摘要：
With the development of the removal of organic pollutants in the soil and water environment, antibiotics have been considered as emerging pollutants and received considerable attention among the scientific community. Thus, there is a need for an effective, economical, fast, operational feasible and environmental-friendly technology to remove antibiotics. Adsorption technology would be one of the most promising option on the basis that it best meets the criteria we set out above. From the most primitive activated carbon to the most innovative modified biochar, carbon-based materials have played a significant role in the adsorption process of antibiotics all the time. This paper reviews the adsorption behavior of some representative antibiotics (e.g., chloramphenicols, sulfonamides, tetracyclines, flouroquinolones) over various carbonaceous materials (i.e., activated carbon, carbon nanotubes, graphene, and biochar). Nevertheless, in addition to the structural characteristics and adsorption capacities of carbon-based materials, a special emphasis was placed on the underlying adsorption mechanisms and roles of different influencing factors in the adsorption process. Moreover, the knowledge gaps and research challenges have been highlighted, including design and optimization of the carbonaceous materials for antibiotics adsorption.
摘要：
Iron nanoparticles encapsulated within boron and nitrogen co-doped carbon nanoshell (B/N-C@Fe) were synthesized through a novel and green pyrolysis process using melamine, boric acid, and ferric nitrate as the precursors. The surface morphology, structure, and composition of the B/N-C@Fe materials were thoroughly investigated. The materials were employed as novel catalysts for the activation of potassium monopersulfate triple salt (PMS) for the degradation of levofloxacin (LFX). Linear sweep voltammograms and quenching experiments were used to identify the mechanisms of PMS activation and LFX oxidation by B/N-C@Fe, where SO4− as well as HO were proved to be the main radicals for the reaction processes. This study also discussed how the fluvic acid and inorganic anions in the aqueous solutions affected the degradation of LFX and use this method to simulate the degradation in the real wastewater. The synthesized materials showed a high efficiency (85.5% of LFX was degraded), outstanding stability, and excellent reusability (77.7% of LFX was degraded in the 5th run) in the Fenton-like reaction of LFX. In view of these advantages, B/N-C@Fe have great potentials as novel strategic materials for environmental catalysis.
摘要：
The charge separation and transfer are critical steps during the photoelectrochemical processes. In this paper, we focus on the interfacial properties within the heteropolyacid (denoted as PW12) modified WO3 heterojunction film synthesized by an epitaxial growth method. The characterizations show that heteropolyacid is formed on the surface of WO3 plates with less interfacial defects between PW12 and WO3. The PW12/WO3 photoanodes synthesized via the in-situ method display a photocurrent density of 0.65 mA/cm(2) at 1.23 V vs. RHE, which exhibits 1.6 times as much as the bare WO3. And the composite achieves the maximum value of 1.52 mA/cm(2) at 1.8 V vs. RHE, while those of PW12/WO3 films prepared by a dip-coating method and pristine WO3 films are just 1.10 and 0.85mA/cm(2). The improvements in PEC performances of PW12/WO3 photoanodes (in-situ) were attributed to the higher electron transmission rate and longer electron lifetime resulted from the less interfacial defects. Moreover, the PW12/WO3 film was treated with TiCl4 solution to form a TiO2/PW12/WO3 ternary heterojunction, which exhibits a higher photocurrent density of 1.89 mA/cm(2). The current research has proposed a new perspective and method for the design of highly efficient heterojunction photoelectrodes and inorganic synthesis. (c) 2019 Elsevier Ltd. All rights reserved.
摘要：
Biochar-based fertilizers have attracted increased attention, because biochar can improve the soil fertility, promote plant growth and crop yield. However, biochar-based controlled release nitrogen fertilizers (BCRNFs) still face problems because of the high cost, inefficient production technology, instability of nitrides, and the challenge associated with the controlled release of nutrients. In this study, we hydrothermally synthesised novel BCRNFs using urea-loaded biochar, bentonite and polyvinyl alcohol for controlled release of nutrients. Scanning electron microscopy and gas adsorption were conducted to identify the urea-loading and storage of bentonite in the inner pores of the biochar particles. X-ray diffraction, Fourier transform infrared spectroscopic and X-ray photoelectron spectroscopic studies demonstrated that strengthening the interactions among biochar, urea, and bentonite, helps control the moisture diffusion and penetration of bentonite, thereby leading to nutrient retention. The BCRNF showed significantly improved nutrient release characteristic compared with that of a mixture of biochar and urea. This urea-bentonite composite loaded with urea provides control over the release of nutrients stored in the biochar. BCRNF, especially those produced hydrothermally, can have potential applications in sustainable food security and green agriculture.
关键词：
Advanced oxidation processes;Biochar-supported;Density functional theory;Nanoscale zero-valent iron
摘要：
Ciprofloxacin has been frequently detected in water environment, and its removal has become a significant public concern. Biochar-supported nanoscale zero-valent iron (BC/nZVI) to activate hydrogen peroxide (H2O2) has many advantages on promoting the removal of organic contaminants. In this paper, the BC/nZVI activating H2O2 degradation of ciprofloxacin was systematically investigated by experimental and theoretical approaches. The morphologies and property analysis showed that nZVI particles distributed uniformly on the biochar surface, which mainly include (-)OH, >CO and COC and CO groups. Different reaction conditions were compared to define the optimal conditions for ciprofloxacin removal in BC/nZVI/H2O2 system. More than 70% of ciprofloxacin was removed in the optimal conditions: acidic condition (pH 3 approximately 4), low doses of H2O2 (20 mM), and temperature of 298 K. The hydroxyl radical ((*)OH) oxidation was the primary pathway in BC/nZVI/H2O2 degradation of ciprofloxacin process. The theoretical calculation indicated that hydrogen atom abstraction (HAA) pathways were the dominant oxidation pathways contributing 92.3% in overall secondorder rate constants (k) of (*)OH and ciprofloxacin. The current results are valuable to evaluate the application of BC/nZVI activating H2O2 degradation of ciprofloxacin and other fluoroquinolone antibiotics in water treatment plants.
摘要：
A hybrid host combined with rigid and flexible structural moieties to confine sulfur species physically and chemically is designed and applied for the lithium-sulfur battery. The self-assembled graphene aerogel with nano-MnO2 modified walls serves as the rigid sulfur container while the cross-linked PVP-PVA interpenetrating network acts as the flexible polysulfide trap. The synergic actions enable the hybrid host to present not only good electronic and ionic 3D transfer pathways, but also superior physical and chemical sulfur confinement. Consequently, the MGPP@S composite cathode exhibits excellent electrochemical energy storage performance. It shows initial discharge capacity of 1492, 1054, 833, 659 mAh g(-1) at 0.1C, 0.2C, 0.5C, 1C, respectively; meantime it retains a capacity over 755 mAh g(-1) during 250 cycles at 0.2C and only has 0.06% capacity decay per cycle during 500 cycles at 1C. The major capacity decay on first several cycling is accounted for sulfurous consumption in saturating the electrolyte and building the interfacial layer; afterwards, the composite electrode can perform consistent capability upon extending cycling. (C) 2019 Elsevier B.V. All rights reserved.
期刊：
International Journal of Hydrogen Energy,2019年44(2):594-604 ISSN：0360-3199
通讯作者：
Li, Jie;Li, Wenzhang
作者机构：
[Qiu, Xiaoqing; Yin, Xiang; Li, Jie; Liu, Qiong; Wang, Keke; Liu, Yang; Li, Wenzhang] Cent South Univ, Sch Chem & Chem Engn, Changsha 410083, Hunan, Peoples R China.;[Li, Wenzhang] Cent South Univ, Hunan Prov Key Lab Efficient & Clean Utilizat Man, Changsha 410083, Hunan, Peoples R China.;[Li, Yaomin] UCL, Dept Chem, 20 Gordon St, London WC1H 0AJ, England.;[Liu, Yang] Hunan Agr Univ, Coll Resources & Environm, Changsha 410128, Hunan, Peoples R China.;[Li, Dongwei] Chongqing Univ Educ, Div Sci Res Management, Chongqing 400065, Peoples R China.
通讯机构：
[Li, Jie; Li, Wenzhang] C;Cent South Univ, Sch Chem & Chem Engn, Changsha 410083, Hunan, Peoples R China.;Cent South Univ, Hunan Prov Key Lab Efficient & Clean Utilizat Man, Changsha 410083, Hunan, Peoples R China.
关键词：
Cu 2 O–BiVO 4;PEC tandem cell;Self-driven water splitting;Solar hydrogen
摘要：
An integrated solar water splitting tandem cell without external bias was designed using a FeOOH modified TiO2/BiVO4 photoanode as a photoanode and p-Cu2O as a photo-cathode in this study. An apparent photocurrent (0.37 mA/cm(2) at operating voltage of +0.36 V-RHE) for the tandem cell without applied bias was measured, which is corresponding to a photoconversion efficiency of 0.46%. Besides, the photocurrent of FeOOH modified TiO2/BiVO4 Cu2O is much higher than the operating point given by pure BiVO4 and Cu2O photocathode (-0.07 mA/cm(2) at +0.42 VRHE). Then we established a FeOOH modified TiO2/BiVO4 Cu2O two-electrode system and measured the current density voltage curves under AM 1.5G illumination. The unassisted photocurrent density is 0.12 mA/cm(2) and the corresponding amounts of hydrogen and oxygen evolved by the tandem PEC cell without bias are 2.36 umol/cm(2) and 1.09 urnol/cm(2) after testing for 2.5 h. The photoelectrochemical (PEC) properties of the FeOOH modified TiO2/BiVO4 photoanode were further studied to demonstrate the electrons transport process of solar water splitting. This aspect provides a fundamental challenge to establish an unbiased and stabilized photoelectrochemical (PEC) solar water splitting tandem cell with higher solar to -hydrogen efficiency. (C) 2018 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.
