Crystals
·
2020
·Vol. 10
·期 6
·490
·
IF 2.404
Weiguang Zhong,Dan Wang,Congcong Jiang,Xiaolei Lu,Lina Zhang,Xin Cheng
Cement-based composite is one of the essential building materials that has been widely used in infrastructure and facilities. During the service of cement-based materials, the performance of cement-based materials will be affected after the cement surface is exposed to pollutants. Not only can the surface of cement treated with a photocatalyst degrade pollutants, but it can also protect the cement-based materials from being destroyed. In this study, graphite carbon nitride-silica composite materials were synthesized by thermal polymerization using nanosilica and urea as raw materials. The effect of nanosilica content and specific surface area were investigated with the optimal condition attained to be 0.15 g and 300 m2/g, respectively. An X-ray diffractometer, thermogravimetric analyzer, scanning electron microscope, a Brunauer–Emmett–Teller (BET) specific surface area analyzer and ultraviolet-visible spectrophotometer were utilized for the characterization of as-prepared graphite carbon nitride-silica composite materials. Subsequently, the surface of cement-based materials was treated with graphite carbon nitride-silica composite materials by the one-sided immersion and brushing methods for the study of photocatalytic performance. By comparing the degradation effect of Rhodamine B, it was found that the painting method is more suitable for the surface treatment of cement. In addition, through the reaction of calcium hydroxide and graphite carbon nitride-silica composite materials, it was found that the combination of graphite carbon nitride-silica composite materials and cement is through C-S-H gel.Keywords:graphite carbon nitride;silica;visible light catalysis;cement
研究领域:
材料科学
·
环境工程
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 114
·113570-113575
·
IF 3.289
Wenyu Gao,Xiaofang Wang,Pei Li,Qiongtao Wu,Fang Qi,Songmei Wu,Yu Yu,Kejian Ding
A highly sensitive and selective electrochemical sensor is developed for the detection of cadmium with a nanosheet graphitic carbon nitride (g-C3N4) modified electrode. The g-C3N4 nanosheet modified glassy carbon electrode detects heavy metal not only by electrostatic interactions, but also by intercalating the holes during differential pulse anodic stripping voltammetry (DPASV) measurements for Cd2+ in aqueous solution. The calibration curves for Cd2+ covered two ranges varying from 1 nM to 1 μM and 1 μM to 100 μM. The limitation of detection (LOD) is estimated to be 0.5 nM for Cd2+, which is 53 times lower than the guideline values of drinking water given by the World Health Organization (WHO). In addition, the good repeatability and stability of the modified electrode is feasible for heavy metal detection in this study.
研究领域:
环境科学
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
CHINESE JOURNAL OF CATALYSIS
·
2016
·
IF 2.628
Cheng Wang,Liya Hu,Meiyin Wang,Yuanhang Ren,Bin Yue,Heyong He
A series of graphitic carbon nitride supported vanadium catalysts ( x V/g-C 3 N 4 ) with different vanadium contents ( x /%) were prepared by impregnation. XRD, FT-IR, TEM, TG-DTG, nitrogen adsorption and XPS characterizations were conducted which revealed a strong interaction between the vanadium species and g-C 3 N 4 support. 8V/g-C 3 N 4 exhibited the highest activity and showed stable recyclability in the benzene hydroxylation reaction with a benzene conversion of 24.6% and phenol selectivity of 99.2% under the optimized conditions. The excellent catalytic performance of x V/g-C 3 N 4 was due to the integration of vanadium species with high catalytic activity and the g-C 3 N 4 support in their interaction with the benzene substrate
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2019
·
IF 14.229
Guiming Ba,Zhiwei Liang,Haiping Li,Na Du,Jianqiang Liu,Wanguo Hou
Graphite carbon nitride (CN) is considered as a promising photocatalyst for solving current energy and environmental crises, but its practical application is still restricted by fast recombination of photogenerated charge carriers, low specific surface area, and narrow visible light absorption range. Herein, oxygen-modified CN (MCN) with simultaneous formation of massive mesopores and homojunctions was successfully synthesized by calcining the precursor, a cyanuric acid (CYA)-loaded melamine (MA) hierarchical structure composed of nanobelts, which was prepared for the first time. MCN exhibits accelerated charge separation, increased specific surface areas, and enhanced visible light absorption, compared with CN, and these jointly render the photocatalytic hydrogen evolution rate of MCN (934 μmol h −1 g −1 ) be about five times higher than that of CN (163 μmol h −1 g −1 ). MCN also exhibits much faster singlet oxygen generation and higher photoactivity in organic degradation. The MA hierarchical structure and CYA synergistically formed the new mesopores and C O C bonds in MCN, which cause prominent upper shift of the Fermi level and enhanced photoabsorption of MCN. Besides, electronic microscopy images distinctly show two different sorts of regions in MCN, i.e. those with massive and few mesopores (marked as MPCN and NPCN), respectively. Therefore, MPCN/NPCN homojunctions were probably constructed in MCN, which leads to the accelerated charge separation. This work gives a way to form simultaneously mesopores and homojunctions in CN and illustrates the formation mechanism, which can effectively direct synthesis of similar photocatalysts.
研究领域:
材料科学
·
环境科学
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
·
2021
·
IF 4.098
Yuning Yang,Han Wang,Yiwei Wu,Xiaoxiao Yu
In this work, a strong blue-emitting fluorescent biosensor based on graphite carbon nitride nanoparticles (GCNNs) (E x = 340 nm and E m = 435 nm) was synthesized by a facile one-step hydrothermal method. With the aid of hydrogen peroxide and horseradish peroxidase, pyrocatechol structure of dopamine (DA) was oxidized to o-quinone structure of polydopamine (PDA) by hydroxyl radical. PDA was able to rapidly and significantly quench fluorescence of GCNNs . In the meanwhile, oxidative self‐polymerization from DA to PDA would be blocked by antioxidants, such as glutathione (GSH) and ascorbic acid (AA). Thus, the fluorescence of GCNNs@DA sensor would be recovered owing to the decrease of o-quinone. Based on above-mentioned dual recognition strategy of “turn-off” and “turn off–on”, a fast, simple and ultrasensitive method was developed to measure DA and antioxidants. Under the optimal experimental conditions, the detection limits of DA, GSH and AA were 0.064 μmol L −1 , 0.11 μmol L −1 and 0.16 μmol L −1 with relative standard deviations of 1.7%, 9.3% and 8.0%, respectively. As one of metal-free quantum dots, our GCNNs-based sensors were also successfully applied to the determination of DA as well as GSH and AA in human serum. The recoveries for the spiked samples were in the range of 93.8%-109% and 95.0%-110% of DA and antioxidants, which shows great promise to clinical application.
研究领域:
生物化学
·
分析化学
·
医学诊断
✓ 已验证
产品关联
DOI
PubMed
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2021
·Vol. 46
·期 8
·3588-3594
·
IF 3.591
Qingqing Gao,Qian Lei,Ruoyan Miao,Manyi Gao,Hu Liu,Qin Yang,Yequn Liu,Fang Song,Yongsheng Yu,Weiwei Yang
Polymeric carbon nitride (PCN) is an emerging metal-free photocatalyst with high stability but is plagued by low photocatalytic efficiency due to the rapid charge carrier recombination behavior. Herein, Bi-doped graphitic carbon nitride nanotubes (BCN nanotubes) with a porous structure have been facilely prepared by one-step thermal polymerization of mixtures of melamine, urea and bismuth nitrate pentahydrate under an Ar atmosphere. With unique structural advantages for charge carrier transfer, light harvesting, and large surface area, the as-prepared BCN nanotubes exhibit excellent photocatalytic activity for the degradation of Rhodamine (Rh) B with a 26.8-fold higher reaction rate than that of PCN under visible light irradiation. This work provides informative principles about the synthesis of PCN with controlled morphology and element doping simultaneously for the photocatalytic degradation of chemical pollutants.
研究领域:
材料科学
·
环境科学
✓ 已验证
DOI
高影响因子
Catalysts
·
2023
·Vol. 13
·期 3
·600
·
IF 3.9
Jiajia Wei,Xing Chen,Xitong Ren,Shufang Tian,Feng Bai
Due to the different electron affinity, the construction of a donor-acceptor (DA) system in the graphitic carbon nitride (g-CN) matrix is an attractive tactic to accelerate photo-induced electron-holes separation, and then further elevate its photocatalytic performance. In this work, perylene tetracarboxylic dianhydride (PTCDA) with magnificent electron affinity and excellent thermal stability was chosen to copolymerize with urea via facile one-pot thermal copolymerization to fabricate g-CN-PTCDA equipped with DA structures. The specific surface area of g-CN-PTCDA would be enlarged and the visible light absorption range would be broadened simultaneously when adopting this copolymerization strategy. A series of characterizations such as electron paramagnetic resonance (EPR), steady and transient photoluminescence spectra (PL), electrochemical impedance spectroscopy (EIS), and photocurrent tests combined with computational simulation confirmed the charge separation and transfer efficiency dramatically improved due to the DA structures construction. When 0.25% wt PTCDA was introduced, the CO evolution rate was nearly 23 times than that of pristine g-CN. The CO evolution rate could reach up to 87.2 μmol g−1h−1when certain Co2+was added as co-catalytic centers. Meanwhile, g-CN-1 mg PTCDA-Co exhibited excellent long-term stability and recyclability as a heterogeneous photocatalyst. This research may shed light on designing more effective DA structures for solar-to-energy conversion by CO2reduction.Keywords:donor-acceptor;graphitic carbon nitride;PTCDA;photocatalysis;CO2reduction
研究领域:
材料科学
·
环境科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2017
·
IF 2.843
Dong Yang,Hongjian Zou,Yizhou Wu,Jiafu Shi,Shaohua Zhang,Xiaodong Wang,Pingping Han,Zhenwei Tong,Zhongyi Jiang
NAD(P)H is a critical cofactor (biological source of hydrogen) that participates in many enzymatic hydrogenations for energy conversion and storage with resultant oxidation to NAD(P)+. Due to its high cost, the regeneration of NAD(P)H is a critical and feasible way to ensure the sustainability of these enzymatic hydrogenations. Intrigued by the photoreaction process in thylakoid membrane, we explored a two-dimensional (2D) isotype heterojunction photocatalyst, termed as quantum dots@flake graphitic carbon nitride (QDs@Flake g-C3N4), for visible-light-driven NAD(P)H regeneration. The catalyst was synthesized by one-step calcination using cyanamide-treated cyanuric acid–melamine (CM) complex as starting material, where cyanamide plays dual roles: (a) assisting the transformation of CM from bulky to stacked structure and further to flakes after calcination, and (b) acting as raw material for the generation of QDs on the flakes. To replicate both the functional and structural properties of the natural photoreaction system, QDs@Flake g-C3N4 exploited the two types of g-C3N4 (i.e., QDs and flake) and a heterojunction interface to, respectively, mimic the functional components of light-harvesting systems (LHSs, i.e., photosystem I and photosystem II) and electron transport chains (ETCs), and utilize the flake structure as the analogue of 2D thylakoid membrane. Therefore, QDs@Flake g-C3N4 showed remarkably improved capability in visible light harvesting and charge separation, and exhibited elevated performance in photocatalytic NADH regeneration with a regeneration yield of up to 40%. The NADH regeneration approach was then coupled with alcohol dehydrogenase catalyzed hydrogenation of formaldehyde, achieving continuous methanol production.
研究领域:
材料科学
·
生物化学
·
光催化
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2022
·
IF 7.139
Weili Kong,Mochi Hong,Wen-Sheng Zou,Qin Li,Yu Xu,Yonglong Xu,Pingping Wu,Jun Zhang,Yaqin Wang
In this paper, we designed a composite photocatalytic system in which cobalt nanoparticles (Co NPs) are attached to nitrogen-doped carbon (N- d -C) and co-bonded to the surface of the noted photocatalyst graphite carbon nitride (g-C 3 N 4 ), showing an excellent photocatalytic hydrogen production . The bulk g-C 3 N 4 was formed in the first thermal treatment in air using melamine as a precursor. Subsequently, the secondary calcination under N 2 led to the synchronous fabrication of N- d -C/Co NPs and their combination with g-C 3 N 4 to form a novel ternary photocatalyst (g-C 3 N 4 /N- d -C/Co NPs). Co NPs exposed on the surface of the nanomaterials endowed much more reaction sites than g-C 3 N 4 for photocatalytic hydrogen production. Meanwhile, the embedded N- d -C provided an additional transfer approach for photocarriers. The as-prepared composite nanomaterials own a relatively high specific surface area of 97.45 m 2 g −1 with an average pore size of 3.83 nm. As a result, compared with pristine g-C 3 N 4 (∼25.35 μmol g −1 h −1 ), the photocatalytic performance was increased by over 10 times (∼270.05 μmol g −1 h −1 ). Our work gives a novel approach for highly active g–C 3 N 4 –based photocatalysts in the field of photocatalysis .
研究领域:
材料科学
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2023
·
IF 6.2
Fangwei Qi,Huixing Li,Gang Chen,Shuping Peng,Cijun Shuai
Graphite carbon nitride (g-C 3 N 4 ) was regarded as a promising photodynamic antibacterial material due to its desirable bandgap and favorable visible light absorption. However, its photodynamic antibacterial effect was weakened by too rapid recombination of electron-hole and hypoxic environment of infection site. Herein, an oxygen self-supplied heterojunction was constructed via in-situ growing CuO 2 on g-C 3 N 4 (CuO 2 @g-C 3 N 4 ). For the heterojunction, on the one hand, it could response to the weak alkaline of infected site to decompose to CuO@g-C 3 N 4 , where CuO could form a built-in electric field with g-C 3 N 4 to promote the electron-hole separation. On the other hand, it could produce oxygen in the decomposition process, which achieved oxygen self-supply for photodynamic reaction. Subsequently, the heterojunction was introduced into poly-para-dioxane (PPDO) scaffold fabricated by laser additive manufacturing . The photoluminescence results confirmed that the electron-hole separation efficiency was significantly improved. The release kinetics results indicated that the scaffold could continuously release oxygen. As a consequence, the reactive oxygen species (ROS) generation ability of the scaffold was increased by approximately tenfold. The generated ROS effectively killed bacteria by disrupting membrane structure, triggering protein leakage and depleting glutathione . Eventually, the scaffold exhibited an antibacterial rate of 89.8% and 90.5% against S. aureus and E. coli , respectively.
研究领域:
材料科学
·
生物医学工程
·
微生物学
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2024
·
IF 8.1
Yu Zhang,Jingde Luan,Longde Jiang,Wengang Liu,Zheng Yan,Yu Bai
The enhanced driving force of charge carriers is crucial for improving the efficiency of photocatalytic hydrogen evolution of graphite carbon nitride (CN). N vacancy, grafted O and bridging C are successfully constructed to fabricate novel CN based photocatalyst (COV N @CN-20), using urea as precursor, maltodextrin as carbon and oxygen source via two-stage thermal polymerization. N vacancies serve as electron trap to providing more activation sites for hydroxyl and hydrogen ions. The surface grafted O becomes the electron enrichment center, providing electrons for hydrogen evolution reaction. The bridging C replaces the bridging N in the heptazine skeleton, enhancing the delocalized π state of electrons within the inner layer. The coupling effect of N vacancy, grafted O and bridging C facilitates band gap narrowing and promotes the efficient separation and migration of surface charge in COV N @CN-20. The experiments of photocatalytic hydrogen production indicate that the hydrogen yield of COV N @CN-20 reaches 1720.32 μmol g −1 without the need for any co-catalysts, 37.50 times than that of CN. The theoretical calculations indicate that the coupled surface-internal bridging engineering optimize its inherent electronic properties through surface defects, self-build-in electric field and electron enrichment, thereby improving carrier utilization for efficient hydrogen production.
研究领域:
材料科学
·
能源化学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry A
·
2024
·
IF 10.7
Ying-jie Sun,Xue-ting Liu,Xin-jie Zhao,Xiao-jing Wang,Jun Zhao,Yu-pei Li,Hui-ying Mu,Fa-tang Li
The tuning of the Mott–Schottky barrier for obtaining superior separation and transfer efficiency of photogenerated carriers is significant for metallic co-catalyst-modified photocatalytic materials. Metallic cobalt phosphide (CoP) has been regarded as a promising co-catalyst for replacing Pt in the photocatalytic hydrogen evolution reaction (HER). However, it is still challenging to enhance the kinetics of CoP for the HER while lowering the Schottky barrier and improving electron transport properties. Herein, Mo metal was introduced into CoP and graphite carbon nitride (g-C3N4) as a bridge of electron transfer channels for synchronous tuning of the Schottky barrier. The analyses showed that the original Schottky contact between CoP and g-C3N4 was transformed into an ohmic contact by the introduction of metallic Mo, which caused a decrease in the Schottky barrier and even improved the charge transfer, lowered the HER potential, and accelerated the HER kinetics process of CoP. After rational assembly, the optimum photocatalyst (Mo-CoP@CN-1.0) showed a remarkable photocatalytic HER rate of 1.47 mmol g−1 h−1 under visible light irradiation, which was about twice as high as that of the optimal Pt modified g-C3N4. This study provides a new prospect for the rational design of a high-efficiency co-catalyst and provides a new way for regulating the Mott–Schottky barrier.
研究领域:
材料科学
·
光催化
✓ 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）