APPLIED CATALYSIS B-ENVIRONMENTAL
·
2020
·
IF 16.683
Dandan Zhu,Qixing Zhou
In this work, nitrogen doped g-C 3 N 4 (NCN) with the extremely narrow band gap was prepared and applied for the photodegradation of phenols. Experiments and DFT (the density functional theory) computation identified that N-doping introduced in the g-C 3 N 4 matrix by substituting C atoms. DFT, PL (photoluminescence) spectra, optical property characteristic and PEC (photoelectrochemical) indicated that NCN possess extremely narrow band gap, efficient photogenerated carrier separation and the charge transfer, which enhanced the absorption of visible light and further promoted the photocatalytic activity. As a result, NCN(2:2) showed about twice higher photodegradation efficiencies and 3 times rate constant than pristine g-C 3 N 4 . The radical trapping experiments showed that •O 2 - radical and h + served as crucial active species during the whole photodegradation reaction. This work can provide a strategy to enhance the photocatalytic activity of photocatalysts via introduce foreign atoms in matrix.
研究领域:
材料科学
·
环境科学
·
理论化学
✓ 已验证
产品关联
DOI
高影响因子
ChemCatChem
·
2019
·Vol. 11
·期 22
·5562-5569
·
IF 4.495
Kuo Zhou,Bixian Chen,Xiaoting Zhou,Shimin Kang,Yongjun Xu,Jinjia Wei
Graphical Rane drops keep fallin’ : Cobalt proved to be the most efficient metal for furfurylamine synthesis by reductive amination of furfural with NH 3 and H 2 . Effect of metal nature on reductive amination was investigated with biomass-based furfural as a typical substrate. Among the tested heterogeneous metal catalysts, cobalt proved to be the most effective metal for the synthesis of the corresponding primary amine. Under a relatively mild reaction condition, 98.9 % yield of furfurylamine was obtained over Raney Co and it can be reused more than eight times without a significant decrease in the catalytic performance. By extensively studying the catalytic pathways and reaction mechanism, it is found that the selectivity to primary amine and secondary amine was governed by the relative rate of hydrogenolysis and hydrogenation of the Schiff base intermediate. The superiority of Raney Co in furfurylamine synthesis can be ascribed to its high efficiency on hydrogenolysis of the Schiff base intermediate and its low performance in the hydrogenation of the Schiff base, carbonyl group and furan ring. Furthermore, ammonia greatly promoted the catalytic hydrogenolysis of the Schiff base intermediate over Raney Co without clear deactivation of the metal active sites.
研究领域:
化学工程
·
生物质转化
·
催化科学
✓ 已验证
DOI
高影响因子
PROPELLANTS EXPLOSIVES PYROTECHNICS
·
2019
·Vol. 45
·期 3
·463-471
·
IF 1.634
Ming Zhang,Fengqi Zhao,Yanjing Yang,Ting An,Wengang Qu,Hui Li,Jiankan Zhang,Na Li
Three kinds of ferrates (NiFe 2 O 4 , ZnFe 2 O 4 and CoFe 2 O 4 ) were prepared via the facile solvothermal method and characterized using SEM, TEM, XRD, XPS, FT-IR and BET instruments. The NiFe 2 O 4 , CoFe 2 O 4 and ZnFe 2 O 4 particles possess hollow structure with average particle size of 70, 220 and 360 nm, respectively. The catalytic performance of the ferrates for AP thermal decomposition were studied using DSC and TG-DTG methods, and the decomposition mechanism of AP were suggested. The catalytic effects of different ferrates for AP thermal decomposition were significantly different. The CoFe 2 O 4 has the best catalytic activity, and the high thermal decomposition peak temperature ( T HDP ) and apparent activation energy ( E a ) of AP were decreased by 108.99 °C and 37.38 kJ mol −1 in the presence of CoFe 2 O 4 sample. Adding ferrates has no obvious influence on the gas-phase decomposition products of AP, but has a great influence on the energy barrier of high temperature decomposition of AP. The excellent catalytic activity of CoFe 2 O 4 is mainly attributed to the synergistic interaction between Fe and Co, which is conducive to the thermal decomposition of AP.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Catalysts
·
2020
·Vol. 11
·期 1
·24
·
IF 3.52
Juan Du,Jiaxin Zhang,Tingyu Yang,Renming Liu,Zhiyi Li,Dandan Wang,Tong Zhou,Yucun Liu,Chunbo Liu,Guangbo Che
The BiOI/NH2-MIL-125(Ti) composite photocatalyst with excellent photocatalytic performance was prepared by the solvothermal method. For the BiOI/NH2-MIL-125(Ti) (BNMT) system, the contents of NH2-MIL-125(Ti) in BNMT-4, BNMT-5, BNMT-7, BNMT-9, and BNMT-10 were 4 wt %, 5 wt %, 7 wt %, 9 wt %, and 10 wt %, respectively. XRD, XPS, SEM, and TEM characterizations indicated that BiOI/NH2-MIL-125(Ti) was successfully prepared. Brunauer, Emmett, and Teller (BET) and UV–vis diffuse reflectance spectra photoelectrochemical analysis indicated that BNMT-9 can make the specific surface area and photo absorption region larger than BiOI. In addition, the separation efficiency of photogenerated carriers was improved, and the recombination efficiency was reduced. The degradation percentages of Rhodamine B (RhB) and p-chlorophenol (P-CP) reached 99% and 90% over BNMT-9 under visible light irradiation. Additionally, the catalysts had high stability. The results of the active spices trapping experiments test indicated that h+was the main active species. The possible degradation mechanism was proposed.Keywords:photocatalysis;BiOI;NH2-MIL-125(Ti);organic pollutants
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS CHEMISTRY AND PHYSICS
·
2019
·
IF 2.781
Zhilin Li,Chongyue Jin,Chunmei Lv,Min Wang,Jin Kang,Shiyu Liu,Yuanhua Xie,Tong zhu
To further promote the visible-light photocatalytic efficiency of Bi 24 O 31 Cl 10 , g-C 3 N 4 /Eu(III) doped Bi 24 O 31 Cl 10 heterojunction composites (CN/Eu-BCO) were successfully synthesized via modified solution combustion and immersion-calcination method. The effects of Eu(III) dopants and g-C 3 N 4 coupling on the micro-structures and the photocatalytic efficiency of Bi 24 O 31 Cl 10 towards Rhodamine B (RhB) degradation were investigated in detail. The results displayed that Eu(III) doping and coupling with g-C 3 N 4 can largely promote the photocatalytic efficiency of Bi 24 O 31 Cl 10 . The photodegradation rate of RhB over 5CN/0.01Eu-BCO can reach to be 91.9% in 40 min, which was 8.46 folds of Bi 24 O 31 Cl 10 , 1.91 folds of 0.01Eu-BCO, and 1.72 folds of 5CN/BCO. The main radical species being responsible for RhB degradation were ● O 2 − and ● OH. Furthermore, 5CN/0.01Eu-BCO composite photocatalyst exhibited good reusability and stability.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2018
·Vol. 8
·期 25
·14056-14063
·
IF 2.936
Juanjuan Ma,Chaocun Zhou,Jinlin Long,Zhengxin Ding,Rusheng Yuan,Chao Xu
Graphene-based cocatalysts can improve the photocatalytic properties of semiconductors, but sometimes, they also function as barrier-like materials, influencing the photoactivity of composites. However, in a multi-cocatalyst system, less attention is paid to these negative effects of graphene on the performance of other cocatalysts. In this study, by adjusting the loading sequence of graphene and Ag cocatalyst on the surface of TiO2 spheres, the barrier effect of graphene sheets on Ag nanoparticles could be controlled effectively. As a result, these ternary composites with almost no Ag nanoparticles wrapped by graphene possessed improved properties for the photocatalytic reduction of nitro-aromatics as compared to those with some Ag nanoparticles covered by graphene. Furthermore, this phenomenon of barrier effect caused by graphene could be found in the control reaction with metal silver as the main catalyst; this indicated that by avoiding the possible negative influence of graphene on other cocatalysts, the properties of composites with graphene-containing multi cocatalysts could be further improved.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2018
·
IF 3.779
Yongmei Xia,Zuming He,Kejun Hu,Bin Tang,Jiangbin Su,Ya Liu,Xiaoping Li
In order to further improve the photocatalytic activity, Cu 2 O coupled with SrTiO 3 was for the first time constructed by introducing SrTiO 3 to Cu 2 O and synthesized via a two-step route. The obtained n-SrTiO 3 /p-Cu 2 O heterojunction photocatalysts were systematically characterized by XRD , XPS , SEM, UV–vis spectra, etc., showing that n-SrTiO 3 /p-Cu 2 O composites were formed by coupling SrTiO 3 submicroparticles with Cu 2 O cubic micrometer structure. Photocatalytic results demonstrated that the introduction of SrTiO 3 brought about significant enhancement of photocatalytic activity of Cu 2 O, which led to the fact that SrTiO 3 could serve as cocatalyst for the degradation of pollutant MB by forming p-n heterojunction to accelerate photo-generated charge carriers separation and migration and providing enriched active sites. The obtained n-SrTiO 3 /p-Cu 2 O heterojunction composites showed good stability and recyclability in the process of photo-degradation. Besides, the possible photocatalytic mechanism was proposed.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
Nanoscale
·
2016
·Vol. 8
·期 38
·16963-16968
·
IF 7.76
Guoqiang Zhang,Wenshuai Jiang,Shixin Hua,Haifeng Zhao,Ligong Zhang,Zaicheng Sun
Defects (Ti3+ or oxygen vacancies) have been demonstrated to promote the charge separation process in TiO2 based photocatalysts. Particularly, the bulk defects within a certain concentration can give a great enhancement for both light absorption and charge separation efficiency. In this report, we explored a one-step molten salts route to synthesize SrTiO3 nanocubes with bulk defects (Ti3+ doped) by using SrCO3 as a Sr source, and TiO2 and Ti powder as Ti sources. The amount of defects can be tuned by changing the molar ratio of Ti/TiO2. The corresponding bandgap of SrTiO3 can be changed from 3.29 to 2.73 eV with the increase of defects. X-ray diffraction and electron microscopy disclose that SrTiO3 is highly crystalline and has a cubic morphology. X-ray photoelectron spectroscopy and electron paramagnetic resonance indicate that the as-prepared SrTiO3 is close to the Ti3+ doped SrTiO3. Surface photovoltage spectroscopy (SPS) and field-induced SPS confirm that Ti3+ doping in the SrTiO3 turns it from an n-type semiconductor to p-type. The SrTiO3 with an optimal amount of defects exhibits highly enhanced photocatalytic performance. An excess amount of defects results in a weak SPS response and photocatalytic performance.
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2015
·
IF 7.435
Yue Chang,Kai Yu,Chenxi Zhang,Rui Li,Peiyuan Zhao,Lan-Lan Lou,Shuangxi Liu
Ag 3 PO 4 nanoparticles were firstly deposited into the three-dimensionally ordered macroporous WO 3 (3DOM-WO 3 ) with different pore sizes. The resulted Ag 3 PO 4 /3DOM-WO 3 composites were characterized by XRD, SEM, TEM and DR UV–vis. These composite photocatalysts showed extraordinarily excellent efficiencies in the visible light degradation of organic contaminants and water splitting for oxygen evolution, which were mainly due to the synergic effect of Ag 3 PO 4 and 3DOM-WO 3 as well as the periodic macroporous structure of 3DOM-WO 3 . Especially, the catalyst A5W5 with Ag 3 PO 4 :WO 3 mass ratio of 5:5 exhibited the highest catalytic activity, and complete degradation could be achieved within 4 min for phenol and three typical dyes investigated in this work. In addition, the slow photon effect in Ag 3 PO 4 /3DOM-WO 3 was demonstrated, and the pore size of 3DOM-WO 3 was found to have a significant influence on the catalytic performance. The catalyst A5W5(270) showed notably higher photocatalytic activity than A5W5(150) and A5W5 (420), which was mainly attributed to the exact overlap between the stop-band of 3DOM-WO 3 (270) and the electronic absorption band of Ag 3 PO 4 /3DOM-WO 3 composite. Moreover, these composite catalysts were very stable and could be recycled ten times without any loss in photocatalytic activity for RhB degradation. More excitingly, remarkably improved activity and durability were also obtained over Ag 3 PO 4 /3DOM-WO 3 in water splitting for oxygen evolution. According to the XPS and HRTEM characterizations of used catalyst, the enhanced durability was mainly attributed to the effective transfer of photogenerated electrons from Ag 3 PO 4 to 3DOM-WO 3 .
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of the Taiwan Institute of Chemical Engineers
·
2015
·
IF 3
Xia Cui,Yi Fan Zheng,Huan Zhou,Hao Yong Yin,Xu Chun Song
In this study, the Ag 3 PO 4 microcrystal was successfully prepared at different temperatures using precipitation and hydrothermal methods. The as-prepared products were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), UV–vis diffuse reflectance spectroscopy (UV–vis DRS) and so on. It was found that the synthesized temperature had some effects on the morphologies and photocurrent of Ag 3 PO 4 . As the synthesized temperature increased from 20 °C to 120 °C, the ratio of exposed (110) facets increased, which are the active photocatalysis facets in Ag 3 PO 4 crystals, along with a higher photocatalytic efficiency over RhB under visible light irradiation. And the Ag 3 PO 4 microcrystals synthesized at 120 °C exhibited the highest photocatalytic activities with the degradation ratio of RhB rising up to 97.83% in 6 min due to the high separation efficiency of electron and hole pairs. In addition, the main active species and their roles were investigated by adding scavengers (isopropyl alcohol and EDTA) during the photocatalytic degradation of RhB and a possible mechanism was discussed.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
NANO
·
2022
·
IF 1.438
Mengfan Wang,Wenbo Miao,Hongliang Xu,Chaoning Huang,Mingliang Li,Gang Shao,Hailong Wang,Hongxia Lu,Rui Zhang
g–C 3 N 4 nanosheets were first synthesized by calcining the mixture of hydrochloric acid-pretreated melamine and ammonium chloride. Then, by the aiding of solvothermal method and hydrofluoric acid as morphology modifier, 001-TiO 2 /g–C 3 N 4 (TCN-X, X = 5 , 3, 2, 1) nanocomposites were synthesized using g–C 3 N 4 nanosheets and tetrabutyl titanate, with the mass ratio of g–C 3 N 4 to TiO 2 was 5:1, 3:1, 2:1 and 1:1, respectively. The as-synthesized samples were characterized by X-ray diffraction, scanning electron microscope, transmission electron microscopy, Fourier transform infrared spectroscopy, nitrogen adsorption–desorption method, ultraviolet–visible diffuse reflectance spectrum, photoluminescence spectrum, etc. Their photocatalytic properties were evaluated under visible light irradiation with rhodamine B (RhB) as the target pollutant. The results reveal that the TCN-3 composites had a large specific surface area of 67.38 m 2 /g and consisted of g–C 3 N 4 nanosheets and anatase TiO 2 crystals about 10–20 nm in size. The (001) crystal planes of TiO 2 can be easily observed in TCN-X composites. All TiO 2 /g–C 3 N 4 composites exhibited excellent photocatalytic activity compared with the pure g–C 3 N 4 did. The photocatalytic property of TCN-X samples varied with the mass ratio of g–C 3 N 4 to TiO 2 , and TCN-3 presented the optimum photocatalytic performance. In total, 50 mg of TCN-3 completely degraded 50 mL and 100 mL of RhB solution (10 mg/L) in 15 min and 40 min, respectively. The reaction rate constant of TCN-3 was 6.7 times as large as that of pure g–C 3 N 4 . TCN-3 also presented outstanding activity for the photocatalytic degradation of the colorless tetracycline solution. The significant improvement in photocatalytic activity of TCN-3 was attributed to the evenly distribution of TiO 2 on g–C 3 N 4 , the enhanced specific surface area and the construction of 001-TiO 2 /g–C 3 N 4 heterojunction between the g–C 3 N 4 nanosheets and the (001) crystal planes of anatase TiO 2 , which greatly reduced the recombination rate of the photo-generated electron and hole.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2022
·
IF 14.224
Wen Xie,Guangyan Xu,Yan Zhang,Yunbo Yu,Hong He
A mesoporous LaCoO 3 perovskite oxide (LaCoO 3 -Meso) with three-dimensionally ordered helical interwoven structure was synthesized by a nano-casting method using KIT-6 as the hard template. The obtained LaCoO 3 -Meso with high surface area was tested for its catalytic performance in the NO x storage and reduction (NSR) reaction and compared with a sample synthesized by the conventional sol-gel method. The LaCoO 3 -Meso showed a significant advantage for NO x storage, with a NO x storage capacity 2 times higher than the regular sample. LaCoO 3 -Meso also exhibited improved NSR catalytic performance in the 150–450 °C temperature range, especially within 350–400 °C, where the NO x conversion was raised for 40%. The results of X-ray photoelectron spectroscopy and X-ray absorption fine structure measurements suggested the presence of a high concentration of oxygen defects on the LaCoO 3 -Meso surface. Further results provided by temperature programmed reduction and temperature programmed desorption indicated that the oxygen defects not only increase the amount of trapped NO x , but also improve the low-temperature redox performance of the catalyst. The lower stability of NO x species adsorbed on oxygen defects promotes the NO x release step in the NSR reaction and benefits the regeneration of storage sites.
研究领域:
材料科学
·
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）