CHEMOSPHERE
·
2021
·
IF 7.086
Wei Zhou,Xiaoxiao Meng,Jihui Gao,Fei Sun,Guangbo Zhao
s Hydrogen peroxide (H 2 O 2 ) electrosynthesis from 2-electron O 2 reduction reaction (2eORR) is widely regarded as a promising alternative to the current industry-dominant anthraquinone process. Design and fabrication of effective, low-cost carbon-based electrodes is one of the priorities. Many previous work well confirmed that hydrophilic carbon-based electrodes are preferable for 2eORR. Here, we proposed a strategy of hydrophilicity-hydrophobicity regulation. By using commercially available graphite felt (GF) as electrodes, we showed that both hydrophilic GF, hydrophobic GF, and Janus GF yielded significantly higher H 2 O 2 production, which is 7.3 times, 7.6 times, and 7.7 times higher than the original GF, respectively. Results showed that currents and stirring rates affect the H 2 O 2 yields. The enhancement of hydrophilic GF is due to the incorporation of oxygen-containing functional groups, while the hydrophobic and Janus GF comes from the locally confined O 2 bubbles, which built a gas-liquid-solid interface inside GF and thus enhance the H 2 O 2 formation kinetics. Finally, the effectiveness of the hydrophilicity-hydrophobicity regulation concept was tested in Electro-Fenton process by removing typical dyes and antibiotics. This work supply an effective but facile strategy to enhance the performance of carbon-based electrodes towards 2eORR by regulating the micro-environment of electrodes.
研究领域:
环境科学
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电化学工程
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材料科学
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产品关联
DOI
PubMed
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2020
·
IF 16.683
Yanbin Wang,Di Meng,Xu Zhao
Visible-light-driven H 2 O 2 production from O 2 reduction is an eco-friendly strategy and attracts increasing attentions. In this study, KOH modified graphitic carbon nitrides (CNKx) were constructed through the thermolysis of melamine-cyanuric acid supramolecular-complex in the presence of KOH. The BET specific surface area of CNK 0.2 with porous structure was 92 m 2 g −1 . The photocatalyst was characterized by XPS, ESR and element analysis and the analysis suggested that nitrogen vacancy was created in the framework of g-C 3 N 4 . Photoluminescence (PL) spectra indicated that the recombination of photogenerated electrons and holes was efficiently suppressed. ζ-potential revealed that more negative charge on the surface of CNK 0.2 , which promoted the adsorption of O 2 and accelerated the photocatalytic H 2 O 2 production. ESR experimental and radical quenching results illustrated that superoxide radical (O 2 - ) was the primary intermediate during the O 2 reduction process, suggesting the O 2 reduction pathway by CNK 0.2 was the sequential two-step single-electron reduction.
研究领域:
材料科学
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环境科学
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光催化
✓ 已验证
产品关联
DOI
高影响因子
ACS Catalysis
·
2020
·
IF 12.35
Mo Zhang,Zheng Li,Xing Xin,Junhao Zhang,Yeqin Feng,Hongjin Lv
Selective production of value-added platform chemicals from renewable biomass feedstocks and their derivatives has attracted tremendous attention with high potential in addressing global problems of energy and sustainability. In this work, a lead-halide perovskite (MAPbBr3, MA = methylammonium) is utilized as a photocatalyst for selective oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-diformylfuran (DFF) using atmospheric O2 upon visible-light irradiation. Under minimally optimized conditions, the photocatalytic conversion of HMF in acetonitrile solvent reaches 100% with a DFF selectivity of over 90%, achieving an overall furanic carbon yield of over 96%. A detailed catalytic mechanism was proposed based on various spectroscopic and experimental results, revealing that the atmospheric O2, photogenerated electrons (e–), holes (h+), •O2–, and 1O2 species together play crucial roles in the effective and selective photo-oxidation of HMF to DFF. In addition, our present photocatalytic system is also applicable for photo-oxidation of benzyl alcohol with approximately 100% conversion and benzaldehyde selectivity, providing insights for future exploration of the present catalytic system.
研究领域:
化学工程
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可再生能源
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry A
·
2019
·Vol. 8
·期 1
·259-267
·
IF 10.733
Congcong Dang,Yu Wang,Biao He,Weibin Zhang,Feng Dang,Hongchao Wang,Yong Du
Searching for highly efficient and low cost electrocatalysts is an urgent challenge to provide high capacity and long cycle life Li–O2 batteries (LOBs). In this work, the highly efficient electrocatalytic properties of MoSi2 were first demonstrated using particles prepared by a solid–state reaction method. The surface was activated, playing a dominant role in the electrocatalytic performance. After acid etching to remove SiO2 impurities arising from the surface oxidation, MoSi2 exhibited excellent bifunctional electrocatalytic properties for LOBs. Mo6+ on the surface contributed to the initial low overpotentials of 0.45 V (3.2 V for the OER and 2.75 V for the ORR) and transformed into Mo4+ for a long cycle life. As a consequence, outstanding rate capabilities of 12 708 mA h g−1 at 100 mA g−1 and 10 794 mA h g−1 at 800 mA g−1, and excellent cycle durability of 215 and 90 cycles at a limited capacity of 1000 mA h g−1 at 200 and 500 mA g−1, respectively, were obtained for the MoSi2 cathode.
研究领域:
材料科学
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电化学
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能源存储
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2019
·Vol. 9
·期 29
·16288-16295
·
IF 3.049
Shu-ying Zhen,Hai-tao Wu,Yan Wang,Na Li,Hao-sen Chen,Wei-li Song,Zhen-hua Wang,Wang Sun,Ke-ning Sun
Herein, hollow porous CuO–CuCo2O4 dodecahedrons are synthesized by using a simple self-sacrificial metal–organic framework (MOF) template, which resulted in dodecahedron morphology with hierarchically porous architecture. When evaluated as a cathodic electrocatalyst in lithium–oxygen batteries, the CuO–CuCo2O4 composite exhibits a significantly enhanced electrochemical performance, delivering an initial capacity of 6844 mA h g−1 with a remarkably decreased discharge/charge overpotential to 1.15 V (vs. Li/Li+) at a current density of 100 mA g−1 and showing excellent cyclic stability up to 111 charge/discharge cycles under a cut-off capacity of 1000 mA h g−1 at 400 mA g−1. The outstanding electrochemical performance of CuO–CuCo2O4 composite can be owing to the intrinsic catalytic activity, unique porous structure and the presence of substantial electrocatalytic sites. The ex situ XRD and SEM are also carried out to reveal the charge/discharge behavior and demonstrate the excellent reversibility of the CuO–CuCo2O4 based electrode.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
FUEL
·
2023
·
IF 7.4
Qi Rong,Wenkai Huang,Fuhua Xu,Yanlan Wang,Changlong Wang,Xiang Liu
In spite of significant developments are accomplished in the exploration of H 2 and O 2 evolution upon water electrolysis/photolysis, this remains a challenge to design and develop ideal catalytic systems for this reaction and to isolate H 2 from H 2 -O 2 mixture with membranes. Herein, a series of ZIF-67-supported transition metal nanoparticles (TMNPs/ZIF-67), including Pt, Ir, Pd, Rh, Au and Ag, via immobilization of ultrafine TMNPs at the surface of ZIF-67, have been designed and developed for the selective H 2 generation from NH 3 BH 3 hydrolysis and O 2 evolution upon H 2 O 2 decomposition. In particular, the optimized nanocatalyst Pt/ZIF-67 presents the super-high catalytic property in the both H 2 evolution upon NH 3 BH 3 hydrolysis (689 mol(H 2 )·mol Pt -1 ·min −1 ) and O 2 evolution upon H 2 O 2 decomposition (979 mol(O 2 )·mol Pt -1 ·min −1) at 30 °C. Importantly, the selective “on–off” control for demand-based H 2 generation from NH 3 BH 3 hydrolysis was successfully realized by Zn 2+ /EDTA-2Na system. This highly efficient Pt/ZIF-67 proposed a new method for the promising potential application of ammonia borane and hydrogen peroxide as an economic and safe H 2 resp. O 2 carrier for fuel cell.
研究领域:
化学催化
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燃料电池材料
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纳米材料
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2017
·
IF 6.216
Ruxin Peng,Jihai Shao,Yuanlin Xie,Anwei Chen,Liang Peng,Qingru Zeng,Si Luo
Being that the influence of organic ligands on contaminant removal by nanoscale zero valent iron (nZVI) has been explored in quite a few studies, there is little information on reaction mechanisms of the ZVI-ligand system under different aeration conditions. The degradation of nitrobenzene (NB) by nZVI-oxalic acids (OA) was investigated under N 2 , O 2 and without aeration conditions. From the findings, it was evident that OA dramatically improved NB degradation by nZVI with all of the aeration conditions. Approximately 100% of NB was degraded by nZVI-OA+N 2 system after 60 min of reaction, followed in effectiveness by nZVI-OA+ without aeration (95%) as well as nZVI-OA+O 2 (85%). Operation parameters including OA concentration and pH had significant effect on the removal of NB in the nZVI-OA system. 3 mM OA concentration and pH 3.0 were found to be favourable. The Fe 2+ , total dissolved iron concentrations, pH and ORP values in the nZVI-OA systems had also been monitored. Intermediates and trapping experiments showed that reduction played a fundamental role in the NB degradation by nZVI-OA under N 2 or without aeration conditions. The formation of Fe(OA) 0 and Fe(OA) 2 2− complexes had lower standard ORP, which could improve the strength of reductant in the systems, and thus resulting in an increased degradation efficiency of NB by nZVI-OA+N 2 . Under O 2 aeration condition, the NB degradation process could be regarded as an oxidation . In the meantime, OA promoted the production of reactive oxidants species by speeding up the oxidation rates of Fe 2+ by O 2 and H 2 O 2 . Summarily, the improved reactivity of nZVI was largely as a result of the strong complexation ability of OA.
研究领域:
环境科学
·
化学
✓ 已验证
DOI
高影响因子
FUEL PROCESSING TECHNOLOGY
·
2018
·
IF 3.956
Ting Lu,Yucui Hou,Weize Wu,Muge Niu,Wei Li,Shuhang Ren
Carboxylic acids are considered as an important group of chemicals. Direct conversion of cellulose to formic acid (FA) by vanadium(V(V))-contained catalyst is of significant conceptual and practical interest. A second metal (from Mg(II), Ca(II), Al(III), Cr(III), Mo(VI), Mn(II), Cu(II), or Fe(III)) incorporated into V(V)-contained catalyst system was screened to further improve the oxidation of cellulose by O 2 to yield FA. Fe(III) exhibited the best performance and effects of reaction parameters on the conversion of cellulose in NaVO 3 -FeCl 3 -H 2 SO 4 aqueous solution were investigated. Cellulose could be rapidly converted, and the yield of FA (66.8%) was higher than that obtained by the single use of FeCl 3 (48.4%) or NaVO 3 (57.6%). The conversion of cellulose in another V(V)-contained catalyst system (H 5 PV 2 Mo 10 O 40 ) was explored to verify the universal enhancement of FeCl 3 . Influences of the second metal Fe(III) on the V(V)-contained catalyst system and mechanism of cellulose oxidation in the V(V)-Fe(III)-H 2 SO 4 system were studied. Compared with single use of V(V), the employment of Fe(III) alone is not active enough in the oxidative C C bond cleavage . V(V) other than Fe(III) is the main active species for selective oxidation of substrates. The incorporation of Fe(III) and V(V) shows both synergistic and competitive relationships. Both the synergistic and competitive effects are beneficial to increase FA yield, as they promote the oxidation of V(IV) to V(V), increase oxidative ability, and inhibit the overoxidation to by-product CO 2 . The catalyst system was reused four times without decline in activity.
研究领域:
化学工程
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry A
·
2018
·Vol. 6
·期 10
·4485-4493
·
IF 9.931
Lingyou Zeng,Kaian Sun,Zhichao Yang,Shengli Xie,Yanju Chen,Zhi Liu,Yaqing Liu,Jinchong Zhao,Yunqi Liu,Chenguang Liu
Three-dimensional (3D) nanomaterials have received significant attention for large-scale functional applications due to their large specific surface areas as well as desired electrical, physicochemical, and catalytic properties. Herein, we present a facile and effective synthetic route for in situ grown 3D hierarchical Ni3S2 superstructures (rod-like arrays and nanoforest patterns) on nickel foam. This handy strategy endows the Ni3S2 superstructures with large surface active areas, porosity, and macro-/mesoporous structures. We have shown that these materials can serve as highly active, binder-free, bifunctional electrocatalysts for both the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Moreover, these materials were found to provide a ∼100% faradaic yield towards both HER and OER and exhibit remarkable catalytic stability (for >50 h).
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
Polymer Chemistry
·
2018
·Vol. 9
·期 9
·1095-1108
·
IF 4.927
Xiaoqi Zhao,Wentao Wu,Jian Zhang,Wenxue Dai,Youliang Zhao
Multicomponent miktoarm stars with multifunctional Y junctions may provide us with new insights into their physicochemical properties and prospective applications. Considering the unique role of a gas stimulus in smart materials and the promising gradient-type properties induced by combined stimuli, this study aims at the synthesis, thermoresponsive and self-assembly behaviors of an O2-, redox-, thermo-, and pH-responsive 3-miktoarm star quarterpolymer. A robust method involving controlled polymerization, amine–thiol–ene conjugation and hydrolysis was developed to achieve a poly(N-isopropylacrylamide-co-4-(2-(2,2,2-trifluoroethylcarbamoyl)ethylthio)-2-(acrylamido)-N-(2-hydroxyethyl)butanamide)-arm-poly(ε-caprolactone)-arm-poly(acrylic acid) star. Owing to the changes in amphiphilicity, chemical composition and mutual interactions, a single stimulus or various stimuli combinations could lead to switchable LCSTs and morphological transformations. Upon increasing pH, O2 treatment and oxidation, the copolymer solution was liable to exhibit enhanced LCST due to the improved hydrophilicity. The star quarterpolymer could self-assemble into multicompartment vesicles (pH 3.0), vesicles (pH 5.9) and small micelle/vesicle mixtures (pH 10) at ambient temperature. Upon thermo, redox and O2 stimuli, the assemblies formed at different pHs could be further converted into some other morphologies such as compound micelles and nanocapsules with hollow caves. Our research affords a general route to synthesize MMSs with tailored Y junctions, and the combination of the O2 stimulus with other stimuli may potentially expand the scope of multi-triggered properties and applications of star copolymers.
研究领域:
高分子化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2018
·
IF 5.116
Zhengyi Qian,Baoyu Sun,Lei Du,Shuaifeng Lou,Chunyu Du,Pengjian Zuo,Yulin Ma,Xinqun Cheng,YunZhi Gao,Geping Yin
Since electrode surfaces primarily house the sites of oxygen reduction/evolution reactions, surface chemistry is pivotal for both charge and discharge processes of Li–O 2 batteries . Herein, we introduce oxygen-containing functional groups associated with defects on the carbon fiber papers (functionalization) via acid treatment and investigate their effects on the rechargeable nonaqueous Li–O 2 batteries. The discharge platform increases from 2.68 V to 2.79 V, meanwhile the decreased charge overpotential (a drop of 0.84 V) is also observed after functionalization. It is found that the discharge products formed on pristine carbon fiber exhibit a huge toroidal-like structure, in contrast to the porous flake clusters with much smaller size on the functionalized carbon fiber. On the other hand, the smaller product clusters are found to be much easier to be oxidized, leading to remarkably reduced charge overpotential. In this regard, the decomposition of electrolyte and corrosion of carbon cathode are dramatically alleviated, thus leading to greatly promoted cycling performance. All the experimental facts suggest that the oxygen functional groups associated with defects could provide tremendous active sites for the nucleation of discharge products and result in remarkably decreased overpotential for both the oxygen reduction and the oxygen evolution reaction in our cases.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
·
2017
·Vol. 164
·期 13
·G112
·
IF 3.259
Yuchen Hui,Xiaoyan Ma,Fengjin Qu,Fang Chen,Ying Chen
A practical strategy is developed to fabricate stable glucose/O2 biofuel cells with high power density assembled by enzymatic bio-electrodes based on three-dimensional nickel foam. The porous three-dimensional nickel foam is used as a substrate to enhance the enzyme loading, while the reduced graphene oxide and gold nanoparticles decorating on the nickel foam are employed as the direct electron transfer system for bio-anodes and bio-cathodes. The ferrocenecarboxylic acid serves for the mediated electron transfer to further increase electron transfer rate for glucose oxidase electrodes. Covalent bond is employed to immobilize the mediator and enzymes for improving the stability of bio-electrodes and biofuel cells. As the results, the surface glucose oxidase loading reaches to 4.03 × 10−7 mol cm−2 with good enzymatic activity. Additionally, the obtained glucose/O2 biofuel cells exhibit an outstanding maximum power density of 2.84 ± 0.09 mW cm−2, with a remarkable long-term operational stability for retaining 85.5% of its performance after 70 days. In human blood, the biofuel cell shows a favorable output performance of 0.39 ± 0.04 mW cm−2, implying the appropriateness for practical applications.
研究领域:
生物化学
·
材料科学
·
能源技术
✓ 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）