preparation of porous carbon sponse from sucrose.

To develop special structure nanomaterials from nature with large specific surface areas and conduct appropriate doping may be effective ways to improve the performance of carbon-basing energy storage devices and mobile power supplies. Pure Gram-positive bacteria carbon material with dense microporous structure and properly self O, N-doping was developed towards highly performance supercapacitors for the first time. The structural characterization and electrochemial survey show that carbon derived from Gram-positive bacteria can bring unexpected material properties for its layered and nitrogen, oxygen containing peptidoglycan cell wall structure. Specifically, bifidobacterium yogurt starter powder as a representative of Gram-positive bacteria was employed and pre-carbonized at 450 °C, then re-carbonized at 700, 800 and 900 °C with KOH activated, respectively. The as-prepared Gram-positive bacteria carbons (GpBCs) have inherited the bacteria's cell wall structure to some extent, which makes the specific surface area as high as 2877 m2/g. When the mess ratio of the precursor to KOH was 1: 2 and re-carbonized at 800 °C, the sample named GpBC-800-2 exhibited a medium specific surface area (2436 m2/g), and possessed proper oxygen(11.20%) and nitrogen(0.56%) doping. For further electrochemial measurement, GpBC-800-2 delivered a specific capacitance of 220 F/g and a 94.5% retention after 10000 cycles in 6 M KOH at the current density of 1 A/g in three-electrode system. For further assessment on symmetry devices, 30 F/g specific capacitance was obtained and 97.8% retention after 10000 cycles were achieved in 6 M KOH at the current density of 1 A/g for symmetry devices. The constructed devices presented an energy density of 4.2 Wh/kg at the power density of 0.5 kW/kg, and still remained 3.19 Wh/kg at the power density of 5 kW/kg. Results of this work have given a first glance for pure Garm-positive bacteria carbon materials in supercapacitor application. [ABSTRACT FROM AUTHOR]

Heteroatom doped carbon dots have great potential in sensing field because of their good optical properties, high selectivity and sensitivity to targets. Herein, sulfur and nitrogen co-doped carbon dots (SNCDs) was synthesized by one-step hydrothermal reaction of κ-carrageenan and glutathione. The surface of the prepared SNCDs was modified by active groups, which not only enhance the optical properties, but also improve the analytical detection performance. Then, SNCDs, as a high-efficient "on-off-on" fluorescent sensor, was fabricated for sequence determination of Ag+ and Lime Sulfur (LS). Furthermore, it performed good selectivity and sensitivity to Ag+ and LS even with the interference of other metal ions or pesticides. The linear detection range of Ag+ and LS by SNCDs was 0–100 µM and 0–1 mg/L, and the detection limit was 0.124 µM and 50 µg/L, respectively. More importantly, it has been successfully used in the detection of actual water samples with recovery rates of 98.6~107.1%. In addition, a portable, reusable and highly absorbent fluorescent resin ball was constructed to enrich the application of SNCDs. [Display omitted] • S, N co-doped carbon dot (SNCDs) was synthesized by κ-carrageenan and glutathione in one step. • The prepared SNCDs can be applied for the sequential detection of Ag+ and Lime Sulfur. • Fluorescent resin balls were prepared for further application [ABSTRACT FROM AUTHOR]

Green, blue and pink fluorescent carbon dots (o/m/p-CDs) were prepared by one-step hydrothermal method with three isomers (o/m/p) of phenylenediamine as nitrogen and carbon sources and ethanol as solvent. The obtained carbon dots exhibited different luminescence behaviors, and the luminescence behaviors were affected by solvent and pH. More interestingly, m-CDs exhibited obvious discoloration behavior under different pH conditions and had excellent linear relationship under acidic and basic conditions, respectively. Furthermore, we combined m-CDs with test paper, PVA film, and cotton fabric, respectively, to prepare composites for visual pH detection. The as-prepared composite material has excellent visual detection effect for a small amount of test sample (<5 μL) in the fine pH range (0.5 unit), and could be applied to trace pH detection. [Display omitted] • Green, red and blue fluorescent CDs were prepared via hydrothermal method with ethanol and o/m/p-phenylenediamine. • Mechanisms of lyochromic and pH-induced discoloration were explored. • The o/m/p-CDs were combined with test strips, PVA films and cotton fabrics for fine pH (0.5 units) detection. [ABSTRACT FROM AUTHOR]

Abstract: Diamond-like carbon coating (DLC) was deposited on AZ31 magnesium alloy by ion beam deposition technique in this study. A columnar Cr layer with a (110) preferred texture and a columnar CrN layer with a (111) preferred texture were applied as interlayers in the DLC coating/AZ31 substrate systems. The addition of these interlayers improved the adhesion between coating and substrate effectively, but did not enhance the corrosion resistance of the DLC/AZ31 systems due to the formation of galvanic cell between substrate and interlayer in the region of through-thickness defects in 3.5wt.% NaCl solution. In addition, the effect of bias voltage on the corrosion resistance of CrN/Cr coatings on magnesium alloys was investigated. Although the application of bias voltage induced the coating denser, it was still difficult for CrN/Cr coating to reduce the corrosion current density of AZ31 due to the large difference between coating and substrate in galvanic series. [Copyright &y& Elsevier]

This research examines the effects of various factors on farmer participation in agricultural tree plantations for economic, environmental, social, and carbon-uptake purposes, and potential costs of sequestering carbon through afforestation in western Canada. Using data from a survey of landowners, a discrete choice random utility model is used to determine the probability of landowners' participation in and corresponding mean willingness to accept (WTA) compensation for a tree-planting program. WTA includes positive and negative benefits to landowners from planting trees, benefits not captured by foregone returns from agricultural activities on marginal land. Estimates of WTA are less than foregone returns, but even so average costs of creating carbon credits still exceed their projected value under a CO2-emissions trading scheme. La présente étude a examiné les effets de divers facteurs sur la participation des producteurs agricoles à la plantation d'arbres à des fins économiques, environnementales, sociales et d'absorption du gaz carbonique, ainsi que les coûts potentiels de la séquestration du carbone au moyen du boisement dans l'Ouest canadien. À l'aide des données d'un sondage effectué auprès de propriétaires fonciers, nous avons utilisé un modèle d'utilité aléatoire à choix discrets pour déterminer la probabilité de participation des propriétaires fonciers à un programme de boisement et leur consentement à recevoir (CAR) une compensation financière pour leur participation. Le CAR inclut les avantages favorables et défavorables que le boisement procure aux propriétaires fonciers, des avantages non saisis par les revenus sacrifiés des activités agricoles sur des terres marginales. Les estimations du CAR sont inférieures aux revenus sacrifiés, mais malgré tout, les coûts moyens de la mise en uvre de programme de crédits pour le carbone demeurent supérieurs à leur valeur prévue dans un scénario d'échange de droits d'émission de CO2. [ABSTRACT FROM AUTHOR]

China has committed to ambitious targets to reduce its carbon emissions in the next decades, in order to combat climate change and improve the environment. The realization of the targets depends on the fair and effective mitigation plans of all provinces. However, with varying ecological and environmental conditions and social-economic development, it is a critical issue to quantify the provinces' efforts equally. This paper proposed a comprehensive fE index in coordinating ecology, equity and economy, by accounting for carbon emissions and sinks to characterize provincial carbon emission status in China, from 2000 to 2017, which shows a spatial pattern of "boundary high, central low". The provinces with higher fE value (>1.5) in boundary areas can be seen as "relative equality" provinces with good ecology circulation, equity and economic efficiency. The provinces with lower fE value (<0.7) in central areas around Bohai Bay are regarded as "severe inequality" provinces, and are identified as the hot-spot provinces, which have emitted more CO2 than their equity share by occupying the carbon emission space of other provinces in recent decades. These results could provide a reference for a provincial guide for carbon reduction and sustainable development of the low-carbon economy. [ABSTRACT FROM AUTHOR]

Abstract: The functional group p-benzensulfonic acid (pb-SO3H) was chemically attached to the surfaces of two different carbon supports, XC72 and BP2000, to improve carbon support corrosion resistance. An accelerated durability test (ADT) utilizing a rotating disk electrode (RDE) system was used to study the corrosion of Pt catalysts using these two carbon supports, Pt/FXC72-SO3H and Pt/FBP2000-SO3H, under simulated fuel cell conditions. The results showed that the functional group pb-SO3H can effectively reduce the performance decay of these catalysts by enhancing the corrosion resistance of the carbon support and promoting the stability of the Pt nanoparticles. The ECASA and ORR current measurements of these catalysts indicate that the effects of the functional group (pb-SO3H) on improving carbon corrosion resistance were more significant for the BP2000 than for the XC72. TME imaging revealed that the size of the Pt nanoparticles was significantly reduced and the particle distribution was improved in a polymer electrolyte fuel cell (PEFC). [Copyright &y& Elsevier]

The electronic, magnetic and optical properties of C- and N-doped CeO 2 bulk and (111) surface have been systematically investigated by first-principles calculations. The results show that the spin splitting occurs when doping atoms replace the anion sites in the CeO 2 matrix, causing a local magnetic moment of 2.00, and 1.00 μ B for C- and N-doping, respectively. The strong hybridization between dopants 2 p and O 2 p triplet-states around the Fermi level gives rise to the half-metallic character for doped bulk systems, while substitution onto the surface eliminates the degeneration of dopants 2 p orbitals, which results in anisotropic spin atmosphere. Especially, owing to the low formation energy and available RTFM, N-doped CeO 2 would be easily realized in the experiment and should also be wonderful candidate materials for oxide spintronics. In addition, compared with N-doped CeO 2 , the calculated optical properties reveal that C-doped CeO 2 (111) surface is able to enhance the absorption of the visible light. [ABSTRACT FROM AUTHOR]

• The DA electrochemical sensor was fabricated by overall hierarchical porous carbon. • Sensor can be regenerated with ultrasonic cleaning by removing DA pollutants. • Sensor showed wide linear range and low detection limit to DA. The detection of dopamine (DA) based on electrochemical sensor is of great importance to human diseases diagnosis and treatment. However, such sensors usually faced with the performance deterioration due to serious dopamine fouling. Herein, we fabricated a three-dimensional (3D) porous carbon sheet with hierarchical ordered mesopores by a facile dual-template method, the integrated electrochemical sensor was further discussed in terms of the evolution of porous structure. Results showed that the hierarchical porous structure would provide more mass transport channels and larger active area, resulting in higher sensitivity. In particular, the 3D framework could withstand strong ultrasound cleaning and maintained the superior electrochemical properties with high repeatability after the ultrasonic cleaning for dopamine fouling. The integrated sensor based on 3D porous carbon with high sp2 content presented the excellent performance toward DA detection with wide linear range from 800 nM to 400 μM, low detection limit of 100 nM as well as good selectivity to routine interference substances. It can be said that the constructed 3D hierarchical mesoporous carbon provides the great potential to be a promising material for DA electrochemical sensing platform construction. Image, graphical abstract [ABSTRACT FROM AUTHOR]