Reusable surface‐enhanced Raman scattering (SERS) substrates with integrated self‐cleaning capability are highly desirable for trace molecular detection, as they can reduce substrate consumption, minimize signal interference from residual analytes, and improve the practicality of repeated measurements. In this study, Ag/GO/MoO3 composite substrates were fabricated for the sensitive detection of rhodamine 6G (R6G). The Ag nanoparticles provided abundant electromagnetic “hot spots” for Raman signal enhancement, while graphene oxide facilitated molecular adsorption and interfacial charge transfer. More importantly, the incorporation of photocatalytically active MoO3 endowed the substrate with self‐cleaning functionality under xenon‐lamp irradiation. The optimized Ag/GO/MoO3 SERS substrate exhibited excellent detection sensitivity toward R6G, achieving a detection limit as low as 10−12 M and an estimated EFof approximately 2.05 × 106. During photocatalytic cleaning, approximately 75% of the MB signal was removed within the first 20 min, and the characteristic Raman peaks became undetectable after 40 min of irradiation. Real‐time monitoring further demonstrated that the substrate could effectively remove adsorbed dye molecules and maintain good self‐cleaning performance over three successive cycles. The self‐cleaning behavior and the associated adsorption–photocatalytic degradation process were investigated. These results demonstrate that Ag/GO/MoO3 is a recyclable and self‐cleaning SERS substrate with promising potential for repeated trace detection applications.
Hydrogen is a promising green alternative to fossil fuels. However, the scarcity and high cost of platinum group metals pose a major economic challenge to the large‐scale production of hydrogen. To address this issue, we investigated a novel, noble‐metal‐free NiTiCu thin‐film metallic glass (TFMG). This film was successfully deposited onto a copper substrate via magnetron sputtering to serve as a cathode for the hydrogen evolution reaction (HER). The surface was characterized structurally and electrochemically for its ability to undergo HER in both acidic and alkaline environments. Ni 8.46 Ti 5.52 Cu 86.01 film showed satisfactory performance in the alkaline environment compared with pure Cu and maintained its stability for 21 h, as confirmed by the chronopotentiometry test. Its η onset and η 10 were 193 and 360 mV versus RHE in alkaline media, respectively, while its Tafel slope was calculated to be 127 mV dec −1 . The prepared coating noticeably increased the electrochemically active surface area of the Cu substrate from 24.25 to 227.5 cm 2 . Moreover, the satisfactory hydrophobicity of the surface, with a water contact angle of 104.1°, enhanced water‐splitting efficiency by facilitating bubble desorption from the surface. This study provides insight into the HER of NiTiCu‐based TFMGs and identifies the key factors that enhance their efficiency.
While playing a pivotal role in battery performance, affecting energy density, cycling life, and safety, the anodic current collector of lithium‐ion batteries (LIBs) is largely overlooked in the literature. Copper, the dominant material for anode current collectors, contributes to approximately 8.1% of the battery weight yet does not participate in energy storage, limiting overall energy density. Reducing weight and thickness of copper foils optimizes the gravimetric energy density of LIBs, but challenges in processability hinder the production of thinner foils. This study presents a novel fabrication method to integrate multi‐walled carbon nanotubes (MWCNTs) inside copper to potentially develop a lightweight, thin, and efficient current collector. The composite is fabricated by coating MWCNTs with polydopamine (PDA), spray‐depositing onto an industrial support layer, and infilling the porous nanostructure via copper electroplating. This process enables the production of composite foils with surface areas up to 400 cm2—potentially addressing industry needs for scalable, high‐performance current collectors—and achieves a thickness of 4.5 µm and density of 6.4 g cm−3. Moreover, electrochemical performance of the material as anode current collector in half‐cell battery architecture showed improvements in gravimetric capacity of up to 7.3%, with stable cycling and efficiency.
Electrochemical reduction of CO 2 to multicarbon products is widely regarded as pivotal to the sustainable production of fuels and value‐added chemicals. A detailed understanding of the CO dimerization mechanism on Cu‐based metal catalysts is indispensable for developing highly active reaction systems; however, most previous studies have focused exclusively on the CC bond formation step. Herein, we comprehensively investigate the CO dimerization process by explicitly accounting for the surface diffusion of CO molecules using first‐principles calculations. The activation barriers for CO migration from an atop site to a bridge site and from a bridge site to a hollow site are 0.040 and 0.061 eV, respectively, at the Cu(100) surface. These values are approximately one order of magnitude smaller than the activation barrier for the CC bond formation step (0.469 eV), indicating that surface diffusion is energetically facile. Therefore, surface diffusion is required to generate neighboring CO species prior to CC coupling, but it does not appreciably contribute to the reaction activation energy. Additional calculations on heterometal‐doped Cu surfaces showed that the CO migration barriers remained much smaller than the CC bond‐formation barriers, indicating that the reaction activation energy is also governed mainly by CC bond formation in Cu‐alloy systems.
