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We synthesized a PbO2-coated electrode consisting of three layers, with Pb–0.6%Sb alloy as the substrate, α-PbO2 as the intermediate layer, and the outermost β-PbO2-Co3O4@C as the active layer for boosting OER activity.

High oxygen evolution overpotential and low corrosion resistance are the main challenges for oxygen evolution materials in acidic media. In this study, a novel composite material, Ti/TiO2-NTs/PbO2–CNTs–MnO2, with high oxygen evolution electrocatalytic activity was successfully prepared. First, TiO2 nanotubes (TiO2-NTs) were synthesized in situ on a Ti sheet via anodization and used as an intermediate layer. Subsequently, the adhesion and conductivity of the TiO2-NTs layer were increased through additional anodization, annealing, and electrochemical reduction. Finally, PbO2 was electrodeposited with a constant current in a lead acetate medium and doped with carbon nanotubes (CNTs) and MnO2. The surface morphology, phase composition, and electrochemical performance of the composite materials were investigated. Notably, in an acidic electrolyte (150 g/L H2SO4), Ti/TiO2-NTs/PbO2–CNTs–MnO2 exhibited good stability (30 h) and a low oxygen evolution overpotential of 410 mV at 50 mA/cm2, which is almost equivalent to that of precious metals (RuO2 and IrO2) and 499 mV lower than that of the industrial Pb–0.76 wt% Ag alloy. The outstanding performance is mainly attributed to the high aspect ratio of the TiO2-NT structure, synergistic effects of the active particles, and inherently good electrochemical properties of the active particles. Therefore, this study provides a new synthetic route for oxygen evolution materials in acidic media.

The high oxygen evolution overpotential of the Pb–Ag anode is one of the main reasons for the high energy consumption in Zn electrowinning. PbO2, owing to its high conductivity, good corrosion resistance and low cost, is widely used as an excellent coating material. In present research, a novel composite Ti/TiO2-NTs/PbO2 material was synthesized through a facile anodization, annealing, electrochemical reduction and galvanostatic deposition. The surface morphology, internal structure and the mechanisms of TiO2-NTs enhancing electrochemical performance were discussed. The results show that the self-organized high aspect ratio TiO2-NTs with diameter of ∼120 nm and length of ∼8 μm were obtained on Ti substrate. The Ti/TiO2-NTs/PbO2 composite material exhibits excellent oxygen evolution performance and good stability in Zn electrowinning simulation solution (50 g L−1 Zn2+, 150 g L−1 H2SO4) at 35 °C. Its oxygen evolution overpotential is only 630 mV under current density 50 mA cm−2, which is 332 m lower than that of Pb-0.76 wt% Ag (η = 962 mV) and only increases 22 mV after 5000 cycles of CV scanning. Its outstanding electrochemical performance is mainly ascribed to the introduction of TiO2-NTs in Pb(CH3COO)2 media since it refines the crystal grains, increases the electrochemical surface area, greatly reduces the charge transfer resistance (25.4 Ω cm2 to 2.337 Ω cm2) and enhances corrosion resistance. Therefore, the Ti/TiO2-NTs/PbO2 material prepared in Pb(CH3COO)2 medium may be an ideal anode for Zn electrowinning.

In the present work, a novel Pb-0.6%Sb/α-PbO2/β-PbO2 composite electrode with quantitatively phases of α or β-PbO2 was obtained by electrodeposition in methanesulfonic acid (MSA) and further investigated in novel flow battery. The physicochemical properties of lead dioxide were analyzed by anodic polarization curves, X-ray powder diffraction (XRD), scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS) and Tafel curves. Results showed that the selection of temperature ranges was found to cause a quantitative difference in the formation of α/β-PbO2 phases, as it made interval effects on the overpotential that was the primary control condition to affect transfer proces.The precise conditions of obtaining α or β-PbO2 phases by varying temperatures were confirmed and samples were prepared to be tested in long-period galvanostatic electrolysis. By comparing, the electrode (deposition time-α&β: 2 h&2 h) showed the best physicochemical properties, which could effectively improve the energy storage and extend the lifetime (63.6 h) compared with the traditional lead dioxide electrodes (24.5 h) in novel flow battery.

The high energy consumption during zinc electrowinning is mainly caused by the high overpotential of the oxygen evolution for Pb–Ag alloys with strong polarization. The preparation of new active energy-saving materials has become a very active research field, depending on the synergistic effects of active particles and active oxides. In this research, a composite material, α(β)-PbO2, doped with Co3O4 and CNTs on the porous Ti substrate was prepared via one-step electrochemical deposition and the corresponding electrochemical performance was investigated in simulated zinc electrowinning solution. The composite material showed a porous structure, finer grain size and larger electrochemical surface area (ECSA), which indicated excellent electrocatalytic activity. Compared with the Pb–0.76 wt% Ag alloy, the overpotential of oxygen evolution for the 3D-Ti/PbO2/Co3O4–CNTs composite material was decreased by about 452 mV under the current density of 500 A m−2 in the simulated zinc electrowinning solution. The decrease in the overpotential of oxygen evolution was mainly ascribed to the higher ECSA and lower charger transfer resistance. Moreover, it showed the lowest self-corrosion current density of 1.156 × 10−4 A cm−2 and may be an ideal material for use in zinc electrowinning.

The conventional Pb-Ag alloy possesses a high oxygen evolution reaction overpotential, poor stability, and short service life in acidic solutions, making it an unsuitable sort of anode material for the zinc electrowinning process. Therefore, a layered carbon-covered cobalt tetroxide (Co

The oxygen evolution reaction kinetics in industrial zinc electrowinning is sluggish, resulting in low electrocatalytic activity and substantial energy expenditure (about one-third of energy was wasted due to the strong polarization effect). Herein, the paper described a core-shell structured MnCo

In the present work, a novel Pb-0.6%Sb/α-PbO2/β-PbO2-MnO2 composite electrode with high electrocatalytic activity was obtained by electrodeposition in methanesulfonic acid and further investigated in the electrochemical degradation of alizarin yellow R(AYR) wastewater. The selection of temperature ranges was found to cause a quantitative difference in the formation of α/β-PbO2 phases. In this way, both phases were simultaneously electrodeposited in the same methanesulfonic acid, and electrodes with corresponding proportions of phases were fabricated. Furthermore, performance tests indicated that composite electrodes with the most appropriate corresponding proportions of phases co-deposited with proper amount of MnO2 could obviously improve the COD removal efficiency and degradation efficiency of AYR to 78.1% and 80.3%. They also showed commendable recyclability and fine economic applicability. Ultimately, the paper proposed a proper electrocatalytic degradation pathway of AYR based on the identification of the major intermediate products. The results proved that MnO2-co-doped composite electrodes had more promising application potential in the electrocatalytic degradation of AYR wastewater.

The high oxygen evolution overpotential of the Pb-Ag anode is one of the main reasons for the high energy consumption in Zn electrowinning. PbO

In industrial zinc electrowinning, the anodic oxygen evolution reaction (OER) has sluggish kinetics leading to ultrahigh overpotential and energy consumption. Herein, a sandwich-like MnCo2O4 modifying PbO2 composite electrode was fabricated via chemical-bath-deposition and electrodeposition. Consequently, the synthesized PbO2 electrode exhibits low Tafel slope of 0.17 V per decade and an operating potential of 1.68 V vs. SCE for 500 A m−2 in a simulated solution containing 150 g L−1 H2SO4 and 50 g L−1 Zn2+. Compared with traditional Pb-0.76Ag alloy, the overpotential at 500 A m−2 decreased by 357 mV, which ascribe to the incorporation of MnCo2O4 minoring crystal grain size and charge transfer resistance and enlarging active surface area. Furthermore, the composite electrode shows robust durability as long as 95 h at 15,000 A m−2 in 0.5 M H2SO4 electrolyte. Hence, this study offers a facile synthesis route to prepare composite electrodes for zinc electrowinning and provides deep insight into the relationship among modifying substances, microstructures, and electrocatalytic activity.

The high energy consumption during zinc electrowinning is mainly caused by the high overpotential of the oxygen evolution for Pb-Ag alloys with strong polarization. The preparation of new active energy-saving materials has become a very active research field, depending on the synergistic effects of active particles and active oxides. In this research, a composite material, α(β)-PbO

The histone lysine demethylase KDM5 family is implicated in normal development and stem cell maintenance by epigenetic modulation of histone methylation status. Deregulation of the KDM5 family has been reported in various types of cancers, including hematological malignancies. However, their transcriptional regulatory roles in the context of leukemia remain unclear. Here, we find that KDM5B is strongly expressed in normal CD34+ hematopoietic stem/progenitor cells and chronic myeloid leukemia (CML) cells. Knockdown of KDM5B in K562 CML cells reduced leukemia colony-forming potential. Transcriptome profiling of KDM5B knockdown K562 cells revealed the deregulation of genes involved in myeloid differentiation and Toll-like receptor signaling. Through the integration of transcriptome and ChIP-seq profiling data, we show that KDM5B is enriched at the binding sites of the GATA and AP-1 transcription factor families, suggesting their collaborations in the regulation of transcription. Even though the binding of KDM5B substantially overlapped with H3K4me1 or H3K4me3 mark at gene promoters, only a small subset of the KDM5B targets showed differential expression in association with the histone demethylation activity. By characterizing the interacting proteins in K562 cells, we discovered that KDM5B recruits protein complexes involved in the mRNA processing machinery, implying an alternative epigenetic action mediated by KDM5B in gene regulation. Our study highlights the oncogenic functions of KDM5B in CML cells and suggests that KDM5B is vital to the transcriptional regulation via multiple epigenetic mechanisms.

In this paper, a Co3O4- and CNT-doped 3D PbO2 electrode was fabricated through galvanostatic electrodeposition in a Pb(Ac)2-NH2SO3H solution, and the electrochemical properties were systematically investigated in a zinc electrolyte. The XRD results show that the deposit is a mixture of an α + β phase (a dominant β-PbO2 phase with a minor α-PbO2 phase present), and the SEM images show that Co3O4 and CNT have been simultaneously deposited with PbO2. The 3D-Ti/PbO2-(4 g·L−1) Co3O4-(0.4 g·L−1) CNT electrode exhibits a voltammetric charge 5 times larger than that of the 3D-Ti/PbO2 electrode, which indicates outstanding electrocatalytic activity. The oxygen evolution reaction overpotential and cell voltage are only 394 mV and 3.74 V at 500 A∙m−2, respectively. In addition, the obtained electrode showed a high current efficiency of 95.3% and a service life of 26 h under a current density of 20,000 A∙m−2. Hence, this study offers a facial synthesis route to prepare composite electrodes for zinc electrowinning and provides deep insight into the relationship among doping substances, microstructures and electrocatalytic activity.

In the present work, nucleation mechanism, preparation conditions, performance testing and application simulation of lead dioxide coating materials prepared by electrodeposition from methanesulfonic acid were studied to improve anodic process in zinc electrowinning process. Phase growth and transformation of lead dioxide were analyzed by anodic polarization curves, X-ray powder diffraction, scanning electron microscopy SEM, electrochemical impedance spectroscopy (EIS) and Tafel curves. The selection of temperature ranges was found to cause a quantitative difference in the formation of α/β-PbO2 phases, as it made interval effects on the overpotential that was the primary control condition to affect transfer process, while without changing the reaction mechanism apparently. In this way, the precise conditions of obtaining α- or β-PbO2 phases by varying temperatures was confirmed and samples were selected to be tested in long-period galvanostatic electrolysis, electrode (deposition time-α&β: 2 h&2 h) showed the best physicochemical properties and could effectively extend the lifetime (70.4 h) compared with the traditional lead dioxide electrodes (32.3 h) in zinc electrowinning.