APPLIED SURFACE SCIENCE
·
2023
·
IF 6.7
Lijun Liu,Luyang Zuo,Rui Li,Tianlong Xi,Huitao Fan,Bo Li,Liya Wang
Semiconductor photocatalytic hydrogen evolution (PHE) is used to convert solar energy to hydrogen energy. Therefore, a low-cost, effective, and dependable photocatalyst could be a viable solution to environmental and energy crises. However, performing energy-conversion reactions by preparing photocatalysts with suitable photoabsorption and effective charge separation is challenging. Herein, a novel CoMn 2 O 4 -ZnIn 2 S 4 (CMO-ZIS) hollow microcube composite catalyst with a p-n heterojunction is constructed, in which ZnIn 2 S 4 nanosheets are grown in situ on the surfaces of CoMn 2 O 4 hollow microcubes. Surprisingly, 10% CoMn 2 O 4 -ZnIn 2 S 4 (CMO-ZIS-10) exhibits a PHE rate of up to 11.04 mmol h −1 g −1 , which is approximately 3.6 times higher than that of pure ZnIn 2 S 4 . In addition, to maintain the excellent visible light absorption efficiency of ZnIn 2 S 4 nanosheets, the close-contact heterogeneous interface of CMO-ZIS enables easy separation and transfer of the carriers. Furthermore, the hollow structure increases the absorption efficiency of sunlight and provides more active sites, thus increasing the reactivity of photocatalyst. In this paper, we report a workable approach for building heterojunction photocatalysts powered by water splitting.
研究领域:
材料科学
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2015
·Vol. 5
·期 39
·30963-30969
·
IF 3.84
Long Ren,Jun Chen,Xiaoqing Wang,Mingjia Zhi,Junwei Wu,Xinhe Zhang
Facile synthesis of porous and hollow spinel materials is highly desirable for their extensive applications in energy storage fields. In this work, uniform and decentralized flower-like CoMn2O4 microspheres were synthesized and characterized for supercapacitor electrodes in neutral aqueous electrolyte. In this contribution, uniform microsphere precursors were firstly fabricated by a solvothermal method, followed by a low temperature calcination process for crystallization. A detailed study shows that the deionized (DI) water content plays an important role in the solvothermal process to optimize the morphology of the microspheres. In 1 M Na2SO4, the spinel electrode material has a working potential window as high as 1.1 V and a specific capacitance of 188 F g−1. Besides, the electrode material exhibits excellent cycling stability by retaining 93% of its original capacitance after 1000 cycles. Therefore, the flower-like microspheres of CoMn2O4 spinel are promising candidates for supercapacitor applications.
研究领域:
材料科学
·
能源存储
✓ 已验证
产品关联
DOI
高影响因子
LANGMUIR
·
2024
·
IF 3.7
Li Wang,Chunqiu Han,Xin Ying Kong,Liqun Ye,Yingping Huang
Advanced oxidation processes employing peroxymonosulfate (PMS) show significant promise for wastewater treatment. However, PMS activation typically relies on energy- and chemically intensive techniques due to its relatively low reactivity. Hence, the exploration of novel and energy-efficient approaches, such as the piezoelectric effect, for PMS activation is of paramount importance. Herein, we prepared a piezoelectric material (CoMn2O4) via a simple hydrothermal method followed by calcination. The degradation experiments of tetracycline (TC) demonstrated that CoMn2O4 exhibited excellent performance under ultrasound, the apparent rate constant k is 0.191 min–1, and its degradation rate reached 83.63% after 10 min. Piezo force microscopy (PFM) tests confirmed that CoMn2O4 exhibited a piezotronic effect under ultrasound. In situ electron paramagnetic resonance (in situ EPR) tests revealed that PMS could be activated to form hydroxyl radicals (•OH) and sulfate radicals (SO4•–) under ultrasound, which are active species for TC degradation. Consequently, CoMn2O4 effectively activated PMS into •OH and SO4•– active species, enabling the effective TC degradation. Moreover, biotoxicity experiments using germination tests showed that CoMn2O4 was capable of effectively degrading TC, thereby reducing environmental toxicity. This work not only provides mechanistic insights into piezoelectric material-activated PMS for pollutants degradation but also establishes a basis for the application of piezoelectric materials in pollutant degradation.
研究领域:
环境科学
·
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
FUEL
·
2025
·
IF 7.5
Yuchen Han,Yue Han,Yuxin Liu,Xingmeng Xu,Tingyang Li,Ruiyang Zhao,Jishu Han,Lei Wang
In the field of photocatalytic hydrogen production, the construction of p-n heterojunction was an effective strategy to solve the problem of high electron-hole pair recombination rate. In this paper, CoS 2 /CoMn 2 O 4 p-n heterojunction photocatalysts were successfully synthesized by loading CoS 2 nanoparticles on the surface of CoMn 2 O 4 nanocubes. Due to the strong light absorption performance, abundant active sites, and low photogenerated carrier recombination rate, CoS 2 /CoMn 2 O 4 exhibited significantly enhanced photocatalytic hydrogen production activity. Under light irradiation, the hydrogen production rate of CoS 2 /CoMn 2 O 4 could reach to 17.03 mmol/g within 3 h. This study provided a new idea for designing high-efficiency p-n heterojunction photocatalysts.
研究领域:
材料科学
·
能源科学
·
光催化技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2024
·
IF 5.8
Jianshan Yang,Yongjin Zou,Sanxia Zhang,Zongliang Yu
Transition metal oxides are widely used as electrode materials for supercapacitors due to their high capacitance and stability. Composite materials comprising two transition metal oxides may exhibit enhanced performance based on the properties of each material. In this study, a two-step hydrothermal method was used to fabricate CoMn 2 O 4 needle clusters loaded with Fe 2 O 3 structures. CoMn 2 O 4 serves as an excellent bimetallic oxide electrode material for supercapacitors and acts as a scaffold for loading Fe 2 O 3 particles, thereby further improving electrochemical performance. CoMn 2 O 4 @Fe 2 O 3 exhibited a high specific capacitance of 760 F g −1 at 1 A g −1 . The CoMn 2 O 4 @Fe 2 O 3 //GO asymmetric supercapacitor achieved a high energy density of 21.3 Wh kg −1 at 4021 W kg −1 and 36.3 Wh kg −1 at 803.4 W kg −1 , with a capacitance retention of 83 % after 10,000 cycles.
研究领域:
材料科学
·
能源存储
✓ 已验证
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2023
·
IF 6.7
Fanghui Cai,Chunyu Sun,Zhenzhen Sun,Yong Lai,Hanming Ding
Spinel-type bimetallic oxides have several potential applications in the catalytic degradation of organic wastewater due to their high catalytic activity and slow ion release rate caused by bimetallic synergy. In this study, sulfur-functionalized CoMn 2 O 4 (S-CoMn 2 O 4 ) was prepared as a Fenton-like catalyst by the sol–gel process, followed by calcination and sulfurization. The catalytic activity of CoMn 2 O 4 was significantly increased by the incorporation of sulfur. The S-CoMn 2 O 4 (5.00%) catalyst modified with 5.00% sulfur in atomic percentage exhibited the best catalytic performance. Typically, 30 mg/L of rhodamine B was removed in 18 min by using 0.20 g/L S-CoMn 2 O 4 (5.00%) and 0.16 g/L peroxymonosulfate. Singlet oxygen and sulfate radicals are the primary active species, according to the trapping agent experiments and EPR measurements. The incorporation of sulfur leads to the formation of abundant oxygen vacancies in CoMn 2 O 4 and sulfate groups bound on the surface of CoMn 2 O 4 , which promotes producing more active species. A synergism of Co and Mn ions in CoMn 2 O 4 and high electron transfer mobility are also responsible for the enhanced degradation performance of S-CoMn 2 O 4 (5.00%). This study provides a feasible solution for improving cobalt manganese oxide as a more effective and long-lasting Fenton-like catalyst for the degradation of organic contaminants.
研究领域:
环境科学
·
催化材料
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Lezhuo Li,Ruifeng Xu,Xu Zhang,Wenbo Wang,Bingjun Yang,Juan Yang,Tianhong Zhou,Pengjun Ma
Spinel-type AB 2 O 4 material has considerable potential as an efficient electrocatalyst in the oxygen evolution reaction (OER). However, developing spinel-type catalysts with higher catalytic activity still faces significant challenges. Herein, we reported an effective strategy to construct abundant oxygen vacancies into the CoMn 2 O 4 (CMO) catalyst using plasma etching, and those oxygen vacancies were capable of enhancing the OER activity of the CMO catalyst. The results showed that the etched CMO catalyst possessed an overpotential of 367 mV at a current density of 10 mA/cm 2 , and the change overpotential of the etched CMO catalyst was only about half compared to that of the pristine CMO catalyst in a 24-h stability test. The charge transfer ability and reaction kinetic characteristic of the etched CMO catalyst were dramatically improved. Furthermore, the mechanism of oxygen vacancies inducing enhancement of the OER catalytic activity in CMO catalysts has also been elucidated. This work successfully used a defect engineering strategy for modifying the spinel-type catalyst to enhance its OER activity, thereby providing a new idea and method for developing more efficient OER catalysts.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2024
·
IF 8.1
Yining Bao,Qingru Zeng,Shunyan Ning,Wei Zhao,Longfei Wang,Xinpeng Wang,Yuezhou Wei,Deqian Zeng
Developing effective heterojunction photocatalysts that efficiently separate charge carriers and improve light-harvesting capabilities is crucial in addressing energy and environmental issues. Herein, a unique nanocomposite photocatalyst is constructed by attaching CoMn 2 O 4 nanoparticles onto 2D CdS nanosheets for H 2 production and U(VI) reduction. The optimized 2% CoMn 2 O 4 /CdS nanocomposite showcases the highest photocatalytic H 2 production efficiency, 5.8 times higher than CdS nanosheets . Additionally, the U(VI) reduction rate constant of 2% CoMn 2 O 4 /CdS is 0.0192 min −1 , approximately 1.9 folds over the pristine CdS (0.0101 min −1 ). The exceptional photocatalytic performance toward photocatalytic H 2 evolution and U(VI) reduction reactions directly result from the electronic integration between CoMn 2 O 4 /CdS p-n heterojunction, facilitated by the efficient photoexcited charge separation. Feasible photocatalytic mechanisms are proposed through experimental analyses and theoretical calculations. This study provides a straightforward method for designing effective CdS-based heterostructured photocatalysts, contributing to the advancement of solar-to-H 2 conversion and environmental abetment.
研究领域:
材料科学
·
环境科学
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
MOLECULES
·
2024
·Vol. 29
·期 10
·2255
·
IF 4.2
Yan Cui,Zequan Zeng,Yaqin Hou,Shuang Ma,Wenzhong Shen,Zhanggen Huang
Noble metals have become a research hotspot for the oxidation of light alkanes due to their low ignition temperature and easy activation of C-H; however, sintering and a high price limit their industrial applications. The preparation of effective and low-noble-metal catalysts still presents profound challenges. Herein, we describe how a Ru@CoMn2O4spinel catalyst was synthesized via Ru in situ doping to promote the activity of propane oxidation. Ru@CoMn2O4exhibited much higher catalytic activity than CoMn2O4, achieving 90% propane conversion at 217 °C. H2-TPR, O2-TPD, and XPS were used to evaluate the catalyst adsorption/lattice oxygen activity and the adsorption and catalytic oxidation capacity of propane. It could be concluded that Ru promoted synergistic interactions between cobalt and manganese, leading to electron transfer from the highly electronegative Ru to Co2+and Mn3+. Compared with CoMn2O4, 0.1% Ru@CoMn2O4, with a higher quantity of lattice oxygen and oxygen mobility, possessed a stronger capability of reducibility, which was the main reason for the significant increase in the activity of Ru@CoMn2O4. In addition, intermediates of the reaction between adsorbed propane and lattice oxygen on the catalyst were monitored by in situ DRIFTS. This work highlights a new strategy for the design of a low-noble-metal catalyst for the efficient oxidation of propane.
研究领域:
催化
·
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2022
·
IF 9.136
Jixiang Xu,Yi Wang,Jun Wan,Lei Wang
In this work, carbon-doped CoMn 2 O 4 /Mn 3 O 4 (C-CoMnO) composite catalyst were prepared via calcining solvothermal product of Mn 2+ , Co 2+ , and 2-methylimidazole in air. The catalytic performance of activating peroxymonosulfate (PMS) for ciprofloxacin (CIP) degradation was discussed. The results showed that the 0.1 g L −1 C-2CoMnO could effectively activate PMS, resulting in 96.18% CIP was degraded within 60 min. The corresponding total organic carbon removal ratio and apparent rate constant were 81.33% and 0.043 min −1 , respectively. The influencing factors, such as Co/Mn molar ratios, calcination temperature, PMS concentration, solution pH, and coexisting ions were explored. The optimal catalytic system exhibited good recycling performance, wide pH adaptation and high resistance to salt interference. SO 4 ⋅ − , ⋅OH, and ⋅O 2 − -based radicals, as well as 1 O 2 and surface complexes-based nonradicals were participated in CIP degradation. The CIP degradation pathways were proposed. Density functional theory calculations (DFT) indicated that PMS was more easily activated via Co/Mn synergism. The doped carbon was also contributed to PMS activation via facilitating electron transfer. This study may shed light toward the synergistic effect of metal oxides in PMS activation.
研究领域:
环境科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Nano Materials
·
2022
·
IF 6.14
Li Luo,Rui Huang,Wei Hu,Zhaoshi Yu,Zhixin Tang,Leqi Chen,Yunhuai Zhang,Dan Zhang,Peng Xiao
Designing unique nanostructures and components for catalysts can promote the deep catalytic degradation of volatile organic compounds into CO2. Herein, a pyrolysis strategy for MOF-based oxides (Mn3[Co(CN)6]2·nH2O) was employed to successfully synthesize oxygen vacancy-enriched Mn–Co spinel oxides with hollow nanocube structures (denoted as MOF-CMO/400). Compared with CoMn2O4 nanoparticles prepared by the traditional precipitation method, MOF-CMO/400 presented a T90 of 209 °C for toluene catalytic oxidation, which was 38 °C lower than that of CoMn2O4 nanoparticles (247 °C). Especially in a high-temperature region, MOF-CMO/400 nanocubes possessed a narrower temperature range to achieve 100% toluene conversion than CoMn2O4 nanoparticles. The excellent catalytic activity of MOF-CMO/400 is mainly attributed to the three-dimensional hollow structure, more oxygen vacancy defects, longer Mn–O bonds, and abundant active oxygen species. Furthermore, MOF-CMO/400 nanocubes displayed good humidity resistance (above 5–10 vol % H2O). Therefore, the nanocatalyst with a distinctive structure and defects has great potential in industrial application for deep toluene oxidation.
研究领域:
环境化学
·
材料科学
·
催化
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2020
·
IF 5.774
Fujun Ren,Tong Wang,Haitao Liu,Desheng Liu,Rui Zhong,Changyu You,Weijun Zhang,Suyun Lv,Shanshan Liu,Hao Zhu,Lu Chang,Bo Wang
We proposed a new peroxymonosulfate (PMS) activator that the dispersed CoMn 2 O 4 nanoparticles embedded in nitrogen-doped reduced graphene oxide aerogel (CoMn 2 O 4 @N-rGA) with interlinked three-dimensional network via hydrothermal method for oxytetracycline (OTC) degradation. CoMn 2 O 4 @N-rGA and PMS (CoMn 2 O 4 @N-rGA/PMS) exhibited a high degradation rate of 91.3% within 20 min and a rapid catalytic degradation rate of 0.0729 min −1 . The radical pathway system had excellent effects on OTC degradation in a wide range of pH from 3.0 to 9.0 and an outstanding catalytic activity on actual pharmaceutical wastewater. It was attributed to dispersed CoMn 2 O 4 nanoparticles embed in nitrogen-doped reduced graphene oxide aerogel with interlinked three-dimensional network by Scanning electron microscope (SEM). The mechanism was hypothesized that PMS was activated to generate sulfate radical (SO 4 - ) and hydroxyl radicals ( OH), which could be confirmed via free radical quenching test and electron paramagnetic resonance (EPR) spectra. Finally, a flow-type setup based on the feedback mechanism with excellent effect on high concentration of OTC and actual pharmaceutical wastewater was designed for verifying the practical value of the system.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）