Journal of Environmental Sciences
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2022
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IF 6.796
Chenxiao Qi,Haixiang Chen,Xiufang Chen,Chengyu Chu,Xueting Mei,Wangyang Lu,Nan Li
Graphite carbon nitride has many excellent properties as a two-dimensional semiconductor material so that it has a wide application prospect in the field of photocatalysis . However, the traditional problems such as high recombination rate of photogenerated carriers limit its application. In this work, we introduce nitrogen deficiency into g-C 3 N 4 to solve this problem a simple and safe in-situ reduction method. g-C 3 N 4 /CaCO 3 was obtained by a simple and safe one-step calcination method with industrial-grade micron particles CaCO 3 . Cyano group modification was in-situ reduced during the thermal polymerization process, which would change the internal electronic structure of g-C 3 N 4 . The successful combination of g-C 3 N 4 and CaCO 3 and the introduction of cyanide have been proved by Fourier transform infrared spectroscopy and X-ray photoelectron spectrometer. The formation of the cyano group, an electron-absorbing group, promotes the effective separation of photogenic electron hole pairs and inhibits the recombination of photogenic carriers. These advantages result in the generation of more •O 2 − and 1 O 2 in the catalytic system, which increases the photocatalytic efficiency of nicotine degradation by ten times. Furthermore, the degradation process of nicotine has been studied in this work to provide a basis for the degradation of nicotine organic pollutants in the air.
研究领域:
材料科学
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环境科学
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化学
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DOI
PubMed
高影响因子
CHINESE JOURNAL OF CATALYSIS
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2021
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IF 8.271
Fang Li,Xiaoyang Yue,Haiping Zhou,Jiajie Fan,Quanjun Xiang
The active site amount of photocatalysts, being the key factors in photocatalytic reactions, directly affects the photocatalytic performance of the photocatalyst. Pristine graphitic carbon nitride (g-C 3 N 4 ) exhibits moderate photocatalytic activity due to insufficient active sites. In this study, cyano-modified porous g-C 3 N 4 nanosheets (MCN-0.5) were synthesized through molecular self-assembly and alkali-assisted strategies. The cyano group acted as the active site of the photocatalytic reaction, because the good electron-withdrawing property of the cyano group promoted carrier separation. Benefiting from the effect of the active sites, MCN-0.5 exhibited significantly enhanced photocatalytic activity for CO 2 reduction under visible light irradiation. Notably, the photocatalytic activity of MCN-0.5 was significantly reduced when the cyano groups were removed by hydrochloric acid (HCl) treatment, further verifying the role of cyano groups as active sites. The photoreduction of Pt nanoparticles provided an intuitive indication that the introduction of cyano groups provided more active sites for the photocatalytic reaction. Furthermore, the controlled experiments showed that g-C 3 N 4 grafted with cyano groups using melamine as the precursor exhibited enhanced photocatalytic activity, which proved the versatility of the strategy for enhancing the activity of g-C 3 N 4 via cyano group modification. In situ diffuse reflectance infrared Fourier transform spectroscopy and theoretical calculations were used to investigate the mechanism of enhanced photocatalytic activity for CO 2 reduction by cyano-modified g-C 3 N 4 . This work provides a promising route for promoting efficient solar energy conversion by designing active sites in photocatalysts.
研究领域:
材料科学
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环境科学
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化学
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DOI
高影响因子
The Innovation
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2021
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IF 0
Hao Tan,Peng Kong,Riguang Zhang,Mengting Gao,Meixian Liu,Xianmo Gu,Weifeng Liu,Zhanfeng Zheng
The controlled generation of reactive oxygen species (ROS) to selectively epoxidize styrene is a grand challenge. Herein, cyano-group-modified carbon nitrides (CNCY x and CN-T y ) are prepared, and the catalysts show better performance in regulating ROS and producing styrene oxide than the cyano-free sample. The in situ diffuse reflectance infrared and density functional theory calculation results reveal that the cyano group acts as the adsorption and activation site of oxygen. X-ray photoelectron spectroscopy and NMR spectrum results confirm that the cyano group bonds with the intact heptazine ring. This unique structure could inhibit H 2 O 2 and ⋅ OH formation, resulting in high selectivity of styrene oxide. Furthermore, high catalytic activity is still achieved when the system scales up to 2.7 L with 100 g styrene under solar light irradiation. The strategy of cyano group modification gives a new insight into regulating spatial configuration for tuning the utilization of oxygen-active species and shows potential applications in industry.
研究领域:
化学工程
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材料科学
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催化反应
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DOI
Nature Communications
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2022
·Vol. 13
·期 1
·1-10
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IF 17.694
Wang Qiyou,Liu Kang,Hu Kangman,Cai Chao,Li Huangjingwei,Li Hongmei,Herran Matias,Lu Ying-Rui,Chan Ting-Shan,Ma Chao,Fu Junwei,Zhang Shiguo,Liang Ying,Cortés Emiliano,Liu Min
Atomically dispersed transition metals on carbon-based aromatic substrates are an emerging class of electrocatalysts for the electroreduction of CO 2 . However, electron delocalization of the metal site with the carbon support via d-π conjugation strongly hinders CO 2 activation at the active metal centers. Herein, we introduce a strategy to attenuate the d-π conjugation at single Ni atomic sites by functionalizing the support with cyano moieties. In situ attenuated total reflection infrared spectroscopy and theoretical calculations demonstrate that this strategy increases the electron density around the metal centers and facilitates CO 2 activation. As a result, for the electroreduction of CO 2 to CO in aqueous KHCO 3 electrolyte, the cyano-modified catalyst exhibits a turnover frequency of ~22,000 per hour at −1.178 V versus the reversible hydrogen electrode (RHE) and maintains a Faradaic efficiency (FE) above 90% even with a CO 2 concentration of only 30% in an H-type cell. In a flow cell under pure CO 2 at −0.93 V versus RHE the cyano-modified catalyst enables a current density of −300 mA/cm 2 with a FE above 90%.
研究领域:
催化化学
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电化学
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材料科学
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DOI
PubMed
高影响因子
CHEMICAL ENGINEERING SCIENCE
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2025
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IF 4.3
Xiaoxiao Yu,Yuanhong Tang,Tong Shao,Xiaohan Xu,Hong Xiao,Xiaojing Wang,Hong Peng,Xiaohui Lu,Shihuai Deng,Gang Yang,Yanzong Zhang,Zhenxing Zeng
The selective removal of highly toxic heavy metal ion Pb(II) from wastewater is of significant importance to the ecological environment and human health, while the development of high performance adsorbents for selective Pb(II) adsorption remains a big challenge. Herein, a cleverly designed heavy metal adsorbent over potassium and cyano modified carbon nitride (KCCN) is proposed, exhibiting excellent performance toward Pb(II) selective removal. The amino and cyano groups in KCCN are found high affinity to that of Pb(II) in such a potassium doped system, as a result showing an excellent Pb(II) selective adsorption performance in the presence of various ions without obviously changing the distribution coefficient K d value. In addition, the adsorption process is found to follow the Langmuir isotherm model and pseudo-second-order kinetic, with a maximum adsorption capacity for Pb(Ⅱ) of 293.26 mg/g. Furthermore, no obvious adsorption capacity drop is found after five cycles of Pb(II) adsorption processes, demonstrating the high reusability on Pb(II) removal.
研究领域:
环境科学
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材料科学
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污染控制
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水处理技术
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吸附材料
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重金属去除
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功能材料
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）