OPTICAL MATERIALS
·
2024
·
IF 3.8
Worku Lakew Kebede,Kuo Dong-Hau,Chen Xiaoyun
Metal oxide semiconductor photocatalysts have received remarkable consideration as a promising technology for environmental remediation and energy conversion. Oxysulfide semiconductors have narrow band gaps which are appropriate for photocatalytic removal of toxic organic pollutants under visible light illumination. For the elimination purpose of these pollutants, Mo(O,S) 2 , Mn(O,S) 2 , and Mn–Mo(O,S) 2 oxysulfide catalysts containing various Mn contents were synthesized at low temperatures via a simple method. The structural, morphological, electrochemical, compositional, and optical properties of the as-synthesized catalysts were exhaustively characterized. The photocatalytic degradation activity of the bares Mo(O,S) 2 , Mn(O,S) 2 , and other Mn–Mo(O,S) 2 compositions were evaluated over different types of organic pollutants under visible light illumination. The addition of Mn in Mo(O,S) 2 structure improved the photodegradation activity, and Mn–Mo(O,S) 2 -30 was found to be the best composition with superior photodegradation performance towards the four cationic, anionic, and neutral dyes. The degradation efficiency of 10 ppm of MB, and MO dyes reach 99.7 % and 98.6 %, within 30 and 120 min, respectively. Mn–Mo(O,S) 2 -30 catalyst also shows a good photodegradation performance on Rh B and NR organic pollutants. According to the recycling test, the catalyst exhibited excellent performance. The photodegradation follows pseudo-first order kinetics with a rate constant of 0.097 and 0.036 min −1 for MB and MO dyes, respectively. The trapping experiment showed that superoxide anion radicals (O 2 •- ) and holes (h + ) are the responsible active species for the degradation on MO and MB, respectively. The novelty of using Mn–Mo(O,S) 2 -30 for various dyes degradation lies in its remarkable catalytic properties.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
ACS Applied Energy Materials
·
2020
·
IF 4.473
Yin’an Zhu,Ye Pan,Weiji Dai,Tao Lu
Electrochemical splitting of water to hydrogen is widely considered as an efficient and sustainable solution to relieve the energy crisis. In this work, we report a facile dealloying method based on metallic glass (Ni61Zr36Mo3) to introduce abundant oxygen vacancies (Ov) for the electrocatalytic hydrogen evolution reaction (HER). The corroded ribbons are composed of a sandwich-like structure with Ni–Mo–O nanoporous layer outside and raw metallic glass inside. This complex structure delivers a low overpotential of 71 ± 2.6 mV at −20 mA cm–2geo in 1.0 M KOH solution, a Tafel slope of 57 ± 3 mV dec–1, and 100 h long-term stability for HER, which is much better than those of the crystallized counterpart, nanoporous Ni, and the commercial benchmark 20% Pt/C electrocatalyst. The high concentration of oxygen vacancies (71.5%), the alloying effect of Mo, and amorphous composition synergistically contribute to the superior electrocatalytic ability and enhanced reaction kinetic of nanoporous Ni–Mo–O, indicating it an excellent low-cost alternative for platinum in hydrogen production.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2020
·Vol. 44
·期 45
·19868-19879
·
IF 3.288
Sleshi Fentie Tadesse,Dong-Hau Kuo,Worku Lakew Kebede,Lalisa Wakjira Duresa
Discharging of organic pollutants from industrial activities into the water bodies is a common worldwide problem, which can adversely affect human life and the environment. Recently, many efficient, eco-friendly, and cost-effective photocatalytic methods have been investigated for environmental remediation. In this study, a simple and facile precipitation method at low temperature was proposed for the synthesis of V-doped Mo(O,S)2 oxysulfide. The crystallinity, morphology, elemental composition, and optical and electrical properties of the as-synthesized materials were characterized by XRD, Raman spectroscopy, FT-IR spectroscopy, FE-SEM, TEM, XPS, PL, and EIS. The photocatalytic performance of both bare and V-doped Mo(O,S)2 was evaluated in the degradation of methylene blue (MB) dye. The holes (h+) and hydroxyl radicals (OH˙) were identified as the main oxidative species for MB degradation. V-Mo(O,S)2-10 synthesized with 10% vanadium precursor showed the highest photocatalytic efficiency for MB degradation under visible light irradiation with an apparent rate constant of 0.028 min−1, which was much greater than that of bare Mo(O,S)2 at 0.0098 min−1. Besides, V-Mo(O,S)2-10 had the lowest recombination rate of electron–hole pairs and charge transfer resistance to enhance the photocatalytic activity, as evidenced by PL and EIS analyses. Therefore, V-doped Mo(O,S)2 can be a potential candidate for photocatalytic degradation of organic dyes for environmental remediation.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2017
·
IF 3.133
Shu Huang,Min Zhou,Kangli Wang,Shijie Cheng,Guoping Yan,Kai Jiang
Electrochemical synthesis method is an effective, controllable and cost-effective synthesis route for fabricating various kinds of metal compounds. Here, for the first time, we synthesis the Li-Mo-O compounds by electrolysing MoO 3 in molten LiCl-LiBr salt at 600 °C. The as-prepared LiMoO 2 and Li 2 MoO 4 were evaluated as novel anode materials for lithium ion batteries (LIBs), delivering high reversible capacities of 565 and 473 mAh g −1 , respectively. More significantly, the LiMoO 2 @C show extra high initial columbic efficiency of 80% with superior rate capability and long cycling stability over 200 cycles. This facile and green electrochemical synthesis route described in this work can provide new insights for the development of promising host materials for practical LIBs in large-scale energy storage applications.
研究领域:
材料科学
·
电化学
·
能源存储
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2021
·
IF 8.128
Zhiliang Jin,Teng Li,Kai Wang,Xin Guo
Simple high-temperature calcination and hydrothermal methods were followed to synthesize CeO 2 and Mo-S, respectively. The efficient photocatalytic hydrogen evolution activity exhibited by the composite catalysts can be attributed to the edge active sites in Mo-S. The Mo-O bonds formed between CeO 2 and Mo-S could further accelerate the processes of separation and migration of electrons between the catalyst interfaces. The hybrid catalyst 10%-CeO 2 /Mo-S exhibiting the best hydrogen generation ability (4.3 mmol h −1 g −1 ) was obtained by optimizing the content of CeO 2 in CeO 2 /Mo-S. Analysis of the PL spectral profile and photocurrent response recorded for the system revealed that 10%-COMS exhibited excellent photogenerated carrier separation ability. Analysis of the LSV and EIS curves revealed that 10%-COMS exhibited the optimal hydrogen production potential. The charge migration resistance provided by the systems was lower than the charge migration resistance provided by CeO 2 and Mo-S. The synergism between the S-scheme heterojunctions and the Mo-O bonds helped accelerate the separation and migration of photo-induced carriers at the catalyst interfaces. The introduction of covalent bonds in the S-scheme heterojunctions and the results presented herein can potentially help develop a new method to realize photocatalytic hydrogen evolution.
研究领域:
材料科学
·
能源科学
·
催化化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2024
·
IF 4.9
Worku Lakew Kebede,Dong-Hau Kuo,Xiaoyun Chen
Environment and energy are presently some of the highest priority topics for mankind that need to be addressed. Organic pollutants are toxic and carcinogenic for human and aquatic life hence their presence in water even in low concentrations can cause serious health problems. Photodegradation of organic pollutants by utilizing oxide-based heterostructure photocatalysts is the promising approach to carry out remediation efficiently ascribed to the advanced optoelectronic and structural superiority of oxide photocatalysts. The Zn(O,S)/Mo(O,S) 2 composites were synthesized via a facile solvothermal method at low temperatures. Several methods were used to characterize the composite morphology, structure, electrical conductivity, chemical composition, and optical characteristics. The heterostructured Zn(O,S)/Mo(O,S) 2 oxysulfide was employed successfully in the photocatalytic degradation of organic pollutants. Among the as-prepared samples, the 30-ZnMoOS composite catalyst was found to have the highest photodegradation performance on various organic dye pollutants. The photocatalytic activity of the as-synthesized Zn(O,S)/Mo(O,S) 2 samples was assessed on the photodegradation of different kinds of organic dyes under visible light irradiation. The photocatalytic degradation efficiency of 30-ZnMoOS composite over 10 ppm neutral red (NR), methylene blue (MB), rhodamine B (Rh B), and methyl orange (MO) was found to be 99.6 %, 99.9 %, 99.5 %, and 98.8 % within 40, 45, 180, and 180 min, respectively, under visible light illumination. In the present photocatalytic system, the superoxide ( . O 2 - ) anions, hydroxyl ( . OH) radicals, and holes (h + ) are proposed to be the direct reactive species causing the photodegradation of organic dyes.
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
SEPARATION AND PURIFICATION TECHNOLOGY
·
2023
·
IF 8.6
Meifei Chen,Xiunan Cai,Qing Yang,Wenqin Lu,Zuqiang Huang,Tao Gan,Huayu Hu,Yanjuan Zhang
To improve the photocatalytic performance of g-C 3 N 4 (CN), mechanical activation (MA) treatment of precursor followed by calcination was developed to construct a N−Mo−O bond bridged MoO 2 /Mo-doped CN (MA-MoO 2 /Mo-CN) Schottky heterojunction composite, which was used as a visible light-driven photocatalyst for degrading tetracycline (TC). The as-prepared MA-MoO 2 /Mo-CN with strong interfacial interaction showed excellent photocatalytic performance and structural stability, with 92.3% of TC degradation efficiency within 90 min and maintaining over 90% of degradation efficiency after five consecutive cycles. The enhanced photocatalytic performance can be ascribed to that MA treatment induced the improvement of surface area and the formation of N vacancies and N−Mo−O bonds, which served as a bridge to connect Mo-CN and MoO 2 for constructing a Schottky barrier. These provided more reactive sites and effectively enhanced migration efficiency of interface electrons, separation efficiency of photogenerated carriers, and light absorption capacity. In addition, the mechanism of photocatalytic degradation of TC and its possible degradation pathway were investigated. This research provides an environmentally friendly and feasible method for producing highly active precious metal-free photocatalysts with excellent migration and separation efficiency of photoexcited charge carriers.
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
CHEMOSPHERE
·
2020
·
IF 5.778
Worku Lakew Kebede,Dong-Hau Kuo,Fekadu Tadesse Bekena,Lalisa Wakjira Duresa
Environmentally toxic organic pollutants, namely methylene blue (MB), neutral red (NR), Rhodamine B (RhB), and methyl orange (MO) dyes contain highly toxic, carcinogenic, non-biodegradable, and colored pigments which cause harm for humans and aquatic organisms even at low concentrations. To detoxify these toxic organic pollutants from the wastewater, the bimetallic solid solution-typed In–Mo(O,S) 2 catalyst with various indium (In) contents were synthesized at low temperature through a simple precipitation method. The morphological, structural, chemical compositions, electrochemical and optical properties of the catalysts were thoroughly characterized. The photodegradation performance of the In–Mo(O,S) 2 catalysts over the cationic, anionic and neutral dyes were studied under visible light irradiation. It has been observed that the photocatalytic activity was enhanced as In was added to the Mo(O,S) 2 catalyst, and In–Mo(O,S) 2 -20 was found to be the best composition to completely degrade four organic dyes. The dye degradation had rate constant values of 9.5 × 10 −2 min −1 , 6.3 × 10 −2 min −1 , 4.4 × 10 −2 min −1 , and 15.7 × 10 −1 min −1 for MB (20 ppm), NR (20 ppm), RhB (10 ppm), and MO (10 ppm) dyes, respectively. The active species for degradation of MB is different from those for RhB and MO. Single phase In–Mo(O,S) 2 -20 capable to degrade four kinds of dyes at a fast rate is a good photocatalyst.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2020
·
IF 5.774
Fekadu Tadesse Bekena,Dong-Hau Kuo,Worku Lakew Kebede
Wastewater treatment becomes an important part to improve environmental quality and protect water resources. Thus, developing a new photocatalyst is a key solution for environmental issues. Herein, universal, highly efficient, and novel Bi 2 (O,S) 3 /Mo(O,S) 2 nanocomposite photocatalyst was fabricated by a facile method and the crystal structure, morphology, composition, and optical properties of the as-prepared catalysts were characterized in details. The photocatalytic performance of the catalysts was evaluated by the photodegradation of methyl orange (MO), rhodamine B (RhB), methylene blue (MB), and neutral red (NR), the results showed that 20% Bi-MoOS nanocomposite had excellent photodegradation activity towards all dyes. 96.0% of MO, 96.6% of RhB, 98.8% of MB and 91.3% of NR dyes were removed after 180 min, 40 min, 20 min, and 25 min visible light irradiation, respectively. The photodegradation of these dyes was further confirmed with HPLC. The excellent photocatalytic activity of the nanocomposites was due to the efficient separation and transport of photogenerated charge carriers induced by the fabricated binary heterostructures. The photodegradation fitted well the pseudo-first-order kinetics. The active species capture experiment study showed that, OH, O 2 − and h + all took parts in the degradation of dyes. The stability of the catalyst and reaction mechanism also explained in this work.
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
MATERIALS RESEARCH BULLETIN
·
2023
·
IF 5.4
Zhenjun Qing,Huapeng Zou,Xin Zhou,Haiyan Li,Yingxiang Li
This study presents the synthesis of LiYMo 2 O 8 ceramic through a solid-state reaction. XRD analysis reveals a tetragonal structure (I41/a space group) for the LiYMo 2 O 8 phase. The sample sintered at 800 °C achieved a maximum relative density of 95.8 % and exhibited excellent microwave properties: ε r = 15.7, Q × f = 24380 GHz, and τ f = 147.6 ppm/ °C. The results demonstrate a positive correlation between the relative density and both ε r and Q × f , while Q × f and τ f are found to be associated with packing fraction and Mo-O bond valence, respectively. The microwave dielectric properties are predominantly influenced by the Mo-O bond, as supported by the P-V-L theory and Raman spectroscopy analysis. Furthermore, the study reveals a correlation between ε r and the ionicity of chemical bonds, a significant impact of lattice energy on Q × f , and a relationship between τ f and bond energy and thermal expansion coefficient.
研究领域:
材料科学
·
固态化学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Chengzhi Xu,Hongyu Yang,Linzhuang Xing,Yuan Wang,Guorui Zhao,Li Chen,Zhimin Li
The Al 2 Mo 3 O 12 ceramic with monoclinic type is prepared at the sintering temperature as low as 750 °C, which exhibits excellent microwave dielectric properties of ε r = 4.99, Q × f = 49,579 GHz ( f = 14.8 GHz), and τ f = −26 ppm/°C. The relationship between structure and characteristics is analyzed through the P–V–L chemical bond theory in depth, and the dielectric properties are investigated in combination with far-infrared spectroscopy. Results show that it is Mo–O bond that is responsible mainly for bond ionicity and dielectric polarizability, and structural stability as well. Based on the far-infrared reflectivity spectra and complicated dielectric function analysis, the calculated and measured results are in relative agreement using the classical damped oscillation mode, indicating that the mode at 80.23 cm −1 is dominant for the contribution to dielectric properties. This study gives an insight into the structural characteristic and provides a guide to further improve the microwave dielectric performance of Al 2 Mo 3 O 12 ceramic.
研究领域:
材料科学
·
电子工程
✓ 已验证
产品关联
DOI
高影响因子
Catalysis Science & Technology
·
2019
·Vol. 9
·期 11
·2915-2922
·
IF 5.726
Qing Zhang,Jinhao Zhang,Huawei Yang,Yilin Dong,Yu Liu,Lixia Yang,Donglei Wei,Wenxiang Wang,Liangjiu Bai,Hou Chen
In this work, CoMo bimetallic oxides were prepared and proposed as catalysts for aerobic oxidative desulfurization (AODS) of fuels with oxygen in air as the oxidant. The bimetallic oxides could efficiently catalyze the oxidation of a series of thiophenic compounds at 80–120 °C and atmospheric pressure, while the neat Co or Mo oxide didn't show any catalytic ability, which directly proved the synergistic effect of Co and Mo. In the bimetallic system, the Co(II) sites could exhibit the capability to activate oxygen, while the Mo(IV) sites were suspected to directly participate in the oxidation of sulfides by forming reactive species. As is clearly evidenced by the characterization and experimental results, with the variation of Co/Mo proportion (2 : 1, 1 : 1 and 1 : 2), the bimetallic oxides possessed different electronic structures and surface compositions, which further led to their distinct catalytic performances. When the Co/Mo ratio was 2 : 1, the best performance was obtained, and some important reaction parameters were investigated. Furthermore, the catalyst could be reused for at least five cycles without changes in catalytic performance and chemical structure. Based on these results, it is expected that the CoMo bimetallic oxides may serve as an efficient, separable and recyclable catalyst for AODS of fuels.
研究领域:
化学工程
·
催化科学
✓ 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）