The integration of intermittent renewable energy sources into the energy supply has driven the need for large-scale energy storage technologies. Vanadium redox flow batteries (VRFBs) are considered promising due to their long lifespan, high safety, and flexible design. However, the graphite felt (GF) electrode, a critical component of VRFBs, faces challenges due to the scarcity of active sites, leading to low electrochemical activity. Herein, we developed a bismuth nanoparticle uniformly modified graphite felt (Bi-GF) electrode using a bismuth oxide-mediated hydrothermal pyrolysis method. The Bi-GF electrode demonstrated significantly improved electrochemical performance, with higher peak current densities and lower charge transfer resistance than those of the pristine GF. VRFBs utilizing Bi-GF electrodes achieved a charge-discharge capacity exceeding 700 mAh at 200 mA/cm2, with a voltage efficiency above 84%, an energy efficiency of 83.05%, and an electrolyte utilization rate exceeding 70%. This work provides new insights into the design and development of efficient electrodes, which is of great significance for improving the efficiency and reducing the cost of VRFBs.
The oxidative dehydrogenation of propane (ODHP) catalyzed by oxygen offers several advantages, including resistance to carbon deposition and low energy consumption. However, achieving high propylene selectivity at industrially relevant conversions remains challenging, as existing catalysts typically require temperatures exceeding 500 °C, promoting over-oxidation to COx. In this study, we developed a NiO nanoparticle-decorated graphitic carbon nitride catalyst (NiO@CN-600) via thermal polymerization–oxidation for photo-thermal synergistic ODHP. At 430 °C, thermal catalysis achieved a propane conversion of 14%. Remarkably, introducing light irradiation boosted conversion to 24%, a 10% increase. Further experimental results reveal that the photo-thermal synergistic catalysis can be described by the following mechanism: initial thermal energy provides sufficient activation energy, enabling the reaction to overcome the energy barrier and proceed smoothly. Simultaneously, the introduction of light energy enhances the activity of lattice oxygen, making it more likely to detach from the lattice and form oxygen vacancies, which in turn boosts the efficiency of the oxidation reaction on the catalyst surface.
The hydrogen economy, as an emerging paradigm for sustainable energy, relies on efficient hydrogen oxidation (HOR) and hydrogen evolution reactions (HER). These reactions require effective catalysts to enhance reaction kinetics and reduce costs. Platinum (Pt) is widely used but faces issues such as high cost and CO poisoning. Non-precious metal catalysts, particularly Ni-based alloys, are being explored as viable alternatives. This study introduces a ternary MoWNi alloy catalyst synthesized via microwave-assisted methods and annealing. The MoWNi alloy catalyst achieves a current density of 3.5 mA·cm−2 at an overpotential of 100 mV in HOR and requires only 25 mV overpotential to reach a current density of 10 mA·cm−2 in HER, making it comparable to commercial 20% Pt/C catalysts. Notably, the catalyst also exhibits superior stability and resistance to CO toxicity. These findings underscore the potential of MoWNi alloy catalysts in advancing hydrogen-based energy systems.