CHEMICAL ENGINEERING SCIENCE
·
2023
·
IF 4.7
Fan Fu,Jian Yang,Hao Xu,Yang Li,Shaobo Cao,Kang Da,Wenting Chen,Ximei Fan
Doping or constructing heterojunctions by coupling with other semiconductors are effective methods to improve the photocatalytic performance of graphitic carbon nitride (g-C 3 N 4 ) in toluene degradation. Herein, thermally condensed synthesized K-doped g-C 3 N 4 (KCN) is coupled with BiOCl via a hydrothermal method, and KCN/BOC heterostructures are obtained. The optimal KCN 1 /BOC heterojunction exhibits approximately 85% removal of toluene after 150 min irradiation under simulated solar light, which is 12.4 and 9.6 times higher than those of g-C 3 N 4 and BiOCl, respectively. The superior performance of KOH-modified g-C 3 N 4 is attributed to the electron transfer channels formed by the insertion of K + into the g-C 3 N 4 layers, which facilitate efficient charge separation and rapid electron transfer. Furthermore, the KCN/BOC heterostructure with the Z-scheme further improves the surface charge separation efficiency, which plays a critical role in the photocatalytic process. This work provides a facile and promising strategy for dual-strategy modification of g-C 3 N 4 to enhance photocatalytic degradation activity.
研究领域:
材料科学
·
环境科学
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产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF ENERGY RESEARCH
·
2022
·Vol. 46
·期 11
·15376-15386
·
IF 4.672
Tianle Li,Siddig Abuelgasim,Wenju Wang,Yupeng Xiao,Chenlong Liu,Yaoyao Ying,Dong Liu
Summary Soot particulate emitting from diesel engines are serious to both human health and environment. Efficient catalyst is vital in diesel particulate filter technology to decrease soot oxidation temperature. Cu 1−x K x Fe 2 O 4 (x = 0, 0.05, 0.1, and 0.15) catalysts are synthesized and analyzed with XRD, Raman, BET, SEM, TEM, TG, EDS, XPS, catalytic activity tests, and kinetic analysis. The results suggests that many factors affect the catalytic activity, and the contents of oxygen vacancies are dominant. A large amount of oxygen vacancies which facilitate to the soot oxidation are created with the assistance of K + , and they increase with the increasing doping contents. Excessive surface concentration of K + may lead to the partially covering of active sites of the catalysts. Therefore, Cu 0.9 K 0.1 Fe 2 O 4 catalyst exhibits the best catalytic activity in soot oxidation, which decreases the T max of soot by 279°C. This decrease makes it highly promising for application in diesel particulate filter.
研究领域:
环境科学
·
催化化学
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2016
·
IF 2.758
R.Q. Yin,P. Zheng,J.C. Wang,B.W. Dai,L.M. Zheng,J. Du,L. Zheng,J.X. Deng,K.X. Song,H.B. Qin
Lead-free piezoelectric ceramics Sr 1.85 Ca 0.15 Na 1− x K x Nb 5 O 15 (0.00≤ x ≤0.40) were prepared using the conventional solid state reaction method. The structural, dielectric and piezoelectric properties were systematically studied. All the ceramics are single orthorhombic tungsten bronze phase at room temperature, and the lattice constants increase with K + content. The dielectric spectra of each composition had two dielectric anomalies. The Curie temperature T c gradually decreases from 291 °C to 266 °C as x increase from 0.00 to 0.40, and the transition temperature T s from orthorhombic phase to tetragonal phase increases from 39 °C to 109 °C. With increasing K + contents, the piezoelectric coefficient d 33 increases rapidly initially, reaches a maximum and then gradually decreases. The highest piezoelectric performance was obtained at x =0.10, with piezoelectric coefficient d 33 =114 pC/N. Mechanisms that lead to the enhancement of d 33 were discussed from the viewpoint of polarization and crystal structure.
研究领域:
材料科学
·
物理学
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产品关联
DOI
高影响因子
Journal of Materials Chemistry A
·
2020
·Vol. 8
·期 14
·6785-6794
·
IF 11.301
Wenbin Wang,Zhu Shu,Jun Zhou,Dawei Meng,Zhengliang Zhao,Tiantian Li
Upgrading the melon-based bulk polymeric carbon nitride (PCN) into tri-s-triazine-based crystalline PCN has been proved effective and crucial to improve its intrinsic photocatalytic activity. Currently, facilitating the synthesis process of crystalline PCN and further optimizing its structure are challenging and have attracted increasing attentions. This work realized the facile one-step synthesis of K+-doped tri-s-triazine-based crystalline PCN with delicate box-shapes (KCCNB-x), by heating melamine with KCl using a vapor-deposition approach. KCCNB-30 demonstrated greatly boosted visible-light photocatalytic H2 evolution (HER) activity which is 33 times that of BCN. This benefits mainly from the facilitated photo-exciton transfer in the tri-s-triazine-based crystalline framework as well as the further enhanced light absorption in the box shape of KCCNB-30. Additionally, the versatility of this strategy was proved via successfully synthesizing Na+-doped tri-s-triazine-based crystalline PCN with box-shapes.
研究领域:
材料科学
·
能源化学
·
纳米技术
✓ 已验证
DOI
高影响因子
Advanced Materials Interfaces
·
2022
·Vol. 9
·期 6
·2102331
·
IF 6.389
Beibei Zong,Jianguo Deng,Qing Sun,Zizhao Zhang,Xiangxin Meng,Bo Shen,Bonan Kang,S. Ravi P. Silva,Geyu Lu
After perovskite became a star material, research on perovskite solar cells (PSCs) became a hot topic and developed rapidly. Electron transport layers (ETLs) with high mobility, low-defect state, and suitable energy level arrangement dominate the development of planar heterojunction PSCs. In this work, the K + and Cs + doped composite SnO 2 ETL ( x mg KC-SnO 2 ) by a continuous spin-coating of the x mg Cs + @KOH and SnO 2 aqueous solution shows a substantial improvement in carries extraction, transport and collection properties, leading to the increased fill factor (FF) from 72.48% to 81.00% of the planar heterojunction PSCs, and finally the champion device average efficiency is 21.62%. Moreover, this work improves the interface contacts between ETL/Perovskite, as it reduces energy disorder and simultaneously promotes electron transport, charge extraction at the interface, improve energy level alignment and quasi-Fermi level splitting, and decreased resistance for charge transfer in the device. In conclusion, this simple and effective method of improving the FF value provides a certain shortcut to the performance of plane heterogeneous perovskite devices.
研究领域:
材料科学
·
能源技术
✓ 已验证
产品关联
DOI
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2022
·
IF 10.753
Tongtong Wang,Jiyong Zheng,Jinjun Cai,Qiangqiang Liu,Xianxia Zhang
To improve the performance of graphitic carbon nitride (g-C 3 N 4 ), a hotly researched metal-free photocatalyst, for better application in the efficient removal of organic pollutants, adsorption synergistically enhanced photocatalysis mechanism was thoroughly explored. Based on KOH pore-forming activated biochar (ACB) and K + doped g-C 3 N 4 (K-gC 3 N 4 ), the novel activated biochar-based K-gC 3 N 4 composite (ACB-K-gC 3 N 4 ) was synthesized via the innovative ultrasonic-milling method. Rhodamine B (RhB), tetracycline (TC), norfloxacin (NOR), and chloramphenicol (CAP) were selected as target pollutants, and the effects of environmental factors, recycling and actual wastewater tests, disinfection effects, and various enhancement strategies were investigated. The results showed that K-gC 3 N 4 was successfully composited with ACB by various characterizations, where the loading mass ratio of 1:2 exhibited the best performance. ACB-K-gC 3 N 4 possessed a larger specific surface area, richer functional groups, suitable band gap (2.29 eV), and broader visible light absorption (~716 nm) than K-gC 3 N 4 . ACB-K-gC 3 N 4 presented effective removal efficiency over K-gC 3 N 4 for four pollutants, in which the removal efficiency of RhB reached 93.26%, and the degradation rate constant of 0.0119 min −1 was four times higher than K-gC 3 N 4 (0.0029 min −1 ). Moreover, ACB-K-gC 3 N 4 was superior to K-gC 3 N 4 in disinfecting S. aureus and E. coli , with a sterilization rate of exceeding 90% for 12 h. The photodegradation activity was dominated by · O 2 − , h + , and · OH, and the mechanisms involved in the three stages. This was attributed to the unique structure and surface properties (defects and persistent free radicals) of ACB, as evidenced by improved adsorption stage and transfer of degradation intermediates, facilitated the generation of active species, accelerated migration of photogenerated electrons, and inhibited photogenerated carriers recombination by the heterojunction . The good reusability and stability, enhancement strategies (blowing air and heating), and satisfactory feasibility for actual wastewater allow ACB-K-gC 3 N 4 possible to promote high-concentration wastewater treatment and disinfection.
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
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Wen Lu,Aimin Wang,Yanyu Zhang,Songyu Ren,Zhongguo Zhang
In this work, an innovative strategy combining vacuum ultraviolet (VUV) and K doping graphite carbon nitride (K-g-C 3 N 4 ) was proposed for antibiotic removal in aqueous. The properties of K-g-C 3 N 4 were systematically characterized by XRD, FT-IR, BET, SEM, UV-vis DRS, and XPS, showing that K-g-C 3 N 4 possessed a larger specific surface and richer functional groups than g-C 3 N 4 . The catalytic efficiency of K-g-C 3 N 4 was investigated for the trimethoprim (TMP) removal under VUV irradiation. Compared with UVC photolysis, VUV photolysis, UVC/g-C 3 N 4 , VUV/g-C 3 N 4 , and UVC/K-g-C 3 N 4 processes, VUV/K-g-C 3 N 4 enhanced the pseudo-first-order reaction rate constant of TMP removal by 2.0–19.7 times and the mineralization rate by 9.0%-38.2%. Electron paramagnetic resonance results and quenching experiments validated that O 2 •- , • OH, 1 O 2 , h + , and e - were engaged in the VUV/K-g-C 3 N 4 process. The fluorescent spectra of O 2 •- -substituted and • OH-substituted products revealed that the K-g-C 3 N 4 greatly enhanced the quantity of O 2 •- and • OH during VUV irradiation. The VUV/K-g-C 3 N 4 system produced marginally more H 2 O 2 and • OH than the UVC/K-g-C 3 N 4 system, confirming that K-g-C 3 N 4 predominantly utilized the UVC and other ultraviolet–visible light emitted by the VUV lamp, with VUV having a minor effect. Furthermore, K-g-C 3 N 4 had exceptional stability and reusability, efficiently degrading various contaminants under VUV irradiation. This work offered a comprehensive insight into VUV/K-g-C 3 N 4 process as a novel approach for antibiotic removal from water.
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
LANGMUIR
·
2021
·
IF 3.882
Binyao Liu,Xiaoqin Nie,Yi Tang,Shan Yang,Liang Bian,Faqin Dong,Huichao He,Yong Zhou,Kun Liu
The thermal-condensation method is widely used for the synthesis of K-doped g-C3N4 photocatalysts, but the presence of organic byproducts in the resultant products is often overlooked in previous reports. Here, we demonstrated the universal presence of organic byproducts in K-doped g-C3N4 synthesized by typical thermal condensation of KOH/melamine, KOH/dicyandiamide, or KOH/urea. Taking the K-doped g-C3N4 photocatalysis for the degradation of dimethyl phthalate as an example, the negative influence of the organic byproducts on K-doped g-C3N4 photocatalysis was confirmed. Specifically, the organic byproducts can be gradually dissolved into the photocatalytic system of K-doped g-C3N4 as new and stable pollutants. Based on the solubility investigations on the byproducts in several solvents, hot-water washing was demonstrated to be a relatively effective approach to remove the organic byproducts from K-doped g-C3N4. The formation of organic byproducts during the synthesis of K-doped g-C3N4 could be ascribed to the fact that the presence of K salts in melamine, dicyandiamide, or urea molecules results in their insufficient thermal condensation into expected g-C3N4. The present work provides objective information about the K-doped g-C3N4 photocatalysts and reminds researchers about the influence of the organic byproducts on the applications of the other impurity-doped g-C3N4 photocatalysts.
研究领域:
材料化学
·
环境催化
·
光催化
·
纳米材料
·
污染物降解
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2017
·Vol. 52
·期 19
·11569-11579
·
IF 2.599
Lan Jin-Le,Ma Wenqiang,Deng Chengjie,Ren Guang-Kun,Lin Yuan-Hua,Yang Xiaoping
A series of K-doped Bi 1− x
K
x
CuSeO (0 ≤ x ≤ 0.10) compounds were prepared by combustion synthesis combined with spark plasma sintering method. Phase composition and microstructure analysis indicate almost single BiCuSeO phase in low doping level, while phase separation appears in heavy doping level. The thermoelectric properties of the Bi 1− x
K
x
CuSeO compounds have been measured in the temperature range of 323–823 K. The electrical conductivity is greatly enhanced by almost three times from 8.70 to 26.2 S/cm at 323 K by the substitution of Bi with K due to the large decrease of the activation energy. The overall thermal conductivity decreases significantly due to the strong point defect scattering by K doping and possibly enhanced interface scattering on the secondary phase. The maximum ZT reaches 0.6 at 823 K for the sample of x = 0.02, which is about 50% higher than that of the pristine sample. Our work offers a fast and more efficient approach for the fabrication of BiCuSeO-based materials.
研究领域:
材料科学
·
无机非金属材料
·
热电材料
·
固态化学
·
纳米复合材料
✓ 已验证
DOI
高影响因子
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
·
2020
·
IF 3.085
Junnan Qu,Yi Du,Yibing Feng,Jianyong Wang,Bo He,Minxing Du,Yang Liu,Nan Jiang
A visible-light-responsive hybrid photocatalyst , K-doped g-C 3 N 4 /BiOBr, has been synthesized by K-doped g-C 3 N 4 (K–CN) and BiOBr. The property of photocatalysts was characterized by XRD , FT-IR, TEM, SEM , DRS , PL , EIS and HPLC. The photocatalytic activity of K-doped g-C 3 N 4 /BiOBr was evaluated by degradation of Rhodamine B (RhB) and tetracycline hydrochloride under visible-light irradiation. The K-doped g-C 3 N 4 /BiOBr hybrid photocatalyst which contains K–CN with mass fraction of 20% (20K–CN/BiOBr) shows the best degradation efficiency of RhB. The degradation efficiency of RhB (20 mg/L) can be achieved to 99% and the degradation efficiency of tetracycline hydrochloride by BiOBr decreased with the increase of K-doped g-C 3 N 4 doping. The results of photocurrent and EIS assumed that the tight coupling between K–CN and BiOBr can enhance the separating efficiency of photo-generated carrier. In addition, the capture experiment proof that h + is the primary active substance in the system of reaction and ·OH is the auxiliary active substance. After five degradation experiments, the efficiency of the degradation of Rhodamine B by the sample can still reach 90%, which proves that the samples are stable. A new and efficient method is provided in this work to solve the pollution of organic dyes and antibiotics.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
Materials Today Communications
·
2025
·
IF 4.5
Jiwei Yao,Weijun Ren,Qing Guo,Ziqi Guan,Dongliang Zhao,Jun He,Bing Li
The development of ultra-low-temperature magnetocaloric materials (MCMs) is crucial for advanced cryogenic refrigeration technologies. Rare-earth fluorides exhibit promising magnetocaloric properties, but the high magnetic ordering temperatures ( T 0 ) limit their performance below 2 K. Single-phase KLnF 4 (Ln = Tb, Dy, Ho, Er, Tm) compounds with a trigonal structure were successfully synthesized by introducing the diamagnetic K⁺ ions into LnF 3 via solid-state sintering. Structural analysis confirms that the K⁺ incorporation increases the distance between Ln 3+ ions, suppressing dipolar interactions and reducing T 0 to below 2 K. Notably, KHoF 4 exhibits a 16.5 % higher magnetic entropy change (-∆ S M ) than HoF 3 , attributed to the lower magnetic anisotropy of the trigonal KHoF 4 with higher symmetry. The effects of these two aspects overcome the negative impact caused by the decrease of the magnetic ion concentration. These findings demonstrate that K⁺ incorporation is a dual-functional strategy for simultaneously modulating transition temperatures and magnetocaloric performance of rare-earth fluorides. This work provides a scalable approach to designing ultra-low-temperature MCMs with various refrigeration windows.
研究领域:
材料科学
·
凝聚态物理
·
低温工程
·
磁性材料
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Ou Hai,Peng Li,Jian Li,Bin Qin,Tong Li,Zechuan Qi,Qiang Ren,Yuanting Wu
ABSTRACT A new type of lead-free perovskite Cs 3 Bi 2 Br 9 nanocrystal (NCs) was synthesized by thermal injection method at 190 °C, according to X-ray diffraction and theoretical analysis, the Cs 3 Bi 2 Br 9 NCs belongs to the monoclinic system C12/c1. We report for the first time that the luminescence intensity of broad-peak-emitting Cs 3 Bi 2 Br 9 is significantly improved by doping with K + , and the full-width at half maximum (FWHM) of sample Cs 3 Bi 2 Br 9 :0.2K + is 124 nm. Herein, the stability of Cs 3 Bi 2 Br 9 :xK was monitored and found to have excellent environmental stability, thermal stability, and photostability. In addition, Cs 3 Bi 2 Br 9 :0.2K was coated outside Sr 2 MgSi 2 O 7 :Eu 2+ ,Dy 3+ (SMS) to form a core-shell structure composite material Cs 3 Bi 2 Br 9 :0.2K + /SMS@SiO 2 and achieved fine tuning of the afterglow color. This work increases the luminescence intensity of Cs 3 Bi 2 Br 9 by ion doping and exhibits excellent stability, in addition to the cladding of lead-free perovskites with long afterglow materials provides a new application strategy for lead-free perovskites.
研究领域:
材料科学
·
光学
·
化学
✓ 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）