Enhanced Photocatalytic Water Splitting by Plasmonic TiO₂–Fe₂O₃ Cocatalyst under Visible Light Irradiation

In this study, we introduce a plasmonic TiO₂–Fe₂O₃ cocatalyst photoelectrode to improve the water-splitting process. The absorption of incident photons and the separation rate of photogenerated electron–hole pairs are enhanced due to the broadband absorption and strong electric field of the composite formed from these two metal oxide semiconductors and plasmonic silver nanoparticles (Ag NPs). Plasmonic TiO₂–Fe₂O₃ cocatalyst photoelectrodes were fabricated using a precipitation and solution processing method. Under visible light irradiation, a photocurrent that is 20 times higher than that of pure Fe₂O₃ was observed using an optimized ratio of the plasmonic TiO₂–Fe₂O₃/Ag cocatalyst. The mechanism for this enhancement in the plasmonic cocatalyst system was investigated using different structural configurations of the photoelectrode. Both the crystallinity and absorption band edge of the TiO₂–Fe₂O₃ cocatalyst were characterized using X-ray diffraction (XRD) and ultraviolet–visible absorption spectroscopy (UV–vis). Furthermore, the spatial distribution of the photocurrent was investigated using this plasmonic cocatalyst system

Plasmon-Induced Hot Electrons on Mesoporous Carbon for Decomposition of Organic Pollutants under Outdoor Sunlight Irradiation

In this study, a 4 in. CMK-8-Nafion membrane was fabricated using three-dimensional cubic ordered mesoporous carbon CMK-8 blended with a Nafion polymer. Plasmon-resonance hot electrons and holes from Au nanoparticles (NPs) combined with this CMK-8-Nafion membrane resulted in the effective decomposition of methyl orange (MO) due to the synergetic work of hot carriers with mesoporous carbon; a sample of Au/CMK-8-Nafion exposed to outdoor sunlight radiation for 150 min successfully removed 97% of MO. Fourier transform infrared spectroscopy (FTIR) was employed to examine the generation of hydroxyl groups (OH−) during decomposition. Finally, the spatial distribution of hydroxyl groups was also investigated across the different coverage densities of plasmonic Au NPs

Additional file 1: of Photocatalytic Activities Enhanced by Au-Plasmonic Nanoparticles on TiO2 Nanotube Photoelectrode Coated with MoO3

Supporting information. (DOCX 1074 kb

High-Capacity Rechargeable Li/Cl₂ Batteries with Graphite Positive Electrodes

Developing new types of high-capacity and high-energy density rechargeable batteries is important to future generations of consumer electronics, electric vehicles, and mass energy storage applications. Recently, we reported ∼3.5 V sodium/chlorine (Na/Cl2) and lithium/chlorine (Li/Cl2) batteries with up to 1200 mAh g–1 reversible capacity, using either a Na or a Li metal as the negative electrode, an amorphous carbon nanosphere (aCNS) as the positive electrode, and aluminum chloride (AlCl3) dissolved in thionyl chloride (SOCl2) with fluoride-based additives as the electrolyte [Zhu et al., Nature, 2021, 596 (7873), 525–530]. The high surface area and large pore volume of aCNS in the positive electrode facilitated NaCl or LiCl deposition and trapping of Cl2 for reversible NaCl/Cl2 or LiCl/Cl2 redox reactions and battery discharge/charge cycling. Here, we report an initially low surface area/porosity graphite (DGr) material as the positive electrode in a Li/Cl2 battery, attaining high battery performance after activation in carbon dioxide (CO2) at 1000 °C (DGr_ac) with the first discharge capacity ∼1910 mAh g–1 and a cycling capacity up to 1200 mAh g–1. Ex situ Raman spectroscopy and X-ray diffraction (XRD) revealed the evolution of graphite over battery cycling, including intercalation/deintercalation and exfoliation that generated sufficient pores for hosting LiCl/Cl2 redox. This work opens up widely available, low-cost graphitic materials for high-capacity alkali metal/Cl2 batteries. Lastly, we employed mass spectrometry to probe the Cl2 trapped in the graphitic positive electrode, shedding light into the Li/Cl2 battery operation