RSC Advances
·
2021
·Vol. 11
·期 46
·28949-28960
·
IF 3.361
Ze Lv,Zhen Chen,Qiang Yu,Wei Zhu,Hongjun You,Bangyao Chen,Zhaoyi Zheng,Yuanyuan Liu,Qi Hu
PbO2–Co3O4–MnO2 electrodes, used in the electrowinning industry and in the degradation of organic pollutants, have demonstrated an elevated performance through macroscopic electrochemical measurements. However, few reports have investigated localized electrochemical performance, which plays an indispensable role in determining the essential reasons for the improvement of the modified material. In this study, the causes of the increase in electrochemical reactivity are unveiled from a micro perspective through scanning electrochemical microscopy (SECM), X-ray diffraction (XRD), Raman microscopy (Raman), and X-ray photoelectronic energy spectroscopy (XPS). The results show that the increase of electrochemical reactivity of the modified electrodes results from two factors: transformation of the microstructure and change in the intrinsic physicochemical properties. Constant-height scanning maps indicate that the electrochemical reactivity of the modified electrodes is higher than that of the PbO2 electrode on the whole and high-reactivity areas are orderly distributed, coinciding with the observations from SEM and XRD. Thus, one of the reasons for the improvement of the modified electrode performance is the refinement of the microscopic morphology. The other reason is the surge of the oxygen vacancy concentration on the surface of the coating, which is supported by XRD, Raman and XPS. This finding is detected by the probe approach curve (PAC), which can quantitatively characterize the electrochemical reactivity of a substrate. Heterogeneous charge transfer rate constants of the modified electrode are 4–5 times higher than that of the traditional PbO2 electrode. This research offers some insight into the electrochemical reactivity of modified PbO2 electrodes from a micro perspective.
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
DALTON TRANSACTIONS
·
2023
·
IF 4
Fang Miao,Peng Cui,Tao Gu,Shijie Yu,Yuhong Zhao
The rational modification of electronic structures for catalytic active sites has been proved to be a promising strategy to facilitate efficient urea oxidation reaction (UOR). Herein, in this work, a well-defined nanosheets arrays catalyst of Ni(OH)2 doped with dual cation of Co and Mn on Ni foam (NF) (Co/Mn-Ni(OH)2) is synthesized though a simple hydrothermal process. Benefiting from the advantages of unique structures and modified binding strengths, it is found experimentally that the obtained Co/Mn-Ni(OH)2 catalyst only requires a potential of 1.38 V to deliver the current density of 100 mA cm-2 and a low Tafel slope of 35 mV dec-1, outperforming the single-component incorporated Ni(OH)2. Moreover, it has been shown the excellent stability for 25 h at the current density of 50 mA cm-2. Additionally, the first-principles calculations demonstrate that the co-incorporation of Co and Mn remarkably lowers the adsorption barrier of CO(NH2)2* on catalyst surface, and accelerates the dissociation CO(NH2)2* intermediate to CO* and NH* intermediate, which synergistically improves the UOR reaction kinetics. This work provides a well generic paradigm for designing advanced and effective catalysts toward UOR.
研究领域:
材料科学
·
电化学
·
催化科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INORGANIC CHEMISTRY COMMUNICATIONS
·
2024
·
IF 4.4
Li Chen,Junyou Wu,Haolan Huang,Xuefeng Zhang,Wenjing Tang,Jiahao He,Chao Zheng,Yingchun Yang
As a fourth quinolone drug, the efficient and rapid degradation of moxifloxacin (MOX) remain a rigorous problem. Peroxymonosulfate (PMS)-based oxidation method poses a promising application prospect for refractory antibiotic wastewater with an excellent degradation efficiency. Herein, the Co/Mn doped-carbon nanotube catalyst (CoMn@CNT) was successfully synthesized by a two-step pyrolysis method and applied to activate PMS for MOX degradation. The degradation efficiency of MOX could reach 89.7 % in 30 min with relatively low concentrations of PMS (100 mg/L) and CoMn@CNT (30 mg/L). The effects of catalyst dosage, PMS dosage, initial pH, reaction temperature, and co-existing ions for the degradation of MOX were investigated. The CoMn@CNT/PMS system possessed wide pH application range (3.0–11.0). Sulfate radical (SO 4 − ) was verified as the dominant reactive species responsible for degradation of MOX by quenching experiment. Finally, the possible MOX degradation pathways were also proposed. Overall, this study could provide some inspirations of the CoMn@CNT/PMS as a new system which applied to wastewater treatment of antibiotics.
研究领域:
环境科学
·
催化材料
·
废水处理
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产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2020
·
IF 3.573
Li Ma,Yu Qiu,Min Li,Dongxu Cui,Shuai Zhang,Dewang Zeng,Rui Xiao
Reverse water gas shift on the basis of chemical looping technology provides a viable method for efficiently converting CO2 to CO for hydrocarbons at moderate temperature (<750 °C). However, the commonly available oxygen carrier materials are insufficiently active because of the degrading effect at relatively low temperatures. In this paper, we present several Co, Mn codoped ferrites in search of oxygen carrier materials as highly active redox materials for a midtemperature chemical looping CO2 splitting process. The results show that up to ∼142.3 μmol·g–1·min–1 of CO production rate and ∼8.8 mmol·g–1 of CO yield are achieved by Mn0.2Co0.8Fe2O4 at 650 °C. The production rate and yield of CO of the codoped ferrites during the CO2 splitting process are comparable to those of the state-of-the-art perovskites which commonly contain rare-metal elements.
研究领域:
材料科学
·
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
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