NEW JOURNAL OF CHEMISTRY
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2021
·Vol. 45
·期 28
·12669-12677
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IF 3.591
Yu Jiang,Chen Yang,Qian Yao,Yurong Deng,Jingjing Yang,Yanjun Liu,Zhuozhi Ouyang,Weilin Huang,Zhi Dang
To clarify the function of the nitrogen-containing structures on the adsorption of heavy metals, nitrogen-enriched biochars (NBCs) mainly composed of pyrrolic, pyridinic, and graphitic nitrogen were prepared to investigate the interaction mechanism with Cd(II). The results of batch experiments revealed that the saturated Cd(II) adsorption capacities of Pr-NBC, Pd-NBC, and Gp-NBC were 12.68, 24.04, and 35.95 mg g−1 respectively. The strongest adsorption ability was found for the Gp-NBC and was ascribed to the enhancement of graphitic nitrogen. The results from SEM-EDS and XRD, and the zeta potentials for the materials revealed that carbonate precipitation, cation exchange, and electrostatic interactions contributed to the adsorption of Cd(II). XPS and FTIR demonstrated that nitrogen in the carbon framework might have promoted the adsorption by forming cation–π interactions between graphitic nitrogen and Cd(II). The electrostatic potential distribution of the nitrogen with different configurations fully confirmed this. The theoretical calculations also proved that graphitic nitrogen had the lowest interaction energy to Cd(II), which further verified the strong contribution of graphitic nitrogen to the adsorption of heavy metal. Nitrogen-enriched biochar effectively adsorbs, changes the migration process of heavy metals in the natural environment, and thus alleviates the current situation of heavy metal pollution.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Nature Communications
·
2020
·Vol. 11
·期 1
·1-10
·
IF 12.121
Tian Kesong,Wang Junyan,Cao Ling,Yang Wei,Guo Wanchun,Liu Shuhu,Li Wei,Wang Fengyan,Li Xueai,Xu Zhaopeng,Wang Zhenbo,Wang Haiyan,Hou Yanglong
Integrating nitrogen species into sp 2 -hybridized carbon materials has proved an efficient means to improve their electrochemical performance. Nevertheless, an inevitable mixture of nitrogen species in carbon materials, due to the uncontrolled conversion among different nitrogen configurations involved in synthesizing nitrogen-doped carbon materials, largely retards the precise identification of electrochemically active nitrogen configurations for specific reactions. Here, we report the preparation of single pyrrolic N-doped carbon materials (SPNCMs) with a tunable nitrogen content from 0 to 4.22 at.% based on a strategy of low-temperature dehalogenation-induced and subsequent alkaline-activated pyrolysis of 3-halogenated phenol-3-aminophenol-formaldehyde (X-APF) co-condensed resins. Additionally, considering that the pseudocapacitance of SPNCMs is positively dependent on the pyrrolic nitrogen content, it could be inferred that pyrrolic nitrogen species are highly active pseudocapacitive sites for nitrogen-doped carbon materials. This work gives an ideal model for understanding the contribution of pyrrolic nitrogen species in N-doped carbon materials.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF POWER SOURCES
·
2024
·
IF 8.1
Yangkai Sun,Zijian He,Huiyang Fan,Shurong Wang
Carbon nanosheets with layer-stacked porous structures and surface functionalized groups are beneficial for efficient ion storage in supercapacitor electrode materials, but achieving high cost-effectiveness and controllable surface groups remains a significant challenge. Herein, the biomass-derived chitosan and sodium alginate are selected as raw materials for self-assembly reaction with phytic acid as a cross-linking agent. The protonated chitosan and sodium alginate form a cross-linked network structure through hydrogen bonding and electrostatic adsorption, which is subsequently carbonized and activated to synthesize porous graphitic carbon nanosheets (PNPCN-X). PNPCN-X realizes an efficient distribution of porous and graphitic structures. It's noteworthy that phytic acid facilitates the fixation of N atoms, and various N configurations can be adjusted by altering the content of phytic acid. Optimized PNPCN-1.5 exhibits a high content of structurally stable pyridinic-N and graphitic-N configurations, which are confirmed to serve as active sites substantially augmenting the ion adsorption capacity through Density Functional Theory (DFT) calculations. Benefiting from its exceptional physicochemical properties, PNPCN-1.5 achieves 322 F g −1 as electrode materials in the three-electrode system, while the symmetrical supercapacitor assembled with EMIMBF 4 electrolyte attains 56.29 W h kg −1 . Furthermore, various kinetic analyses extensively elucidate its capacitance distribution characteristics and ion diffusion rates.
研究领域:
材料科学
·
能源存储
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE ENERGY INSTITUTE
·
2023
·
IF 5.7
Shanjian Liu,Wenjing Zhao,Zhisen He,Mengqian Yin,Jingang Yao,Weiming Yi
Different volume ratios of carbon dioxide and nitrogen were mixed into the nitrogen-rich pyrolysis of cellulose , resulting in the production of nitrogen-doped biochar and nitrogen-containing bio-oil. When the urea mixture ratio was greater than 50%, the added CO 2 promoted the production of nitrogen-containing bio-oil, reaching a maximum of 26.03% ( M = 50%) at 10 vol% CO 2 + 90 vol% N 2 . Pyridine , pyrrole , and amines were the main nitrogen-containing compounds produced when using atmospheres of pure nitrogen and carbon dioxide. Upon increasing the volume ratio of CO 2 , the nitrile content increased significantly, becoming one of the main nitrogen-containing compounds. In addition, due to chemical stability, the thermal conversion of CO 2 demands a significant input of energy, so the required activation energy also increased. Adding CO 2 to simulate high-temperature anoxic flue gas is a promising method for biomass pyrolysis to obtain nitrogen containing chemicals with high added value and high nitrogen doped Biochar.
研究领域:
化学工程
·
环境科学
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）