Meng Lin

In recent years, flow batteries have emerged as a crucial technological solution for large-scale energy storage, leveraging their unique power-capacity decoupling characteristics and long cycle life to demonstrate significant potential in applications such as renewable energy integration and grid frequency regulation. Based on differences in electrolyte systems, mainstream flow battery technologies are primarily categorized into three types: all-vanadium redox flow batteries (VRFBs), iron-chromium redox flow batteries (ICFBs), and zinc-based redox flow batteries (ZRFBs). However, each of these technologies faces critical challenges in practical commercialization: VRFBs are constrained by cost pressures due to fluctuations in vanadium resource prices and relatively low energy efficiency; ICFBs require urgent solutions to issues such as hydrogen evolution side reactions at the negative electrode and the sluggish kinetic responses of the Cr³⁺/Cr²⁺ redox couple; while ZRFBs grapple with safety concerns such as zinc dendrite growth and morphology instability. To overcome these technical bottlenecks, extensive innovative research has been conducted in key materials (electrodes, ion-exchange membranes, electrolytes). Against this backdrop, this paper systematically reviews recent advances in the modification and optimization of flow battery technologies and conducts an extended discussion on the emerging organic redox flow batteries in recent years.

Petroleum oily sludge (OLS), a hazardous by-product of the petroleum industry, and high-alkali lignite (HAL), an underutilized low-rank coal, pose significant challenges to sustainable waste management and resource efficiency. This study systematically investigated the combustion behavior, reaction pathways, and gaseous-pollutant-release mechanisms across varying blend ratios, utilizing integrated thermogravimetric-mass spectrometry analysis (TG-MS), interaction analysis, and kinetic modeling. The key findings reveal that co-combustion significantly enhances the combustion performance compared to individual fuels. This is evidenced by reduced ignition and burnout temperatures, as well as an improved comprehensive combustion index. Notably, an interaction analysis revealed coexisting synergistic and antagonistic effects, with the synergistic effect peaking at a blending ratio of 50% OLS due to the complementary properties of the fuels. The activation energy was found to be at its minimum value of 32.5 kJ/mol at this ratio, indicating lower reaction barriers. Regarding gas emissions, co-combustion at a 50% OLS blending ratio reduces incomplete combustion products while increasing CO₂, indicating a more complete reaction. Crucially, sulfur-containing pollutants (SO₂, H₂S) are suppressed, whereas nitrogen-containing emissions (NH₃, NO₂) increase but remain controllable. This study provides novel insights into the synergistic mechanisms between OLS and HAL during co-combustion, offering foundational insights for the optimization of OLS-HAL combustion systems toward efficient energy recovery and sustainable industrial waste management.

Tannic acid contains a high density of catechol groups, which enable strong interactions with metal ions for the formation of adhesive assembly films. The metal-polyphenol structure formed by tannic acid with metal ions has the advantages of green environmental protection and strong adhesion. In this work, a tannic acid-iron film modified electrode was prepared by a one-step self-assembly method in which ferric chloride hexahydrate and tannic acid were used as reactants. Ultraviolet-visible absorption spectroscopy, scanning electron microscopy, X-ray photoelectron spectroscopy, and infrared spectroscopy were used to characterize the structure and morphology of the tannic acid-iron films. Differential pulse voltammetry was used to evaluate the electrochemical sensing performance of the tannic acid-iron film modified electrode towards dopamine. In the range of 450 μM-4 mM, the response current of the modified electrode has a good linear relationship with the dopamine concentration. An anti-interference test of the modified electrode was performed in an electrolyte containing ascorbic acid and uric acid. The electrode has good anti-interference performance. The successful construction of this sensor provides new insights into the research and design of dopamine electrochemical sensors.

Silver–bismuth composite-modified electrodes enhanced Cr²⁺/Cr³⁺ electrochemical activity and reversibility while suppressing hydrogen evolution. As anodes in Fe–Cr flow batteries, they improved its capacity, energy efficiency, and stability.

In this study, a simple and easy synthesis strategy to realize the modification of AuHgPt nanoalloy materials on the surface of ITO glass at room temperature is presented. Gold nanoparticles as templates were obtained by electrochemical deposition, mercury was introduced as an intermediate to form an amalgam, and then a galvanic replacement reaction was utilized to successfully prepare gold–mercury–platinum (AuHgPt) nanoalloys. The obtained alloys were characterized by scanning electron microscopy, UV–Vis spectroscopy, X-ray photoelectron spectroscopy and X-ray diffraction techniques. The electrochemical sensing performance of the AuHgPt-modified electrode for hydrogen peroxide was evaluated by cyclic voltammetry and chronoamperometry. Under light conditions, the AuHgPt-modified electrode exhibited a desirable current response in the detection of hydrogen peroxide due to the synergistic effect of the localized surface plasmon resonance effect inherent in gold nanoparticles, and this synergistic effect improved the sensitivity of hydrogen peroxide detection. Meanwhile, the AuHgPt-modified electrode also exhibited better stability and reproducibility, which makes the modified electrode have great potential for various applications in the field of electrochemical sensing.

Gold–mercury (AuHg) nanochains were successfully synthesized based on the tip effect of Au NRs. Chained gold–mercury–platinum (AuHgPt) nanoalloys were prepared by the galvanic replacement reaction (GRR) using AuHg nanochains as templates at room temperature and used to study the electrochemical properties in the hydrogen evolution reaction (HER). The morphologies, structures, compositions, and electronic effects of the AuHgPt nanochains were investigated, and the hydrogen evolution properties of the nanomaterials were electrochemically evaluated. The results of HER polarization curves in an alkaline solution showed that the overpotential required for the AuHgPt nanochains to reach a current density of 10 mA cm⁻² was only 23 mV and the Tafel slope was 47.72 mV dec⁻¹, both of which were lower than those of commercial Pt/C (27 mV, 54.11 mV dec⁻¹). Moreover, the loss of current density at a current density of 50 mA cm⁻² after a long period of 24 h was only 2.5 mV dec⁻¹. The loss of current density was only 2.8% after a long-duration test at 50 mA cm⁻². The synergistic interactions between the alloyed metals resulted in the nanochains exhibiting excellent HER electrocatalytic activity and stability. In addition, density functional theory (DFT) calculations were employed to analyze the Gibbs free energies related to water dissociation and H₂ desorption on different nanoalloys, along with the d-band center (ε_d) for these materials, which indicate that the enhanced water dissociation ability stems from an interaction between the intensified OH–Au and the diminished H–Pt bonds. This conclusion is supported by the observed increase in the average ε_d values of Au and Pt atoms within the AuHgPt nanoalloy.