Nanomaterials
·
2021
·Vol. 11
·期 12
·3266
·
IF 5.076
Yang Li,Yue Lu,Zhaoyu Ma,Lianqing Dong,Xiaofang Jia,Junying Zhang
Graphitic carbon nitride (g-C3N4) has been widely studied as a photocatalyst for the splitting of water to produce hydrogen. In order to solve the problems of limited number of active sites and serious recombination rate of charge-carriers, noble metals are needed as cocatalysts. Here, we selectively anchored Pt nanoparticles (NPs) to specific nitrogen species on the surface of g-C3N4via heat treatment in argon–hydrogen gas mixture, thus achieving g-C3N4photocatalyst anchored by highly dispersed homogeneous Pt NPs with the co-existed metallic Pt0and Pt2+species. The synergistic effect of highly dispersed metallic Pt0and Pt2+species makes the catalyst exhibit excellent photocatalytic performance. Under the full-spectrum solar light irradiation, the photocatalytic hydrogen production rate of the photocatalyst is up to 18.67 mmol·g−1·h−1, which is 5.1 times of the catalyst prepared by non-selective deposition of Pt NPs.Keywords:graphitic carbon nitride;platinum;selective deposition;photocatalytic hydrogen production
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Nanomaterials
·
2020
·Vol. 10
·期 4
·805
·
IF 4.324
Bo Zhang,Xiangfeng Peng,Zhao Wang
Composites of g-C3N4/TiO2were one-step prepared using electron impact with dielectric barrier discharge (DBD) plasma as the electron source. Due to the low operation temperature, TiO2by the plasma method shows higher specific surface area and smaller particle size than that prepared via conventional calcination. Most interestingly, electron impact produces more oxygen vacancy on TiO2, which facilitates the recombination and formation of heterostructure of g-C3N4/TiO2. The composites have higher light absorption capacity and lower charge recombination efficiency. g-C3N4/TiO2by plasma can produce hydrogen at a rate of 219.9 μmol·g−1·h−1and completely degrade Rhodamine B (20mg·L−1) in two hours. Its hydrogen production rates were 3 and 1.5 times higher than that by calcination and pure g-C3N4, respectively. Electron impact, ozone and oxygen radical also play key roles in plasma preparation. Plasma has unique advantages in metal oxides defect engineering and the preparation of heterostructured composites with prospective applications as photocatalysts for pollutant degradation and water splitting.Keywords:dielectric barrier discharge plasma;oxygen vacancy;g-C3N4/TiO2;photodegradation;H2evolution
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Huagen Liang,Anhu Wang,Ruolin Cheng,Fu Chen,Palanisamy Kannan,Costas Molochas,Panagiotis Tsiakaras
The emerging photocatalytic production of hydrogen peroxide (H 2 O 2 ) using graphitic carbon nitride (g-C 3 N 4 ) has attracted a lot of attention for its potential applications in various fields. However, However, the catalytic activity of pure g-C 3 N 4 is still limited. Herein, Bi, K co-doped g-C 3 N 4 (Bi x K y -CN) was prepared by co-thermal polymerization of a mixture of potassium nitrate, bismuth nitrate, melamine, and urea. The obtained Bi 3.6 K 3 -CN composite possesses more negative conduction and valence band positions that can, to some extent, enhance photocatalytic performance by lowering the energy barrier of redox reactions and by enhancing electron absorption capacity. Additionally, the pyrolysis process of the potassium nitrate and bismuth nitrate has a considerable impact on the formation of the morphology of g-C 3 N 4 , generating a porous lamellar-structure with nitrogen defects, resulting in increased oxygen adsorption and utilization capacity. These synergistic effects enable Bi 3.6 K 3 -CN to exhibit excellent photocatalytic activity and cycling stability for H 2 O 2 production. After 3 hours of visible light irradiation, the production of H 2 O 2 catalyzed by Bi 3.6 K 3 -CN can reach 1207.72 μmol L -1 , which is 57 times higher than that of pure g-C 3 N 4 .
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2024
·
IF 7.4
Zhilong Zhang,Lushao Gong,Xingyu Zhan,Bo Hong,Xinqing Wang,Yingchun Xia,Yunxiong Zeng
Silver phosphate (Ag 3 PO 4 ) is a promising photocatalyst, but the photo-corrosion issue limits an effective and comprehensive photocatalysis degradation of tetracycline (TC). In this work, a unique graphitic carbon nitride-Ag 3 PO 4 (KCN-AP (40 %) ) core-shell structure was prepared via a simple chemical sedimentation method. The unique graphitic carbon nitride sheet encloses Ag 3 PO 4 to trap excited electrons from the conduction band position of Ag 3 PO 4 , suppressing the reduction of Ag + and Ag metal deposition on the surface of Ag 3 PO 4 . Under visible light irradiation, the optimized KCN-AP (40 %) can photodegrade nearby 100 % of TC within 20 min with a first-order kinetic constant of 0.127 min −1, which is 3.34 and 3.97-folds higher than those of Ag 3 PO 4 and graphitic carbon nitride, respectively. A series of factors that may affect photoactivity of KCN-AP (40 %) including pH, inorganic ions, and organic matter are investigated. In final, the photodegradation mechanisms and intermediates were proposed based on ex-situ HPLC-MS. This work explains the deep decomposition of TC and presents a facile approach for designing and manufacturing Ag 3 PO 4 based nanohybrids.
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
Catalysts
·
2023
·Vol. 13
·期 3
·619
·
IF 3.9
Chen Yang,Xuefeng Hu,Yaxing Bai,Beichuan Cai,Yujie Li
In this study, a simple and low-energy synthesis scheme of Fe single-atom anchored carbon nitride was reported to improve the photocatalytic performance of g-C3N4. Synthesized Fe single-atom doped graphite carbon nitride (Fe-SACs/g-C3N4) showed high activity and stability for the degradation of 2-mercaptobenzothiazole (MBT); under visible light irradiation, 99% of MBT could be degraded within 35 min, and the degradation ability basically did not decline after five cycles, mainly due to the synergistic effect of the Fe single atoms and carbon nitride. The results of X-ray absorption fine structure (EXAFS), X-ray photoelectron spectroscopy (XPS), and density functional theory calculations show that the single-atom Fe forms Fe-N4coordination with pyridine nitrogen to generate a new electron transfer channel, which can significantly improve the in-plane separation and transfer of carriers, finally enhancing the generation of superoxide radicals. This is confirmed by time-resolved photoluminescence, photoelectron chemistry, and electron spin resonance measurements. The main intermediates of MBT degradation were determined using a liquid chromatograph–mass spectrometer (LC-MS), and a possible photocatalytic mechanism based on the quenching experiment and electron paramagnetic resonance (EPR) test was proposed. A deep understanding of the contribution of Fe single-atom sites with clear local coordination structures will help to design effective catalysts for photocatalytic performance.Keywords:graphitic carbon nitride;single-atom;NaBH4reduction;photocatalytic degradation
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2017
·
IF 9.446
Jing Ding,Wei Xu,Hui Wan,Dashui Yuan,Chong Chen,Lei Wang,Guofeng Guan,Wei-Lin Dai
Vacancy defect in the semiconductors plays an important role in the improvement of the electronic structure and the increase of specific reaction sites for reactant molecules, and consequently enhancing the photocatalytic activity of semiconductor photocatalysts. Through high-temperature thermal condensation of a nitric acid-pretreated melamine precursor, nitrogen vacancies were successfully introduced in the framework of g-C 3 N 4 . The nitrogen vacancies located at the uncondensed terminal NH x lattice sites were conducive to the enhancement of optical absorption, the improvement of the separation efficiency of the photogenerated charge carrier and the increase of surface area, which was beneficial to the photocatalytic oxidation process. More significantly, the novel CNNA(X) were used as efficient photocatalysts in the green process of aromatic aldehydes from the photocatalytic selective oxidation of aromatic alcohols and the photocatalytic degradation of organic pollutants. CNNA(X) samples exhibited enhanced photocatalytic activity and excellent recyclability and stability. The 68.3% benzyl alcohol conversion and almost 100% selectivity was observed for the CNNA (0.9) photocatalyst, higher than that of pure g-C 3 N 4 . Meanwhile, CNNA (0.9) showed superior photocatalytic degradation performance of organic dyes (RhB and MO). Furthermore, the underlying photocatalytic oxidation mechanism was proposed by the controlled experiments using radical scavengers.
研究领域:
材料科学
·
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR STRUCTURE
·
2023
·
IF 3.8
Xin Yan,Na Zhang,Zhiliang Liu,Chunfang Du
In this paper, 1T/2H mixed-phase MoS 2 /g-C 3 N 4 composites (1T/2H-MG) were successfully synthesized by a simple two-step calcination method and used for Cr(VI) removal from aqueous environment. A series of characterization methods were used to characterize the microstructure and surface morphology of the prepared materials. The experiment results showed that 1T/2H-MG (1:12) composite with good pH and temperature adaptability could completely remove Cr(VI) (100 mg∙L –1 ) within 50 min and showed an excellent adsorption capacity of 342.06 mg∙g –1 . The presence of abundant sulfur defects in 1T/2H-MG composite could provide more adsorption and reduction active sites, which was the main reason for the enhanced removal efficiency of 1T/2H-MG in comparison with pure MoS 2 and g-C 3 N 4 . This work not only contributes an excellent adsorbent for the wastewater treatment, but also provides evidences for the defects engineering.
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
Gels
·
2024
·Vol. 10
·期 2
·100
·
IF 5
Xue-Chun Yang,Jing-Tai Zhao
Photocatalysis is one of the effective ways to degrade pollutant antibiotics. Agar is used as the adsorption module to provide abundant pore structure. Carbon dots (CDs) are selected as light energy conversion components. Graphitic carbon nitride (g-C3N4) is used as the main material of the catalyst. Agar/CDs/g-C3N4-functionalized aerogel with a unique 3D pore structure is assembled. The Agar/CDs/g-C3N4aerogel shows the highest photocurrent density, which is 3.7 times that of agar, 2.4 times that of 3-g-C3N4and 1.6 times that of Agar/g-C3N4aerogel. Compared with 3-g-C3N4and Agar/g-C3N4aerogel, which can completely remove AMX after 75 min, Agar/CDs/g-C3N4aerogel can degrade amoxicillin (AMX) completely after 45 min of illumination. The reason is that Agar/CDs/g-C3N4aerogel has a larger specific surface area, richer functional groups, a wider spectral range, higher photocurrent density and better carrier migration and separation efficiency. It is a good strategy with which to combine the effects of each component in the ternary system for the efficient photocatalysis of organic pollutants.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2025
·
IF 9
Fulin Wang,Helin Hua,Hui Jia,Dingying He,Zhongyou Jiang,Jiaxin Cao,Shanshan Dong,Zhenxing Zeng,Suhua Chen
The construction of heterojunction is considered to be an effective way to promote the photocatalytic activity, while it is always challenging due to the mismatched lattices of heterojunctional materials and results in an unsatisfactory enhancement of charge carrier separation. It is critical to overcome that lattice mismatch and establish charge transfer channels in heterojunction for achieving high charge transfer and separation. In this study, a red phosphorus/phosphorus doped graphitic carbon nitride (RP/P-CN) type I heterojunction was constructed to boost interfacial charge transfer for Cr(Ⅵ) photoreduction through in situ growing RP on g-C 3 N 4 nanosheets. The formed P − N bonds around interfaces in the RP/P-CN allowed photoexcited charge to rapidly transfer from the conduction band of P-CN to that of RP, which contributed to the significant achievement of Cr(Ⅵ) reduction. The constructed interfacial charge transfer channels largely promoted the photoexcited charge carrier separation in the RP/P-CN. Additionally, the simultaneous RP formation and P doping significantly enhanced the visible light response and the adsorption efficiency of Cr(Ⅵ). As a result, RP/P-CN 1:5 could achieve 99.1 % removal of Cr(Ⅵ) after 20-min visible light irradiation with an achieved apparent kinetic rate constant (k app ) of 0.2289 min −1 , which were much better than the 19.2 % of Cr(Ⅵ) removal by pure g-C 3 N 4 and presented a 21-fold higher k app than pure g-C 3 N 4 (0.0108 min −1 ) achieved, respectively. This study provides a new strategy to design an efficient g-C 3 N 4 based metal-free heterojunction for Cr(Ⅵ) photoreduction.
研究领域:
材料科学
·
环境科学
·
光催化
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 13.2
Zhihao Song,Lei Xu,Cheng Xie,Yanzhi Liu,Zhaohui Han,Junyu Lu
Visible light-driven photo-oxidation reactions hold significant potential for the treatment of gaseous pollutants. However, the weak internal electric field of carbon nitride (g-C 3 N 4 ) leads to sluggish migration of photogenerated carriers, while inefficient electron-hole pair separation further limits the overall photo-oxidation efficiency. In this study, nitrogen-vacancy (Nv) rich crystalline (Cs)/amorphous g-C 3 N 4 was synthesized using a two-step calcination method. The increased crystallinity facilitates faster carrier migration, broadens the potential difference between the crystalline and amorphous regions, and enhances the piezoelectric response. On the other hand, the incorporation of nitrogen vacancies (Nv) introduces asymmetry, generating a dipole field that significantly improves the efficiency of electron-hole pair separation. Moreover, the presence of NV improves the adsorption and activation of O 2 molecules, promoting the photo-oxidation of adsorbed NO via the generation of single linear oxygen ( 1 O 2 ). The resulting material, Cs-Nv-630, demonstrated excellent oxidative NO removal efficiency, achieving a removal rate of 95.3 % under visible light irradiation. This study highlights a novel strategy for enhancing photo-oxidation activity through structural engineering, leveraging crystallinity and dipole fields to optimize carrier migration and complexation.
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
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2024
·
IF 9.4
Huagen Liang,Haoran Wang,Anhu Wang,Ruolin Cheng,Shengyu Jing,Fu Chen,Palanisamy Kannan,Georgia Balkourani,Panagiotis Tsiakaras
Graphitic phase carbon nitride (g-C 3 N 5 ), as a novel n -type metal-free material, is employed as a visible light-receptive catalyst because of its narrow band gap and abundant nitrogen. To overcome the low carrier mobility efficiency of g-C 3 N 5 , its modification by K ions was adopted. In addition, In 2 S 3 was selected to couple with modified g-C 3 N 5 to overcome the recombination of photogenerated e − /h + . As a novel photocatalytic material, it was proven to possess a high visible light absorption capacity and a strong H 2 O 2 production ability (up to 3.89 mmol⋅L -1 in 2 h). Moreover, a S-scheme heterojunction structure was successfully constructed between the two materials, which was tested and confirmed to be successful in raising the photogenerated e − /h + separation efficiency. Ultimately, the primary processes of photocatalytic H 2 O 2 production were summarized by superoxide radical and rotating disc electron measurements. This research provides a fresh perspective for the synthesis of C 3 N 5 -based S-scheme heterojunction photocatalysts for producing H 2 O 2 .
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CARBON
·
2024
·
IF 10.5
Yu Zhang,Jingde Luan,Panpan Li,Longde Jiang,Haibin Yan,Wengang Liu,Zheng Yan
Water-based homogeneous pre-assembly and thermal polycondensation were used to prepare carbon-doped oxygen-bridged layer-twisted graphite carbon nitride (g-C 3 N 4 ) heterojunction for highly efficient photocatalytic hydrogen evolution (PHE). Despite the narrow band gap of around 0.91 eV, g-C 3 N 4 heterojunction exhibited an excellent hydrogen evolution rate (563.87 μmolg −1 h −1 ) in 30 % methanol/water solution without precious metal assisting catalysts, 36.85 times higher than g-C 3 N 4 . C doping in heptazine ring and bridging O caused the adjacent layer of g-C 3 N 4 to twist by 11° in three-dimensional space. Noticeably, carbon doping in triazine ring was favorable to the establishment of build-in electric field between adjacent layers owing to the delocalized large π bonds . Bridging oxygen acted as a conversion switch for electron storage and transport of photogenerated charge from innerlayer (unmodified layer) with high Fermi level to outlayer (modified layer) with low Fermi level. This work provided an insightful guidance to novel layer-twisted g–C 3 N 4 –based photocatalysts for efficient H 2 production.
研究领域:
材料科学
·
能源化学
·
理论计算
✓ 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）