Molecular Catalysis
·
2021
·
IF 5.062
Jia-Yu Lai,Wei-De Zhang,Yu-Xiang Yu
sp hybrid carbon is emerging as a promising unit for covalent modification of organic frameworks and conductive polymers, and has been widely concerned in conjugated polymer catalysts because it can be used to construct π-electron conjugated system. Herein, we provide a simple and effective post reaction strategy to activate g-C 3 N 4 via coupling reactions. The grafted g-C 3 N 4 exhibits improved light absorption and separation of charges, and better water dispersibility along with increased co-catalyst loading sites, which accelerate photocatalytic hydrogen evolution. Photocatalytic H 2 evolution activity of UCN-BTD and UCN-BF, in which terminal amino groups are grafted with 2,1,3-benzothiadiazole,5-(1-propyn-1-yl) or 2,1,3-benzoxadiazole,5-(1-propyn-1-yl), reveals the important role of sp hybrid carbon and electronegativity of the acceptor. The optimized UCN-BTD photocatalyst showed a significant improvement in photocatalytic hydrogen evolution performance (122 μmol·h −1 ), which is nearly five times of that of the pristine g-C 3 N 4 . This work provides insights for the preparation of g-C 3 N 4 -based donor-π-acceptor unit constructed with different conjugated structures.
✓ 已验证
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2017
·
IF 2.714
Ying Li,Zhiquan Yang,Hongguo Zhang,Xiaowen Tong,Jinna Feng
An increasing amount of sewage sludge is produced by wastewater treatment plants worldwide. Therefore, the disposal of sewage sludge is one of the vital environmental issues currently. In the present work, we developed an alternative strategy of converting sewage sludge into porous activated carbon (SAC), and then synthesized a magnetically separable MnFe 2 O 4 -SAC heterogeneous catalyst through an environmentally friendly method. Several characterization techniques such as XRD, FTIR, SEM and XPS indicated the evidence of MnFe 2 O 4 nanoparticles successfully sticking to surface of porous SAC. The MnFe 2 O 4 -SAC composites exhibited stable and excellent catalytic activity in activating persulfate (PS) for the degradation of Orange G (OG) throughout the wide pH range of 3–9, and could be recycled by a magnet without any loss. The activation energy was calculated to be 14.94 kJ mol −1 , indicating that the OG degradation in MnFe 2 O 4 -SAC/PS process required moderate activation energy. The results of heavy metals leaching experiments revealed an excellent stability of the MnFe 2 O 4 -SAC catalyst. Possible reaction mechanism in MnFe 2 O 4 -SAC/PS system was also discussed in detail.
✓ 已验证
DOI
高影响因子
MICROCHIMICA ACTA
·
2024
·Vol. 191
·期 4
·1-10
·
IF 5.3
Xu Yi,Wang Haiping,Bai Qingyan,Ma Shujuan,Bo Chunmiao,Ou Junjie
A carbon dot (CD) was prepared by o -phenylenediamine and water, which showed bright yellow fluorescence under ultraviolet light irradiation (λ = 580 nm), and verified good fluorescence quenching effect on penicillin G sodium (Png-Na). Using methacrylic acid as a functional monomer, ethylene glycol dimethacrylate as a crosslinker, and Png-Na as a template, a kind of composite microsphere combining CD and molecularly imprinted polymer (MIP) was synthesized by surface-initiated atomic transfer radical polymerization (SI-ATRP). For reasons of comparison, we also prepared MIP without CD and non-imprinted polymers (NIPs). Through static and dynamic adsorption experiments, the maximum adsorption capacity was 47.05 mg g −1 and the equilibrium time was 30 min. High-performance liquid chromatography (HPLC) was utilized to determine the content of Png-Na in the spiked milk samples. A sensitive, rapid, and simple method for determination of Png-Na in food samples was developed. The utilized approach enabled the quantification of Png-Na within the concentration range 20–1000 μg L −1 (with a limit of detection of 5 μg L −1 ). The recoveries achieved were in the range 93.3–98.2%, with a relative standard deviation of 1.2–4.2%. The results demonstrated that CD@MIP possessed the capability of specific adsorption and fluorescence detection of Png-Na, enabling simultaneous detection and enrichment of Png-Na in real samples. Graphical abstract
✓ 已验证
DOI
高影响因子
Desalination and Water Treatment
·
2024
·
IF 1
Jianqing Ma,Ziheng Huang,Hao Xi,Yuezhong Wen
ABSTRACT Metal-doping graphitic carbon nitride (g-C 3 N 4 ) is a potential catalyst for the Fenton-like reaction. Selecting an appropriate supporter for this material is essential to improve its catalytic ability and lower the costs. Three common supporters, graphite, activated carbon, and SBA-15, were employed to investigate their effects on the catalyst structure and performances. Results show that graphite could increase the active Fe–N centers due to geometric effects and promote the electron transfer by π–π stacking, and therefore, the Fe-doping g-C 3 N 4 /graphite (FegN/G) composite displayed excellent catalytic ability for the bisphenol A (BPA) removal. In addition, magnetic catalyst was further fabricated through a simple coprecipitation method using Fe 3 O 4 and chitosan-Fe hydrogel. The magnetic catalyst kept in dozens of micrometer size range as well as high activity for the Fenton reaction. Hydroxyl radicals were generated during the reaction process, and 99.9% of the original BPA was therefore degraded and mineralized in 1 h. More importantly, it also exhibits a good reusability and stability, as well as a quick separation performance from the solution when using a magnet, indicating that this magnetic FegN/G composite would be a promising Fenton-like catalyst in practical applications.
✓ 已验证
DOI
高影响因子
Chemical Engineering Journal Advances
·
2021
·
IF 0
Xiaomiao He,Saishuai Bai,Jizhou Jiang,Wee-Jun Ong,Jiahe Peng,Zhiguo Xiong,Guodong Liao,Jing Zou,Neng Li
Excitonic effects induced via Coulomb interactions and an appropriate interfacial contact of electrode modified materials play crucial roles in transfer/separation of interfacial charge carriers during the electrochemical sensing process. Herein, an oxygen vacancy (V o ) mediated step-scheme (S-scheme) heterojunction of WO 2.9 /g-C 3 N 4 was fabricated by electrostatic self-assembly of high-purity commercial WO 2.9 nanoparticles and ultrathin g-C 3 N 4 nanosheets, where g-C 3 N 4 nanosheets were prepared via polymerization followed ultrasonic-assisted exfoliation. The fabricated V o -S-scheme WO 2.9 /g-C 3 N 4 heterojunction-based sensor exhibited superior electrochemical performance for detecting environmental hormone 4-nitrophenol (4-NP). Due to the introduction of V o , an increased free-charge-carriers, a built-in electric field and a high adsorption energy are generated at the heterojunction interface, which all can significantly improve the sensitivity of this proposed sensor. It also showed good reproducibility, high accuracy, good recovery, and strong feasibility for 4-NP detection in real samples. This work not only conduces significantly to understanding the defective structures and S-scheme heterojunctions, but also provides new insights into designing and constructing novel efficient electrochemical sensors.
✓ 已验证
DOI
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2017
·
IF 9.446
Yanbin Wang,Xu Zhao,Di Cao,Yan Wang,Yongfa Zhu
Single-atom dispersed Ag modified mesoporous graphitic carbon nitride (Ag/mpg-C 3 N 4 ) hybrid was synthesized by co-condensation method and employed as a visible light photocatalyst. In the presence of peroxymonosulfate (PMS), Ag/mpg-C 3 N 4 showed excellent performance for the degradation of bisphenol A (BPA). 100% BPA and 80% TOC could be removed with 0.1 g/L catalyst and 1 mM PMS under visible light (λ > 400 nm) within 60 min. The reason for the enhanced performance is possibly due to the synergistic effect of single-atom Ag and mpg-C 3 N 4 . On the one hand, more visible light could be captured with the introduction of Ag; on the other hand, the existence of PMS promotes the separation efficiency of photogenerated electron-hole pairs. Electron spin resonance (ESR) and free radicals quenching experiment suggest that the major reactive oxygen species (ROS) are sulfate radical (SO 4 − ), superoxide radicals (O 2 − ) and photogenerated holes, while the role of hydroxyl radicals ( OH) is insignificant in this process. The findings of this work highlighted the great potential of g-C 3 N 4 as photocatalysts and elucidated a new opportunity for PMS remediation of contaminated water.
✓ 已验证
DOI
高影响因子
Materials Research Express
·
2020
·Vol. 7
·期 1
·015524
·
IF 1.929
Ying Si,Xiaoxian Zhang,Tingting Liang,Xun Xu,Lingfang Qiu,Ping Li,Shuwang Duo
Constructing heterojunction is a promising method to enhance visible-light utility and promote photogenerated e−-h+ pairs separation of g-C3N4. Herein, the present work reported a g-C3N4/Cu2O heterojunction by a facile in situ synthetic strategy. The structure, morphology, optical, electrochemical and photocatalytic properties were investigated. The results showed the combination of g-C3N4 nanosheets and Cu2O nanospheres resulted in the close contact interface and wide visible-light response range, and fast separation of the photo-generated e−-h+ pairs. The pristine g-C3N4 showed weak photocatalytic performance towards methyl orange (MO) under visible-light irradiation, compared with pristine g-C3N4, the photocatalytic degradation rate of optimized g-C3N4/Cu2O composite demonstrates the substantially enhanced photocatalytic activity, which showed no obvious loss after five repeated use. The enhanced performance was ascribed to the synergistic effect of good visible-light harvesting and enhanced separation rate of the charge carriers.
✓ 已验证
DOI
高影响因子
Green Chemical Engineering
·
2021
·
IF 0
Jiajun Wang,Zewei Liu,Shiye Li,Chaoping Li,Su Liu,Jingwen Feng,Rong Tan
Intramolecular acid-base cooperative catalysis is a powerful strategy to promote the nucleophilic additions in synthetic chemistry, since both substrates and nucleophiles can be activated simultaneously, yielding a lower energy reaction pathway. However, the systems often suffer from catalyst quenching due to the mutual neutralization of acid/base sites. Herein, we doped the boron (B) atoms in the tri- s -triazine ring of graphite-like carbon nitride ( g -C 3 N 4 ) framework, to develop the acid-base cooperative catalyst for nucleophilic addition. Characterization results demonstrated a foam-like hierarchical porous structure, as well as the coexistence of Lewis acid and base sites in the as-synthesized samples. As a result, the B-doped g -C 3 N 4 acted as the efficient acid-base cooperative catalysts, significantly promoting the Knoevenagel condensation whose key step involves in nucleophilic addition. A wide range of α, β-unsaturated carbonyl compounds with remarkably high yields (> 90%) was achieved even within 1 h in water, whereas the acid-free or base-free counterpart was far less efficient. In addition, the bifunctional catalysts exhibited excellent reusability with simple treatment. The novel B-doped g -C 3 N 4 catalytic system offers several advantages, such as operational simplicity, mild reaction conditions, high efficiency, and facile reuse of catalyst. All these advantages make it a benign protocol from the sustainability point of view, and inspired us to design the other bifunctional cooperative catalysts for a wide range of sustainable industrial applications.
✓ 已验证
DOI
Journal of Materials Chemistry A
·
2020
·Vol. 8
·期 26
·13299-13310
·
IF 11.301
Cheng-Qun Xu,Wei-De Zhang,Kenzo Deguchi,Shinobu Ohki,Tadashi Shimizu,Renzhi Ma,Takayoshi Sasaki
A facile “one-pot” method to improve the utilization of visible light using organic chemistry protocols is reported. The incorporation of acetylacetone (acac) into the conjugated polymer matrix g-C3N4 derived from urea (UCN) can tune the electronic structure effectively. As a result, the modified g-C3N4 showed a narrowed band gap and enhanced charge carrier migration and separation. Meanwhile, the high utilization ratio of visible light leads to efficient photocatalytic hydrogen evolution, and an apparent quantum efficiency (AQE) as high as 18.8% at 450 nm is achieved, exceeding that of most of the previously reported doped g-C3N4 photocatalysts. Furthermore, density functional theory (DFT) calculations certify the proposed structure of g-C3N4 by incorporation of acetylacetone and explain the enhanced ability to harvest photons due to the introduction of an electron push–pull system into the CN network. In addition, the incorporation of acac into g-C3N4 is also found to be applicable to other precursors (dicyandiamide and thiourea) through similar synthetic routes. Optical absorption under visible light is extended similarly, highlighting the universality of the current strategy. The work provides a route of organic chemistry to design and synthesize functional g-C3N4 with high photocatalytic performance.
✓ 已验证
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2020
·
IF 16.683
Yingying Wang,Hanlin Huang,Zhenzhen Zhang,Cong Wang,Yuying Yang,Qi Li,Dongsheng Xu
Solar-energy-driven CO 2 conversion into value-added chemical fuels holds great potential renewable energy generation. However, most of the photocatalysts facilitate a two-electron reduction process producing CO, hard for the eight-electron CH 4 production pathways which can stockpile more solar energy for further utilization. Herein, we developed an in situ assembly strategy to fabricate the lead-free perovskite Cs 2 AgBiBr 6 @g-C 3 N 4 Z-scheme system in toluene and the Cs 2 AgBiBr 6 @g-C 3 N 4 type-II heterojunction structure in CH 2 Cl 2 . By combining the reducing ability of the conduction band of g-C 3 N 4 and the oxidizing ability of the valence band of Cs 2 AgBiBr 6 perovskite, this Z-scheme system exhibits superior CH 4 production in photocatalytic CO 2 reduction, in contrast to the high CO selectivity for the heterojunction photocatalysts, which is 10-fold and 16-fold higher than that of pure g-C 3 N 4 and pure CABB, respectively. The stability (four consecutive photocatalytic cycles in solvent methanol as sacrificial reagent without obvious decrease of efficiency) and the mechanism (the prominent activity and the high CH 4 production selectivity boosted by Z-scheme system) were demonstrated. In this work, the first report for constructing lead-free halide perovskite Z-scheme and type-II photocatalytic systems for the regulation products selectivity of CO 2 reduction reaction provides a promising strategy for the fabrication other types of inorganic/organic heterojunction systems.
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2021
·
IF 5.316
Hongmei Chen,Yanyun Fan,Hongyan Xu,Danfeng Cui,Chenyang Xue,Wendong Zhang
Herein, a microwave hydrothermal method was developed for constructing g-C 3 N 4 nanosheets. The specific surface area of the photocatalyst using this method was larger than the bulk carbon nitride . In addition, this method yields g-C 3 N 4 with a lower electron-hole recombination rate and faster interface charge transport. Particularly, the conduction band shifts to a more negative position, leading to better reducibility. As expected, the g-C 3 N 4 nanosheets had excellent activity in hydrogen evolution (over 10 times that of the bulk carbon nitride). Additionally, the photocatalyst prepared using this method had good stability in the hydrogen evolution reaction. This work proposes a new, universal, facile and green technique route for preparing g-C 3 N 4 nanosheets.
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Xiang Li,Shengzhao Zhang,Wei Li,Xinhui Xia,Xiuli Wang,Changdong Gu,Jiangping Tu
Replacing organic liquid electrolytes with solid-state electrolytes (SSEs) can effectively improve safety in conventional rechargeable sodium ion batteries. Herein, a mono-comb poly(siloxane-g-ethylene oxide) fiber membrane is proposed to construct fast sodium ion channels for solid electrolyte based on electrospinning polyacrylonitrile (PAN) fiber and the polymerization reaction between polymethylhydrosiloxane (PMHS) and methoxypolyethylene glycols (MPEG). The fiber membrane exhibits a high room-temperature ionic conductivity of 1.06 mS cm −1 , an electrochemical stability window of 4.8 V, and outstanding thermal stability and mechanical strength. A rechargeable Na/Na 3 V 2 (PO 4 ) 3 solid-state full cell based on the polymer electrolyte membrane exhibits a high initial discharge capacity of 114.3 mAh g −1 at 0.2C and a discharge capacity retention of 86.5% after 1000 cycles at 1C. These advantages make the mono-comb poly(siloxane-g-ethylene oxide) fiber membrane have a good prospect in safety sodium ion batteries.
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）