APPLIED SURFACE SCIENCE
·
2018
·
IF 4.439
Lianying Lu,Guohong Wang,Min Zou,Juan Wang,Jun Li
Hierarchical TiO 2 /g-C 3 N 4 heterojunction photocatalysts with well-defined multiscale porous TiO 2 framework are synthesized by simply calcinating tetrabutyl titanate and melamine precursors. The samples have been characterized by XRD, XPS, SEM, TEM, FTIR, nitrogen absorption-desorption equipment and TGA. The photocatalytic activity of these samples has been investigated in photo-degradation of Rhodamine B (RhB). The results show that calcining temperature critically affects the microstructure, surface area, interface structure and catalytic properties of the prepared samples. At the optimal calcining temperature of 550 °C, the apparent reaction rate constant of the catalyst is 55.0 × 10 −3 min −1 , which is 16.2 fold of pure TiO 2 (3.4 × 10 −3 min −1 ) and 3.4 fold of pure g-C 3 N 4 (16.4 × 10 −3 min −1 ), respectively. The strengthened visible-light-driven photocatalytic activity is attributed to the formation of a unique Z-scheme TiO 2 /g-C 3 N 4 heterojunction due to C- or N-doping at the surface of the porous TiO 2 framework. This mechanism explains the observation in a series of radical trapping experiments that superoxide ions and photo-generated holes play major roles in the photo-decolorizing process while hydroxyl radicals are also involved with a minor role.
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高影响因子
Biochar
·
2022
·Vol. 4
·期 1
·1-19
·
IF 11.452
Han Yu,Gan Lu,Gong Han,Han Jiangang,Qiao Weichuan,Xu Lijie
Metal-free photocatalysts have attracted growing concern recently. Herein, the composites combining g-C 3 N 4 with wood pulp cellulose biochar (WPBC/g-C 3 N 4 ) were synthesized to effectively activate peroxymonosulfate (PMS) under visible light for the degradation of diclofenac (DCF). The incorporation of WPBC endowed g-C 3 N 4 with enhanced visible light absorption, improved charge separation capability, reduced electrical conductivity, and increased photocatalytic and PMS activation capability. Based on quenching tests, electron paramagnetic resonance (EPR), electrochemical analysis and solvent exchange experiments, both radical and nonradical mechanisms were proposed. Radical species including ·OH, h + , ·O 2 – were identified to contribute to DCF degradation. The 1 O 2 and electron transfer were the dominant nonradical pathways for DCF degradation. Moreover, the common influencing factors were examined, and DCF concentration was the most influential factor based on principal component analysis. Generally, the composites exhibited good reusability during consecutive runs. Based on HPLC/MS analysis, four intermediates were detected and the possible DCF degradation pathway was proposed. This work provided a potential strategy based on metal-free WPBC/g-C 3 N 4 for the photocatalytic activation of PMS to effectively degrade emerging contaminants in wastewater. Graphical abstract
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高影响因子
NEW JOURNAL OF CHEMISTRY
·
2022
·Vol. 46
·期 47
·22830-22840
·
IF 3.925
Jiajun Nong,Yuexiang Jin,Jun Tan,Hongxia Ma,Yuan Lian
Realizing highly efficient utilization of solar energy for solving problems of environmental pollution and energy shortage has attracted increasing attention. Herein, Z-scheme two-dimensional (2D)/2D NiCo-LDH/g-C3N4 (LDH/CN) heterojunction composites were synthesized, which showed enhanced photocatalytic performance for tetracycline hydrochloride (TC) degradation and hydrogen (H2) generation under visible light irradiation. A 2D/2D heterojunction structure was formed between NiCo-LDH nanosheets (LDH) and g-C3N4 (CN), which was beneficial for the effective separation of photogenerated charge carriers. The active species of hydroxyl (˙OH), superoxide (˙O2−) and hole (h+) radicals contributed to TC photodegradation. The optimum photocatalyst showed a remarkably enhanced photocatalytic capability with a hydrogen generation rate of 451.7 μmol g−1 h−1. The improved photocatalytic activities may be attributed to the synergistic effects of the increased absorption of visible light, the separation efficiency of carriers and the 2D/2D heterostructure. A Z-scheme photocatalytic mechanism was proposed for the LDH/CN composite, showing dual advantages of a high redox ability and efficient charge carrier separation.
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高影响因子
ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY
·
2019
·
IF 4.527
Wei Liu,Jiabin Zhou,Jun Yao
In this work, the shuttle-like CeO 2 modified g-C 3 N 4 composite was synthesized and was combined with persulfate (PS) for the efficient photocatalytic degradation of norfloxacin (NOR) under visible light. Scanning and transmission electron microscopy (SEM and TEM), X-ray diffraction (XRD), UV–vis diffuse reflectance spectroscopy (DRS) and photoluminescence (PL) emission spectra were used to characterize the structural and optical properties of the as-prepared catalysts. Active species trapping experiments demonstrated that additional sulfate radicals (·SO 4 - ) formed upon the addition of PS which could cooperate with superoxide radicals ( O 2 - ), holes (h + ) and hydroxyl radicals ( OH) to decompose NOR. Singlet oxygen ( 1 O 2 ) was also formed during the reaction and acted as an important active species. The degradation products of NOR were also identified and analyzed by using LC-MS technology , and the possible degradation mechanism and pathways were proposed and discussed. This work indicated that the shuttle-like CeO 2 modified g-C 3 N 4 coupled with PS displayed promising applications in the field of pharmaceutical wastewater purification.
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DOI
PubMed
高影响因子
CHEMOSPHERE
·
2022
·
IF 8.943
Yunjin Zhong,Haixiang Chen,Xiufang Chen,Bingying Zhang,Wenxing Chen,Wangyang Lu
As some of the most promising alternatives to traditional non-degradable materials, photodegradable materials have advantages of environmental benignity and rapid degradation under simple conditions. In this work, nontoxic TiO 2 and cost-effective g-C 3 N 4 have been compounded in a weight of 9:1 to form a photocatalytic additive with high activity. A 25 wt% loading of this photocatalytic additive has been incorporated into the polyacrylonitrile (PAN) by centrifugal electrospinning to prepare an abiotic degradable PAN material. Our results showed that the PAN chain could be almost fully degraded within 90 h in an aqueous medium under simulated sunlight in the absence of microorganisms . Product analysis implied that degradation of the PAN chain mainly involved the breaking of –CN and C–C bonds by radicals, followed by oxidation of terminal groups to carboxyl and gradual mineralization to CO 2 and H 2 O. This design strategy may provide new insight for the production and degradation mechanism of photodegradable polymer.
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PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2021
·
IF 7.312
Xueming Dang,Shuai Wu,Haiguang Zhang,Xie Quan,Huimin Zhao
A phosphorus (P) doped g-C 3 N 4 needle (PCNN) electrode with great photoelectrochemical (PEC) property is fabricated by a facile solid thermal melting approach. The proposed thermal melting method owns the advantages of low-cost, simple and easy operation, as only the solid mixing of melamine (C and N precursor) and triphenylphosphine oxide (P precursor) is needed in electrode preparation procedure. This method is further conducive to the formation of uniform film with doped heteroatom and unique microstructure on fluorine-doped tin oxide- coated glass (FTO). The PCNN photoelectrode holds a tip structure, which highly inhibits the recombination of photo-generated electron and hole. Particularly, the doped P in PCNN can further accelerate the photo-generated carrier separation and enhance the optical absorption property. As a result, the PCNN photoelectrode displays a five-fold enhancement of photocurrent density over pristine g-C 3 N 4 , reaching up to 127.4 µA cm - 2 at 1.23 V versus reversible hydrogen electrode (RHE), as well as good optical, chemical and physical stability. The PCNN photoelectrode further exhibits great property in PEC removal of pollutant in water. This study provides an effective fabrication method and opens new avenues for the significant improvement of g-C 3 N 4 based electrode in their various energy conversion and environmental application.
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高影响因子
NEW JOURNAL OF CHEMISTRY
·
2017
·Vol. 42
·期 1
·489-496
·
IF 3.269
Zengyu You,Qianhong Shen,Yuxuan Su,Yang Yu,Hui Wang,Tian Qin,Fang Zhang,Di Cheng,Hui Yang
A novel Z-scheme core–shell g-C3N4/MCNTs/BiOI heterojunction was successfully designed and fabricated through filling multi-walled carbon nanotubes (MCNTs) with g-C3N4, followed by the loading of BiOI on the outer surface of the MCNTs. The structure–property relationship was analyzed by X-ray diffraction (XRD), Fourier transform infrared spectra (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-vis diffuse reflectance spectra (DRS), photoluminescence spectra (PL), ESR probe tests and reactive species trapping measurements. The results show that the BiOI nanoparticles are uniformly loaded on the surface of the MCNTs which are fully filled by g-C3N4. The MCNTs connect the two semiconductors of g-C3N4 and BiOI, and serve as electron mediating conductors to promote the transfer of the photo-generated electrons, thereby constructing a Z-scheme heterojunction between g-C3N4 and BiOI. With this unique structure, enhanced visible-light photocatalytic activities are achieved because of the synergistic effect of light harvesting and improved separation efficiency of photo-generated carriers.
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高影响因子
Nanomaterials
·
2019
·Vol. 10
·期 1
·1
·
IF 4.034
Rui Geng,Juanjuan Yin,Jingxin Zhou,Tifeng Jiao,Yao Feng,Lexin Zhang,Yan Chen,Zhenhua Bai,Qiuming Peng
The construction of heterojunctions provides a promising strategy to improve photocatalytic hydrogen evolution. However, how to fabricate a nanoscale TiO2/g-C3N4heterostructure and hinder the aggregation of bulk g-C3N4using simple methods remains a challenge. In this work, we use a simple in situ construction method to design a heterojunction model based on molecular self-assembly, which uses a small molecule matrix for self-integration, including coordination donors (AgNO3), inorganic titanium source (Ti(SO4)2) and g-C3N4precursor (melamine). The self-assembled porous g-C3N4nanotube can hamper carrier aggregation and it provides numerous catalytic active sites, mainly via the coordination of Ag+ions. Meanwhile, the TiO2NPs are easily mineralized on the nanotube template in dispersive distribution to form a heterostructure via an N–Ti bond of protonation, which contributes to shortening the interfacial carrier transport, resulting in enhanced electron-hole pairs separation. Originating from all of the above synergistic effects, the obtained Ag/TiO2/g-C3N4heterogenous photocatalysts exhibit an enhanced H2evolution rate with excellent sustainability 20.6-fold-over pure g-C3N4. Our report provides a feasible and simple strategy to fabricate a nanoscale heterojunction incorporating g-C3N4, and has great potential in environmental protection and water splitting.Keywords:heterojunction;Ag/TiO2/g-C3N4;Co-assembly;hydrogen evolution
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PubMed
高影响因子
OPTICAL MATERIALS
·
2022
·
IF 3.754
Zhengdong Zhang,Xingyu Chen,Shanhua Chen,Qi Dong,Xinyi Zhang,Ao Jiang,Dafu Zhang,Yuli Di,Taishan Li
A Z-scheme TiO 2 /g-C 3 N 4 heterostructure system was used to activate peroxymonosulfate (PMS) for the photocatalytic degradation of Rhodamine B (RhB). The Z-scheme TiO 2 /g-C 3 N 4 heterojunction photocatalysts were successfully synthesized by using a simple impregnation method. The structure and surface morphology of the samples were characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), X-Ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The optical and electrochemical properties were characterized by UV–vis diffuse reflectance spectroscopy (DRS), photoluminescence (PL) electrochemical impedance spectroscopy (EIS).The results indicated that the Z-scheme heterojunction between TiO 2 and g-C 3 N 4 was successful established and the optimal photocatalytic activity was achieved when the mass ratio of TiO 2 to g-C 3 N 4 is 10:1. The degradation rate of RhB (20 mg/L, 50 mL) was 82.79% within 120 min simulated sunlight irradiation. After adding PMS to 10% TiO 2 /g-C 3 N 4 heterojunction photocatalysts , the reaction rate constant (k) of the TiO 2 /g-C 3 N 4 -PMS system is about 11.39 times as large as that with 10% TiO 2 /g-C 3 N 4 system. Moreover, the free radical trapping experiments results demonstrated that h + and SO 4 − · were the main active species in the TiO 2 /g-C 3 N 4 -PMS system.
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高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2020
·
IF 3.99
Hanjun Wu,Weijun Zhang,Huali Zhang,Yi Pan,Xiaofang Yang,Zhiquan Pan,Xuejun Yu,Dongsheng Wang
In this work, the novel graphitic carbon nitride (g-C 3 N 4 ) and porous polyimide (PI) supported calcined hydrotalcite-like compounds (g-C 3 N 4 @PI@CHTLcs) were synthesized by co-precipitation and hydrothermal synthesis method, and systematically characterized by physical and chemical methods . The composites showed layered structure and a high thermal stability, and performed well in adsorption of tetracycline (TL), 2, 4-dichlorophenol (DP) and glyphosate (GH). The action pH value was ranged from 7 to 9 for TL and GH, and 3–9 for DP, respectively. The adsorption of TL and DP by g-C 3 N 4 @PI@CHTLcs conforms to the pseudo-first-order kinetic model . While for GH, the kinetic data fit well with pseudo-second-order model, indicating chemical adsorption via electrostatic interaction mechanism. Freundlich isothermal could better describe the adsorption process of TL, DP and GH. The maximum adsorption amounts of TL, DP and GH based on Langmuir isotherm model at 298 K were 231.1, 185.05 and 177.34 mg g −1 , respectively. The adsorption processes of TL, DP and GH were all endothermic and spontaneous, and showed excellent repeatability and stability in regeneration experiments. Additionally, the presence of chloride ion and humic acid (HA) showed no obvious effects on the adsorption process of organic contaminants. The diffusion mechanism of TL, DP and GH on the adsorption process was liquid membrane control. The adsorption mechanism might be the ion exchange between the layers of hydrotalcite, and the surface complexation and hydrogen bonding between various groups of PI and organic contaminants. The research showed that g-C 3 N 4 @PI@CHTLcs was effective in treatment of water containing various organic pollutants .
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高影响因子
Journal of Environmental Chemical Engineering
·
2025
·Vol. 14
·期 1
·120879
·
IF 7.2
Chengzhao Liu,Tao Liu,Suhua Liu,Xiufang Zhang,Guanlong Wang
Recently, it was reported photocatalytic H 2 O 2 generation performed in biphasic system could significantly increase the H 2 O 2 yield. Aiming to further improve the H 2 O 2 yield, hydrophobic heterojunction of α-S and vacancy-rich g-C 3 N 4 (CNN) was constructed. H 2 O 2 production performance tests demonstrated the 0.2α-S/CNN composite achieved H 2 O 2 yields 1.72 and 1.99 times higher than pristine CNN and α-S, respectively. N-(C) 3 bonded nitrogen(N 3 C ) promoted oxygen activation, and heterojunction facilitated the separation of photogenerated holes and electrons. These contributed more effective photocatalytic synthesis of H 2 O 2 . The optimal 0.2α-S/CNN achieved a production rate of 2218 μmol g −1 , with an impressive apparent quantum yield (AQE) of 6.92 % under 455 nm monochromatic light, outperforming the state-of-the-art catalysts. The proposed mechanism suggested that photogenerated electrons migrated from α-S to CNN, reducing adsorbed O 2 to form •O 2 − radicals. These radicals subsequently reacted with water in the aqueous phase to generate H 2 O 2 via 2e − ORR. Due to the strong hydrophobicity of the catalyst, most •O 2 − radicals were generated in benzyl alcohol (BA) phase, while H 2 O 2 predominantly formed in the aqueous phase. This spatial separation delayed H 2 O 2 decomposition, facilitating its accumulation and enhancing overall yield.
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产品关联
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2019
·
IF 7.65
Ming Wu,Xin He,Binghua Jing,Teng Wang,Chengyin Wang,Yanlin Qin,Zhimin Ao,Shaobin Wang,Taicheng An
Graphite carbon nitride ( g -C 3 N 4 , CN) is considered as a promising semiconductor for environmental catalysis. However, pure CN can not meet the requirements for actual applications due to its high recombination rate of photogenerated electron-hole pairs and a relatively large band gap preventing full utilization of solar energy. In this work, we report synthesis of a novel carbon and defects co-modified g -C 3 N 4 (C x CN) by calcination of melamine activated by oxalic. This new catalyst C x CN has porous structure with much higher surface areas compared with pristine CN. UV–vis analysis and DFT calculations show that C x CN has a lower bandgap for enhancing visible light adsorption compared with CN. Photoluminescence (PL) and photoelectrochemical analyses show that C x CN has a low recombination rate of photogenerated electron-hole pairs, which improves the utilization of solar energy. As a result, C x CN samples show high efficiency for the degradation of bisphenol A (BPA) under visible light irradiation, where the best catalyst of C x CN (C 1.0 CN) samples shows about 22 times higher photocatalytic degradation rate than that of CN. Moreover, C 1.0 CN shows high mineralization rate and can degrade BPA into CO 2 and H 2 O by the generated active species, like superoxide radicals ( O 2 − ) and holes (h + ).
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高影响因子
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