APPLIED SURFACE SCIENCE
·
2022
·
IF 7.392
Ruiming Fang,Zhongqing Yang,Zukhra C. Kadirova,Ziqiang He,Ziqi Wang,Jingyu Ran,Li Zhang
The visible-light photocatalytic reduction of CO 2 becomes a vital breakthrough to alleviate the greenhouse effect and achieve carbon neutrality. In this paper, ultrathin g-C 3 N 4 nanosheets of 1.74 nm were constructed, and K + was successfully doped between layers. The yields of CO and CH 4 are 1.65 μmol·g −1 ·h −1 and 0.15 μmol·g −1 ·h −1 , which are 4.70 and 7.27 times higher than the original g-C 3 N 4 , respectively. The ultra-thin nano-lamellar structure shortens the carrier transmission distance, and the intercalation of K + not only promotes the electron transport between g-C 3 N 4 layers but also changes the original hybrid mode of the catalytic system, thus shortening the band gap and adjusting the energy band structure. In addition, the CO 2 adsorption center of the K + intercalated g-C 3 N 4 is transferred from the coordinated carbon atom to the center of the triazine unit, and the binding energy is obviously increased, which strengthens the CO 2 adsorption. Finally, through in-situ DRIFT characterization, it is speculated that the reaction enhancement mechanism is that the modified catalyst promotes the adsorption and activation of CO 2 , resulting in the production of more intermediates, especially more hydrocarbon intermediates, which is more conducive to the photocatalytic reduction of CO 2 .
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高影响因子
Frontiers in Chemistry
·
2022
·
IF 5.545
Huo Zhaohui,Liao Yanmin,He Yongyi,Zhang Yifan,Liao Xiaolin,Zhang Qitong,Wu Haojie,Shi Junjie,Wen Genglong,Su Haixia,Yao Suyang
Graphitic carbon nitride (g-C3N4) has shown to be a promising photocatalyst that, however, suffers from strong charge recombination and poor conductivity, while MXenes have shown to be perfect cocatalysts for the photocatalytic process but show poor stability. In this study, we successfully constructed 2D/2D heterojunctions of Fe-C3N4/Ti3C2 for the photocatalytic degradation of antibiotics. In this study, multilayer Ti3C2 was obtained by etching Ti3AlC2, and then Fe-C3N4/Ti3C2 photocatalyst was prepared by the one-pot microwave method and high-temperature calcination method. The synthesized samples were characterized by XRD, SEM, TEM, XPS, TGA, BET, DRS, PL, and other means. The photocatalytic degradation of tetracycline hydrochloride by Fe-C3N4/Ti3C2 was in accordance with the first-order reaction kinetics model, and the apparent rate constant k was 2.83, 2.06, and 1.77 times that of g-C3N4, Fe-C3N4, and g-C3N4/Ti3C2, respectively. Through the mechanism study, it was shown that the most active species in the reaction system was • O2−, while h+ and •OH had a relatively lower effect on the degradation system.
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高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2022
·
IF 14.224
Zhikun Huang,Haojie Yu,Li Wang,Xiaowei Liu,Shuning Ren,Jinyi Liu
Designing graphitic carbon nitride (CN) based heterostructured photocatalysts with high catalytic activity is highly desired for peroxymonosulfate (PMS) activation to degrade organic pollutants from water. Herein, a novel heterostructured composite (U-F@CN) consisting of ferrocene-modified Uio-66-NH 2 (U-F) and CN was synthesized. The U-F@CN exhibited superior photocatalytic performance to degrade bisphenol A (BPA) in the presence of PMS under visible light. The experimental results indicated that BPA could be removed entirely by U-F@CN within 60 min under visible light irradiation. In addition, the outstanding photocatalytic activity could be maintained at high level in a wide pH range, appropriate temperature region and natural water condition. Benefiting from the good chemical stability, outstanding optical property and in-situ generation of interfacial heterojunction of U-F@CN, the interfacial transport of photogenerated charges could follow the Z-scheme mechanism, which can accelerate the charge separation and transport to yield abundant reactive active species (ROS) to efficiently active PMS and under visible light. This work provides a novel approach to design CN-based heterostructured photocatalysts with high stability and superior photocatalytic activity for environmental remediation.
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高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2020
·
IF 4.65
Lei Cui,Siliang Liu,Fangke Wang,Jingyao Li,Yanhua Song,Ye Sheng,Haifeng Zou
In this work, uniform g-C 3 N 4 shells have grown on the surface of electrospinning TiO 2 nanofibers to form one dimensional core/shell structured TiO 2 /g-C 3 N 4 nanofibers by a facial melamine-involved vapor deposition approach. During the heat treatment process in a simple setup, the TiO 2 nanofibers served as supports to prevent the collapses and aggregations of g-C 3 N 4 while forming heterojunctions with g-C 3 N 4 at the interface. The as prepared heterogeneous TiO 2 /g-C 3 N 4 photocatalyst exhibited remarkably enhanced visible light photocatalytic activity for RhB degradation by maxing heterojunctions at the core/shell interface. The photodegradation reaction rate constant of the obtained heterojunction is 0.064 min −1 , which is 4.0 times that of pure g-C 3 N 4 (0.016 min −1 ). To reach higher RhB degradation efficiency (>90%), TiO 2 /g-C 3 N 4 shortened the irradiation time by 60 min compared with individual components (pure g-C 3 N 4 or TiO 2 nanofibers). The remarkably high photocatalytic performances are mainly ascribed to the synergetic effect of efficient photogenerated charge separation properties and decreased electron transfer resistance of the heterojunctions formed between g-C 3 N 4 and TiO 2 . We believe the proposed simple method and setup is an attractive strategy for constructing one dimensional g–C 3 N 4 –based nano-heterojunctions with excellent photocatalytic properties.
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高影响因子
Energy Storage Materials
·
2018
·
IF 0
Xu Huang,Xuezhang Xiao,Xuancheng Wang,Zhendong Yao,Chuntao Wang,Xiulin Fan,Lixin Chen
Li-Mg-B-H system with the composition of 2LiBH 4 -MgH 2 is one of the most promising reversible hydrogen storage materials because of the extremely high hydrogen storage capacity (11.5 wt%). Yet, sluggish kinetics with high desorption temperature (~ 400 °C) hindered its practical applications. Herein, a highly efficient catalyst of nanoNi@g-C 3 N 4 , comprised of transition metal nanocatalyst and carbon-based nonmetal material, was designed and fabricated to dramatically reduce its initial hydrogen desorption temperature to as low as ~105 °C, and eliminate induction period between the two dehydrogenation steps of 2LiBH 4 -MgH 2 by reducing the activation energy for the dehydrogenation of LiBH 4 from 200±6 to 126±7 kJ/mol. Multiple postmortem analyses revealed that the in situ formed MgNi 3 B 2 NPs and the H + defects on g-C 3 N 4 play the key role in synergically enhancing the hydrogen reversible desorption/absorption kinetics at low temperature: 1) in situ formed MgNi 3 B 2 acts as nucleation center of MgB 2 and leads to an excellent catalytic effect to accelerate the dehydrogenation kinetics of 2LiBH 4 -MgH 2 ; 2) the H + defects on g-C 3 N 4 , will interact with the H – in LiBH 4 to trigger the release of H 2 at low temperature and destabilize LiBH 4 and MgH 2 to form Li 3 N and Mg 3 N 2 respectively for the high electronegativity of N: 3) these in situ formed intermediates of Li 3 N and Mg 3 N 2 will be readily rehydrogenated as highly reversible Mg(NH 2 ) 2 and LiH. This novel transition metal and g-C 3 N 4 catalytic composites could provide alternative insights into designing nanosized catalytic hydrogen storage system with low desorption temperature and high capacity for hydrogen-fueled applications.
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SEPARATION AND PURIFICATION TECHNOLOGY
·
2019
·
IF 5.107
Yuqi Cui,Li-chao Nengzi,Jianfeng Gou,Yan Huang,Bo Li,Xiuwen Cheng
Z-scheme heterojunction photocatalyst can simultaneously reduce the recombination of photo-generated electron-hole pairs and preserve its outstanding redox ability during the process of photocatalytic reaction. In this study, Z-scheme MIL-53(Fe)/α-Bi 2 O 3 /g-C 3 N 4 photocatalyst was successfully fabricated via an accessible method and comprehensive characterized by XRD, FT-IR, SEM, TEM, XPS, N 2 adsorption-desorption isotherms, UV–vis diffuse reflection spectroscopy and photoelectrochemical analysis. The as-obtained MIL-53(Fe)/α-Bi 2 O 3 /g-C 3 N 4 composite exhibited superior photocatalytic activity for amino black 10B degradation than that of pure g-C 3 N 4 , α-Bi 2 O 3 , MIL-53(Fe) and α-Bi 2 O 3 /g-C 3 N 4 binary composite under visible light irradiation and the photodegradation rate would achieve the maximum when the mass fraction of MIL-53(Fe) was 32% in ternary composite. The enhanced photocatalytic performance of MIL-53(Fe)/α-Bi 2 O 3 /g-C 3 N 4 ternary composite could be mainly ascribed to improved visible light absorption range and the construction of an effective interfacial heterojunction driven by direct solid-state dual Z-scheme mechanism, which significantly facilitates the separation and transfer of photo-generated charge carriers. Eventually, the as-prepared ternary composite was confirmed to have prominent stability and reusability after consecutive 4 recycling run.
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高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2021
·
IF 4.539
Chunyan Zhang,Zhendong Fu,Feng Hong,Ge Pang,Tengri Dong,Yunxiao Zhang,Guixia Liu,Xiangting Dong,Jinxian Wang
Broad spectrum response photocatalyst is crucial for making full use of sunlight and widely used in efficient photocatalytic degradation of organic dyes. In this work, upconversion luminescence boosted broadband photocatalysts based on BiF 3 :Yb 3+ , Er 3+ nanoparticles (BFY) and the carbon nitride doped with various masses of barbituric acid (CNB x ) semiconductor materials (BFY/CNB x ) were successfully designed and produced for photocatalysis in UV–Vis–NIR region. Compared with pure g-C 3 N 4 , BFY/CNB 0.5 composites have better photocatalytic performance attributed to the utilization of broadband spectrum energy and effective charge separation. After 30 min illumination by visible light , photodegradation efficiency of RhB reaches about 99.4% by using BFY-2/CNB 0.5 . A plot of C/C 0 versus time indicates that the BFY-2/CNB 0.5 can degrade about 64.7% of RhB in 80 min by NIR irradiation. Under simulated solar light, the sample of BFY-2/CNB 0.5 reaches a maximum degradation efficiency of 98.0% within 15 min. The strengthened photocatalytic activity is due to the synergistic effect of CNB 0.5 and upconversion materials. The active species utilized in the degradation process were examined using capture experiments. After four continuous photocatalytic cycles, about 94.0% of RhB solution is degraded. The photocatalytic mechanism of the composite photocatalysts is also analyzed in detail. The results indicate that the prepared BFY/CNB 0.5 photocatalysts have good prospects in the field of environmental remediation.
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高影响因子
Journal of Materials Chemistry A
·
2021
·Vol. 9
·期 39
·22373-22379
·
IF 12.732
Xiao-Long Pu,Xue-Chun Yang,Shan-Shan Liang,Wenzhong Wang,Jing-Tai Zhao,Zhi-Jun Zhang
An N-modified carbon dots/graphitic carbon nitride (NCDs/g-C3N4) aerogel was successfully prepared by simple electrostatic self-assembly of NCDs and g-C3N4 nanosheets without any harmful solvents or cross-linking agents. The prepared aerogel has a larger specific surface area compared to pure g-C3N4. As the NCD content increased, the NCDs/g-C3N4 aerogel exhibited a wider visible spectral response range and higher photo-generated carrier separation efficiency. It is of note that the hydrogen evolution rate (HER) of the NCDs/g-C3N4 aerogel can reach up to 13 499 μmol h−1 g−1, which is 1.6 times that of pure g-C3N4, because of the advantages of the 3D aerogel structure and the effect of NCDs on photocatalytic activity. The design realizes the control of the morphology of g-C3N4 by NCDs and provides a new strategy for the design of aerogels for highly efficient photocatalysis.
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高影响因子
Polymers
·
2020
·Vol. 12
·期 1
·76
·
IF 3.426
Tingting Wang,Bo Song,Li Wang
In this study, graphitic carbon nitride (g-C3N4) as a novel filler was used for fabricating epoxy nanocomposites. The static mechanical, dynamic thermal-mechanical properties and thermostability of as-prepared g-C3N4/epoxy nanocomposites were significantly ameliorated compared with that of the pure epoxy matrix. The tensile modulus and flexural modulus of g-C3N4/epoxy nanocomposites increased by 31.81% and 28.28%, respectively. Meanwhile, the tensile and flexural strength was also improved by 16.02% and 12.67%, respectively. The g-C3N4/epoxy nanocomposites exhibited an increased storage modulus and glass transition temperature. The markedly improved mechanical and viscoelasticity properties were attributed to the stronger interfacial interaction caused by enlarged contact area and increased chemical bonding, and enhanced mechanical interlocking on the interface. The loss factor of epoxy nanocomposites also raised by 40% due to the comprehensive effect of frication caused by the relative slip between nanosheets, micro-constrained layer damping structure and the reversible cycle of breakage and re-established of the hydrogen bond. Meanwhile, the 10% weightlessness temperature (Tinitial), semi weightlessness temperature (Thalf) of g-C3N4/epoxy nanocomposites have increased by about 15 °C and 14 °C, respectively.
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高影响因子
Journal of Cleaner Production
·
2020
·
IF 7.246
Jianhua Hou,Ting Jiang,Xiaozhi Wang,Geshan Zhang,Ji-Jun Zou,Chuanbao Cao
It is still challenging to adjust the desired structure and heterojunction interface of photocatalytic materials by a facile and efficient strategy. In this manuscript, variable dimensional structured BiOI with surface oxygen vacancies (OVs) were prepared via an in-situ growth on mesoporous g-C 3 N 4 nanosheets through one-pot synthesis at room temperature, which possesses the p-n heterojunction required for the high-performance photocatalysis . By reducing the amount of the precursor of BiOI during the reaction, the morphology of BiOI gradually changed from 3D microspheres to 2D nanosheets and even 0D nanoparticles , which were conjugated with ultrathin g-C 3 N 4 nanosheets forming the composites with 2D/3D, 2D/2D, and 2D/0D structure, respectively. The catalyst with the best performance was determined to be the g-C 3 N 4 /BiOI with 2D/2D structure, which provides a larger contact surface, appropriate bandgap, and the higher utilization of visible light. The synergies between heterostructure and OVs can promote both the production and the separation of electron-hole effectively, and hence producing more oxidizing • O 2 − and h + with the energy input. Thereby, under visible light, the optimized combination of g-C 3 N 4 /BiOI heterojunction can exhibit the outstanding photocatalytic performance of degrading 99% rhodamine B within 2 h, which was 2.6 and 12.8 times faster than pure g-C 3 N 4 and pure BiOI, respectively. In addition, our work provides a feasible and adjustable approach to regulate the structure and heterojunction interface of photocatalysts as well as the discussion about the variable dimensional structure-activity relationship in photocatalysis .
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高影响因子
APPLIED SURFACE SCIENCE
·
2017
·
IF 3.387
Liang-pei Hou,Rong-xiang Zhao,Xiu-ping Li,Xiao-han Gao
A series of catalysts of composition X -MoO 2 /g-C 3 N 4 ( X = 0, 0.5, 1, 3, 5 wt.%) were successfully synthesized by calcination of a mixture of (NH 4 ) 6 Mo 7 O 24 ·4H 2 O and g-C 3 N 4 . Oxidative desulfurization experiments were conducted using X -MoO 2 /g-C 3 N 4 as a catalyst, H 2 O 2 as an oxidant, and ionic liquids (ILs) as extraction agents. Catalysts were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier-transform infrared (FT-IR), scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS), and Brunauer-Emmett-Teller analysis (BET). Characterization results suggested that MoO 2 was present in the catalyst and its crystallinity improved with increased Mo-loading. The catalysts had a larger specific surface area due to the presence of MoO 2 dispersed on g-C 3 N 4 . Experimental results showed that 3%-MoO 2 /g-C 3 N 4 had the highest catalytic activity among all the catalysts tested. A desulfurization rate of 96.0% was achieved under optimal conditions. Through gas chromatography-mass spectrometry (GC–MS) analysis, it was shown that dibenzothoiphene sulfone was the sole product of the oxidation desulfurization reaction. An apparent activation energy of 61.1 kJ/mol was estimated based on Arrhenius equation. The activity of 3%-MoO 2 /g-C 3 N 4 slightly decreased after six runs. A possible mechanism for the reaction has been proposed.
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高影响因子
International Journal of Environmental Research and Public Health
·
2022
·Vol. 19
·期 24
·16651
·
IF 4.614
Nan Yang,Zhihan Zhang,Shicheng Zhang,Liting Chen,Jia Zhu,Jingsi Gao
In order to improve the catalytic activity and recycling performance of semiconductor activators, and improve the activation pathway of persulfate, graphitic carbon nitride (g-C3N4) was prepared by calcining melamine, and a composite activator Ag2O/g-C3N4based on g-C3N4supported metal oxide was prepared using a precipitation method. The morphology, structure, and basic properties of the composites were characterized using SEM, XRD, FT-IR and XPS. The activation efficiency of the Ag2O/g-C3N4composite activator on peroxodisulfate (PDS) was explored. The results showed that Ag2O in the composite activator was highly dispersed on the surface of g-C3N4and did not change the molecular structure of g-C3N4significantly. Under different activation systems, the degradation process of MO was best fitted under the pseudo-second-order reaction kinetic model, compared to the separate g-C3N4or Ag2O activated PDS systems; the activation of the PDS system with Ag2O/g-C3N4had the best effect on MO degradation; and the composite activator Ag2O/g-C3N4showed better activation performance. Under the conditions that the mass combined ratio of Ag2O in the activator was 12%, the initial concentration of PDS was 4 mmol/L, the initial concentration of the activator was 1.25 g/L, and the initial pH was 3, the degradation degree of MO reached 99.4% after 40 min reaction. The free radical quenching experiment proved that the active substances that could degrade MO in the system were SO4−· and ·OH, and the effect of SO4−· was greater than that of ·OH. The degradation degree of MO in the reaction system remained above 80% after four cycles of use, and the crystal structure of Ag2O/g-C3N4did not change significantly before and after the reaction. The above results show that Ag2O/g-C3N4is an efficient and stable composite activator with good application potential in the treatment of dye wastewater by activating PDS.
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高影响因子
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