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.
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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.
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DALTON TRANSACTIONS
·
2019
·Vol. 48
·期 10
·3486-3495
·
IF 4.052
Juying Lei,Bin Chen,Weijia Lv,Liang Zhou,Lingzhi Wang,Yongdi Liu,Jinlong Zhang
A TiO2/g-C3N4 composite photocatalyst with an inverse opal structure and heterojunction has been successfully prepared by a relatively facile approach. The catalyst was characterized by a combination of XRD, SEM, HRTEM, XPS, PL, EIS and DRS techniques and applied for the photocatalytic degradation of organic pollutants represented by Rhodamine B, phenol and levofloxacin. The results of RhB degradation showed that the rate constant of inverse opal TiO2/g-C3N4 with the best compound ratio is 0.184 min−1, which is 2.7 times faster than that of normal TiO2/g-C3N4 and 4.2 times faster than that of inverse opal TiO2. The enhancement of photocatalytic activity may be attributed to the matched overlapping band structure and the interaction between inverse opal g-C3N4 and TiO2. The inverse opal structure of g-C3N4 has improved the optical absorption properties of g-C3N4 and the interaction between inverse opal g-C3N4 and TiO2 creates more interfaces for the efficient transfer of photogenerated electron–hole pairs to restrict the recombination, which was proved from the photoluminescence spectra (PL). Moreover, a possible photocatalytic mechanism has been tentatively proposed according to the experimental results. All in all, both the inverse opal structure and heterojunction construction play significant roles in the excellent photocatalytic degradation performance according to the mechanism investigation.
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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.
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Chemical Engineering Journal Advances
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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.
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JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY
·
2022
·Vol. 97
·期 7
·1717-1725
·
IF 3.709
Yuanzhi Hong,Xue Zhang,Xue Lin,Enli Liu,Longyan Wang,Weilong Shi,Xixin Duan
BACKGROUND The photocatalytic reforming (PR) of abundant and renewable cellulosic biomass resources into hydrogen (H 2 ) fuel is a promising approach for solar-to-chemical energy conversion. Although the related PR reactions have been investigated, the majority of previous works were operated in strong alkaline conditions (pH > 14) owing to the insolubility of cellulose, and used UV-driven titania (TiO 2 )-based materials as photocatalysts. RESULTS To this end, for the first time, we present ultrathin 2D graphitic-like carbon nitride (g-C 3 N 4 ) nanosheets (CNNs) derived from the thermal-oxidation strategy for PR of cellulose into H 2 under neutral conditions. Compared to bulk g-C 3 N 4 (BCN), the resulting ultrathin CNNs with an average thickness of 6 nm showed a remarkably increased surface area, significantly improved photogenerated charge mobility, higher electrical conductivity and stronger photooxidation capacity. Consequently, the as-prepared CNNs displayed dramatically enhanced visible-light PR activity for H 2 evolution that was 3.93-fold greater than that of BCN under the same conditions. CONCLUSION Our study achieves an available avenue for PR of cellulose into H 2 under neutral conditions without the need for value-added sacrificial reagents, which will bring about potential applications in sustainable H 2 production through the PR reaction. © 2022 Society of Chemical Industry (SCI).
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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.
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高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2022
·Vol. 139
·期 24
·52346
·
IF 3.057
Yuhan Xu,Chenyu Zhao,Zhiyuan Guo,Wenjie Dong,Xiucai Liu,Weihong Guo
Polyamide is an engineering plastic, which has been widely used in industry and life. Polyamide 56, as a green and environmentally friendly bio-based product, is gradually replacing traditional petroleum-based products. However, in terms of auto parts, communication equipment, and mechanical products, a single polyamide monomer is difficult to meet the end-use standard. EPDM-g-MAH (ethylene propylene diene monomer grafted with maleic anhydride) is melt blended with bio-based polyamide 56 (PA56) in a twin-screw extruder to obtain polyamide elastomers with different formulations. Subsequently, its morphology and structure, thermodynamic properties, crystallinity, and mechanical properties were analyzed. The test results show that the composites containing 10% EPDM-g-MAH have better impact resistance and thermal properties in the range of adding 0‑20 wt% EPDM-g-MAH. In the fracture morphology analysis, it is found that the interface between the rubber phase and the polyamide phase fused well, and the elastomer showed the ductile fracture.
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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
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Journal of Environmental Chemical Engineering
·
2024
·
IF 7.4
Xiaodong Yang,Minghui Li,Zhiyong Hou,Xuefei Yang,Yuanxia Guo,Shuaiqi Luo,Jin Zhao,Kai Wang,Pengkai Sun,Qiang Yang,Rui Chen,Shuo Yang,Xin Lu,Lulu Liu,Lili Wang,Ye Han,Fanming Zeng,Bin Gao
Norfloxacin, a quinolone antibiotic pollutant, posed a significant threat to environment and human being health. In this study, hydrotalcite-based g-C 3 N 4 composites were produced using electrostatic self-assembly and the structural memory effect of hydrotalcite to optimize their adsorption-degradation of norfloxacin under visible-light illumination. Optimized hydrotalcite and g-C 3 N 4 composite (750°C, 40 wt% of g-C 3 N 4 ) exhibited a highest photo-degradation rate constant of 1.8×10 −2 min −1 with 83.98 % norfloxacin degradation achieved within 1.5 h under visible-light, surpassing that of bare g-C 3 N 4 and hydrotalcite photocatalysts. The synergistic effects of the composite, such as uniform flower-like micro-morphology and rich mesoporous structure, resulted in a large specific surface area (58.67 m 2 /g), abundant active sites, and good photo-generated charge separation efficiency. All these facilitated both sorption (7.95 mg/g) and subsequent visible-light degradation of norfloxacin. Furthermore, the superior photocatalytic performance observed in the degradation of norfloxacin under visible-light illumination was assigned to the effective transport of photogenerated electrons and holes between hydrotalcite and g-C 3 N 4 components. The work highlights the potentials of hydrotalcite and g-C 3 N 4 composites as an excellent photocatalyst for environment remediation and water treatment.
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高影响因子
Desalination and Water Treatment
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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.
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高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2024
·Vol. 59
·期 8
·3573-3584
·
IF 3.5
Xu Man,Luo Yongping,Zeng Linsheng,Huang Ping,Xu Shunjian,Liu Yike,Wang Yongya,Li Xianchang,xie Yu
In consideration of the increased activity of Pt-based catalysts for methanol oxidation in direct methanol fuel cells, it is necessary to apply an ideal support in the construction of Pt-based catalyst for methanol oxidation. In this study, Ag/g-C 3 N 4 nanosheets (Ag/GCNN) nanocomposites with different Ag contents were synthesized and used as the progressive support to construct Pt/Ag/GCNN catalyst. As a nitrogen-rich polymeric semiconductor, GCNN is easily coordinated with various metals. The introduction of Ag nanoparticles can improve the electrical conductivity of the catalyst and cooperate with Pt for optimizing the performance of electrocatalytic oxidation of methanol. The electrochemical experiment results demonstrated that Pt/Ag/GCNN has higher electrocatalytic activity and stability for methanol oxidation than Pt/GC and Pt/GCNN. The mass activity of Pt/Ag/GCNN-0.6 (18.66 mA mg Pt −1 ) is 7.07, 4.60 and 1.26 times that of Pt/GCNN (4.06 mA mg Pt −1 ), Pt/Ag/GCNN-0.4 (4.06 mA mg Pt −1 ) and Pt/Ag/GCNN-0.8 (14.76 mA mg Pt −1 ) at the forward peak potential. The J f / J b ratio of Pt/Ag/GCNN-0.6 is 3.31, which is bigger than that of Pt/GCCN (2.62), Pt/Ag/GCNN-0.4 (2.69), and Pt/Ag/GCNN-0.8 (2.56). A suitable mechanism was proposed to explain that Ag/GCNN supported Pt catalyst can improve the CO toxicity resistance and electrocatalytic performance. Based on the coordination of GCNN, Ag was first modified to form a support, and then the remaining coordination sites were used to support Pt. It provided a new strategy for the design of catalysts for methanol electrooxidation. Graphical abstract
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