ACS Sustainable Chemistry & Engineering
·
2019
·
IF 6.97
Yanyan Liu,Zhaorui Min,Jianchun Jiang,Kang Sun,Jie Gao,Yuan Shang,Baojun Li
Construction of tightly bonded interfaces is an indispensable and critical strategy for promoting the catalytic performances of composite structures. In this study, a novel two-dimensional (2D) composite was successfully fabricated through the simultaneous formation of cobalt sulfide (Co9S8) nanosheets and N-, S-doped graphene (NSG). Cobalt–thiourea with graphene oxide was used as the precursor for a low-temperature and one-step pyrolysis. The optimal Co9S8/NSG-220 achieved a small onset overpotential of 147 mV, a low Tafel slope of 97 mV·dec–1, superior long-term durability after 16 h, and high faradic efficiency (nearly 100%) for the hydrogen evolution reaction (HER) in an acid electrolyte. The tightly bound sheet-on-sheet structure significantly enhanced the intrinsic catalytic activity due to the mutual activation effects between the components. Based on the experimental investigation and density functional theory calculations, the mutual activation effects induced by the electron transfer across the active interface constructed between NSG and Co9S8 was proposed as a key factor in the origin of superior catalytic activity. The HER catalytic activities were further improved by doping Mo into the composites. This design inspires new thoughts for exploring 2D composites prepared using molecular precursors with controlled compositions and morphologies as performance-enhanced electrocatalysts for future sustainable clean energy conversion.
研究领域:
材料科学
·
电化学
·
能量转换
·
纳米技术
·
催化
✓ 已验证
DOI
高影响因子
CARBON
·
2018
·
IF 7.082
Hua Xiao,Pu Xie,Shou Ji Qiu,Min Zhi Rong,Ming Qiu Zhang
Three-dimensional carbon-based foam (3D-CF) possesses many fascinating properties such as giant conductivity, high thermal insulation , outstanding mechanical performance, and excellent chemical and thermal stabilities. However, most 3D-CFs acquired by the previously reported fabrication methods have some limitations, such as uncontrollable morphology, plenty of inherent defects, difficult to realize self-standing after removing sacrificial template, and overlapping joint flaws among graphene layers . Although significant research efforts have been devoted to develop 3D foam, it is still a challenging task to obtain 3D-CF with both high conductivity and outstanding mechanical performance, simultaneously. To address this issue, a novel and easy fabricating approach for 3D ultrathin-graphite carbon foam (3D-UGF) was explored by a morphology-retaining pyrolysis of polyaniline foam precursors. The typical 3D-UGF graphitized at 2800 °C exhibited stronger compressive strength and electrical conductivity under the compressive strain of 90%, and remained constant even after 2000 cycles, which are comparable to the previously reported state-of-the-art 3D-CF foam with the same density. Cycling performance of the lithium-sulfur and lithium-air batteries with the 3D-UGF as binder-free cathode is as high as 1590 mAh g −1 and 920 mAh g −1 after deep discharge/charge 100 cycles, respectively.
研究领域:
材料科学
·
储能
·
纳米技术
·
电化学
✓ 已验证
DOI
高影响因子
Frontiers in Chemistry
·
2022
·
IF 5.545
Qin Xiaoyun,Fu Cuicui,Zhang Jin,Shao Wenlong,Qin Xiaomei,Gui Yanghai,Wang Lan,Guo Huishi,Chen Fenghua,Jiang Liying,Wu Gang,Bikker Floris J.,Luo Dan
The fluorescent carbon dots (CDs) have found their extensive applications in sensing, bioimaging, and photoelectronic devices. In general terms, the synthesis of CDs is straight-forward, though their subsequent purification can be laborious. Therefore, there is a need for easier ways to generate solid CDs with a high conversion yield. Herein, we used collagen waste as a carbon source in producing solid CDs through a calcination procedure without additional chemical decomposition treatment of the raw material. Considering a mass of acid has destroyed the original protein macromolecules into the assembled structure with amino acids and peptide chains in the commercial extraction procedure of collagen product. The residual tissues were assembled with weak intermolecular interactions, which would easily undergo dehydration, polymerization, and carbonization during the heat treatment to produce solid CDs directly. The calcination parameters were surveyed to give the highest conversion yield at 78%, which occurred at 300°C for 2 h. N and S atomic doping CDs (N-CDs and S-CDs) were synthesized at a similar process except for immersion of the collagen waste in sulfuric acid or nitric acid in advance. Further experiments suggested the prepared CDs can serve as an excellent sensor platform for Fe3+ in an acid medium with high anti-interference. The cytotoxicity assays confirmed the biosafety and biocompatibility of the CDs, suggesting potential applications in bioimaging. This work provides a new avenue for preparing solid CDs with high conversion yield.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2022
·
IF 16.744
Ke-Ying Tao,Kuo Yuan,Wei Yang,Di-Chang Zhong,Tong-Bu Lu
Photocatalytic CO 2 reduction reaction (CO 2 RR) is an effective mean to address the current environmental and energy issues. As a kind of typical photocatalyst, g-C 3 N 4 possesses lots of advantages (i.e . , facile synthesis, visible-light response, and high stability) in CO 2 reduction. However, the poor capacity of CO 2 capture and rapid recombination of photo-generated electron and hole, both hinder the further development of g-C 3 N 4 for CO 2 RR. Herein, we developed a template co-pyrolysis strategy to prepare C–NH x -rich ( x = 1 or 2) g-C 3 N 4 , to increase the CO 2 binding and the subsequent photocatalytic CO 2 reduction efficiency. Specifically, organic molecules with multiple imino groups were used as additives to co-pyrolyze with urea. These additives can act as templates to facilitate the formation of g-C 3 N 4 with abundant C–NH x groups, which effectively improved the capacity of CO 2 capture. Meanwhile, the capacity of light absorption and the separation of photo-generated electron and hole were also optimized. As a result, the obtained C–NH x -rich g-C 3 N 4 showed greatly enhanced photocatalytic activity for CO 2 RR, over 74-fold higher than that of g-C 3 N 4 conventionally prepared. This work provides a new avenue for optimizing the g-C 3 N 4 -based photocatalysts for CO 2 RR.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
·
2022
·
IF 6.437
Xin Jin,Lunjing Yan,Beibei Cui,Jiao Kong,Meijun Wang,Liping Chang,Frederik Ronsse,Weiren Bao
The carbon material prepared by co-pyrolysis of biochar and caking coal has been proved that it acts in catalytic conversion of volatiles and could be used in a granular bed duster as filter medium due to its high abrasive resistance in the coal pyrolysis technology. In this work, inactive carbon material loaded by nickel (Ni/ICM) was prepared by pyrolysis of the blend of biochar ion exchanged with nickel and caking coal, and then was steam activated obtaining activated carbon material loaded by nickel (Ni/ACM). The study investigated the in-situ catalytic conversion process of coal pyrolysis volatiles over Ni/ICM and Ni/ACM in a continuous pyrolysis downer-bed reactor. The physical and chemical properties of Ni/ICM and Ni/ACM, pyrolysis product distribution and the component of tar were analyzed, especially, the coke suspended in tar (Coke-S) was separated from tar and characterized in detail. Results show that the crystallite size of Ni and NiO in Ni/ICM is about 5–7 nm, and that is slightly larger in Ni/ACM. Compared to Ni/ICM, more nickel species, pores, acid sites, oxygen-containing functional groups and carbon defects are contained in Ni/ACM. The yields of tar and light tar (boiling point below 360 °C) are higher over Ni/ICM than over Ni/ACM. Ni/ICM further improves the tar quality compared to ICM, and the content of light oil in tar increases from 22.0 wt% over ICM to 30.6 wt% over Ni 3.2 /ICM. The highest light oil yield is obtained over Ni 1.9 /ICM as 3.6 wt% and the lowest pitch yield is obtained over Ni 3.2 /ICM as 3.5 wt%. The characterization of Coke-S shows that it is composed of large aromatic clusters crosslinked by oxygen and fine ash particles. The large aromatic clusters, as heavy component in tar, are found that its H/C molar ratio increases and condensation degree decreases over Ni/ICM and Ni/ACM in comparison with ICM and ACM, respectively, which also means that the quality of tar is improved. Besides, the oxygen in the tar may have been transferred to the coke.
✓ 已验证
产品关联
DOI
高影响因子
ENERGY
·
2022
·
IF 8.857
Haifeng Jiang,Haipeng Liu,Jiaxin Dong,Jiaxing Song,Sunhua Deng,Jie Chen,Yu Zhang,Wenpeng Hong
Using cellulose to produce high-quality oxygenated fuels or chemicals is becoming an important way to replace chemical synthesis technology. In this work, the Ce–Co–Na ternary composite metal catalyst is synthesized and used for catalytic cracking of cellulose to prepare the ketone-rich bio-oil production. To construct an environment-friendly process, CO 2 is used as a pyrolysis reaction atmosphere to improve the enrichment of ketones. Strong synergistic effects among metal components effectively promote the thermal-cracking of cellulose to produce primary products (anhydrosugars), and further convert to oxygenates due to the excellent oxygen transferability of the catalyst. The introduction of CO 2 enhances the selectivity of ketones in the liquid product, especially 2,3-dimethyl-2-cyclopenten-1-one. The highest content of ketones in the liquid is 22.73%, which is about four times higher than that of the blank sample. In addition, the generation of CO in the syngas is promoted. This study provides an alternative way for the pyrolysis of biomass to prepare ketone platform compounds and syngas production .
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2022
·
IF 6.371
Xiaotong Zhu,Yuanyuan Zhang,Shengxiao Zhang,Shuangshuang Yang,Qiang Xu
In this study, biomass carbon supported with iron and cobalt bimetal (FeCo/BC) was synthesized by a one-pot calcination method to activate peroxymonosulfate (PMS) and peroxydisulfate (PDS) for bisphenol A (BPA) degradation. Characterization with X-ray diffraction, X-ray photoelectron spectroscopy and high resolution transmission electron microscopy showed that Fe 0 , Fe 3 O 4 , Co 0 and CoO nanocrystals were included in FeCo/BC materials. The degradation results showed Fe 0.6 Co 0.4 /BC had excellent catalytic activation performance for PMS or PDS. The Fe 0.6 Co 0.4 /BC (0.0050 g) combined with 0.25 g·L −1 of PMS could completely degrade 20 mg·L −1 BPA within 8 min, and the same amount of BPA could be removed with 0.020 g Fe 0.6 Co 0.4 /BC in the presence of 0.25 g·L −1 PDS within 20 min. The corresponding total organic carbon removal rates reached 83.49% and 77.5% respectively after 2 h. The Fe 0.6 Co 0.4 /BC also had good adaptability to solution pH and practical water body. After five cycles, the degradation rates of BPA in the two systems were all over 90%, and excellent magnetism was beneficial to the reuse of catalysts. Electron paramagnetic resonance and free radical quenching tests indicated that SO 4 •- , •OH, and 1 O 2 were the main active species involved in the BPA degradation. This work not only provided a promising catalyst for the degradation of organic pollutants, but also elucidated the synergistic effect between Fe-Co bimetal alloys during PMS and PDS activation, which would facilitate the design, synthesis, and application of catalytic materials with high efficiency.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ENVIRONMENTAL MANAGEMENT
·
2022
·
IF 8.91
Jiaxing Song,Jun Wang,Yuhan Pan,Xudong Du,Jingyuan Sima,Chenxi Zhu,Fangfang Lou,Qunxing Huang
The increasing demand for plastics has resulted in significant plastic waste accumulation and environmental pollution . Catalytic pyrolysis is an attractive treatment method to mitigate the plastic waste management problems and recover high-value oil products. In our study, waste polyethylene (PE) was pyrolyzed to produce benzene, toluene, ethylbenzene and xylene (BTEX)-enriched oil a using dielectric barrier discharge plasma catalytic pyrolysis reactor. Ga-modified Hydro-Zeolite Socony Mobile-Five (HZSM-5) was used as a pyrolysis catalyst. The effects of the PE to Ga/HZSM-5 ratio and discharge power on BTEX enhancement and carbon deposition are discussed. The greatest BTEX selectivity (77.04%) and relatively low coke yield (1.37%) were achieved when the PE/(Ga/HZSM-5) ratio was 2:1 with a non-thermal plasma (NTP) discharge power of 20 W. The regeneration effects of conventional thermal oxidation and NTP on the zeolite catalyst were compared. NTP regeneration at a low temperature (150 °C) achieved the same coke removal rate as that of thermal regeneration at high temperatures (500 °C). Ga/HZSM-5 subjected to NTP regeneration showed higher activity for BTEX formation (BTEX selectivity was 42.10%) as compared to that shown by Ga/HZSM-5 subjected to thermal regeneration (BTEX selectivity was 40.59%). The NTP synergistic catalytic pyrolysis of plastics over Ga/HZSM-5 was found to be a promising strategy for mitigating the plastic waste management problems and upgrading the quality of oil products.
✓ 已验证
DOI
高影响因子
FUEL
·
2022
·
IF 8.035
Qi Zhao,Xianfeng Chen,Yi Li,Huaming Dai
To explore the suppression mechanisms of ammonium polyphosphate (APP) on methane/coal dust explosion flame, the experiment tests of methane/coal dust explosion flame propagation under different mass fraction of APP were conducted in a vertical pipe. Using Simultaneous Thermal Analysis and Py-GC/MS to analyze the effects of APP on the thermal decomposition process and thermal pyrolysis products of coal dust. The chemical characterization of explosion residues was carried out by confocal Raman and Fourier transform infrared spectroscopy (FTIR). Based on the apparent suppression ways of APP such as absorption of heat, reduction concentration of combustibles and adsorbent of free radicals, APP also limited the thermal decomposition process of coal dust and leaded to the reduction or even disappearance of some organic matters at coal dust pyrolysis. Noticeably, the investigation of explosion residues found that the carbonization effect of APP pyrolysis products and the activity reduction of functional groups (–CH 3 /–CH 2 and –OH) which contribute to ignition of coal dust, these coupling effects made it difficult for coal dust to ignite, and thus the methane/coal dust compound explosion were suppressed significantly.
✓ 已验证
产品关联
DOI
高影响因子
Frontiers in Energy Research
·
2022
·
IF 3.858
Wang Hongfei,Zhao Xiqiang,Yang Xinfei,Sun Shuang,Wang Wenlong,Mao Yanpeng,Song Zhanlong
In this paper, two types of adsorption materials SA-C-Fe and SA-C-Fe(C) were prepared using bagasse biochar produced by one-step microwave pyrolysis and activation for Cr(VI) removal of wastewater. The adsorption materials were characterized, and Cr(VI) adsorption performance, kinetics and thermodynamics on adsorption materials were studied. Results show that microwave pyrolysis/activation contributes to developed pore structure and abundant active functional groups, resulting in high Cr(VI) adsorption capacities. The optimal preparation conditions for biochar is: microwave power 500 W, ZnCl2/bagasse ratio 2.5:1 and pyrolysis/activation time 15 min, and the specific surface area of biochar is 1,787.64 m2/g. The Cr(VI) adsorption of the two materials is more in line with the pseudo-second-order kinetic model, and the adsorption process is dominated by chemical adsorption. The static removal experiment of Cr(VI) using SA-C-Fe and SA-C-Fe(C) has the best removal effect at pH = 2, and the whole adsorption process is more in line with the Langmuir-Freundlich isotherm model. Calculated by the pseudo-two-order kinetic model and the Langmuir-Freundlich isothermal model, the maximum adsorption rate for Cr(VI) of SA-C-Fe and SA-C-Fe(C) are 211.87 mg/g and 388.92 mg/g, respectively. The removal process is mainly dominated by three mechanisms: electrostatic adsorption, ion exchange and redox reactions. The improvement of Cr(VI) adsorption capacity is attributed to more developed pore structure. The results offer beneficial reference for the application of low-cost carbon-based adsorption materials for pollutants separation, and effectively realize the utilization of bagasse pyrolysis by-products.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2021
·
IF 5.316
Cheng Cheng,Jian Wang,Zhihao Zhao,Changchun Chen,Sheng Cui,Yifeng Wang,Lin Pan,Yaru Ni,Chunhua Lu
Semiconductor catalyst with high photocatalytic activity can be exploited via heterojunction. In this study, a new S-scheme SrTiO 3 /porous ZnO composite was rationally devised, successfully prepared by utilizing a two-step pyrolysis of SrTiO 3 /ZIF-8, and analyzed by various characterization technologies including XRD, SEM, TEM, BET, XPS, PL, UV–vis DRS, and photoelectrochemical and DFT theoretical calculations. A porous structure, tight contact, and a heterojunction formed between SrTiO 3 and porous ZnO (ZnOT) can be observed by SEM and TEM images. BET testing indicates that the SrTiO 3 /porous ZnO composite (S3ZT) shows the highest specific surface area (30.37 m 2 /g). The band gap values (E g ) of SrTiO 3 and ZnOT are around 3.17 and 2.95 eV, which agree with those obtained from DFT calculations. Compared to other samples, the SrTiO 3 /porous ZnO composite (S3ZT) shows higher light absorption and lower transfer resistance as demonstrated by UV–vis DRS and EIS results. S3ZT presents a superior photocatalytic efficiency of 48.8% in degrading 5 mg/L methyl orange (MO) irradiated by 1 h UV–vis light, which are 7- and 1.5-fold higher than pristine SrTiO 3 and ZnOT, respectively. Moreover, based on Mott-Schottky theory, active species trapping experiments, XPS determination, and DFT calculations (energy band gap and work function), it was shown to be reasonable to utilize the S-scheme charge migration process for an explanation regarding the better photocatalytic activity of SrTiO 3 /porous ZnO composite. Overall, this work will provide an effective protocol for devising and preparing semiconductor photocatalysts with S-scheme heterojunction by utilizing the superior characteristics of MOFs.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2021
·
IF 10.588
Leilei Cheng,Yuyuan Zhang,Yazhuo Wang,Jing Gu,Haoran Yuan,Yong Chen
Converting plastic wastes into value-added products through energy-efficient pyrolysis is essential, and it requires lower pyrolysis temperatures and shorter processing times than that of other processes. An exothermic phenomenon was observed during the process high-pressure polyethylene pyrolysis. It was proven for the first time that the exotherm is caused by a pressure-induced phase transition, in which colossal heat release can be driven by relatively small pressures. A large temperature change (> 100 °C) leads to the deep cracking of polyethylene, although the set temperature is far lower than the required temperature for thermal cracking. Importantly, the heat input stops immediately when the set temperature is reached; thus, the external heating time is short. Polyethylene can be completely converted into liquid products in ~90 wt% yield and with a small number of gases. The self-exothermic phase transition only occurs within a certain range of material thickness, which is related to the corresponding phase behavior. In the self-exothermic pyrolysis process, with an increase in the thickness of polyethylene, the proportion of low-value olefins in oil products decreases gradually, while alkanes, isoalkanes and aromatics show an increasing trend, making the product composition closer to the fuel standard. This work provides a viable approach for plastic recycling at low pyrolysis temperatures and short external heating times with the help of a self-exothermic phase transition in the absence of a catalyst.
✓ 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）