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Contact Electro-Catalysis (CEC) using commercial dielectric materials in contact-separation cycles with water can trigger interfacial electron transfer and induce the generation of reactive oxygen species (ROS). However, the inherent hydrophobicity of commercial dielectric materials limits the effective reaction sites, and the generated ROS inevitably undergo self-combination to form hydrogen peroxide (H 2 O 2 ). In typical CEC systems, H 2 O 2 does not further decompose into ROS, leading to suboptimal reaction rates. Addressing the generation and activation of H 2 O 2 is therefore crucial for advancing CEC. Here, we synthesized a catalyst by loading the dielectric material polytetrafluoroethylene (PTFE) onto ZSM-5 (PTFE/ZSM-5, PZ for short), achieving uniform dispersion of the catalyst in water for the first time. The introduction of an Fe III -initiated self-cycling Fenton system (SF-CEC), with the synergistic effects of O 2 activation and Fe III -activated H 2 O 2 , further enhanced ROS generation. In the Fe III -initiated SF-CEC system, the synergistic effects of ROS and protonated azo dyes enabled nearly 99 % degradation of azo dyes within 10 minutes, a sixfold improvement compared to the CEC system. This represents the fastest degradation rate of methyl orange dye induced by ultrasound to date. Without extra oxidants, this system enabled stable dissolution of precious metals in weakly acidic solutions at room temperature, achieving 80 % gold dissolution within 2 hours, 2.5 times faster than similar CEC systems. This study also corrects the unfavorable perception of CEC applications under acidic conditions, providing new insights for the fields of dye degradation and precious metal recovery., (© 2024 Wiley-VCH GmbH.)

The conversion of methane under ambient conditions has attracted significant attention. Although advancements have been made using active oxygen species from photo- and electro- chemical processes, challenges such as complex catalyst design, costly oxidants, and unwanted byproducts remain. This study exploits the concept of contact-electro-catalysis, initiating chemical reactions through charge exchange at a solid-liquid interface, to report a novel process for directly converting methane under ambient conditions. Utilizing the electrification of commercially available Fluorinated Ethylene Propylene (FEP) with water under ultrasound, we demonstrate how this interaction promote the activation of methane and oxygen molecules. Our results show that the yield of HCHO and CH 3 OH can reach 467.5 and 151.2 μmol ⋅ g cat -1 , respectively. We utilized electron paramagnetic resonance (EPR) to confirm the evolution of hydroxyl radicals (⋅OH) and superoxide radicals (⋅OOH). Isotope mass spectrometry (MS) was employed to analyze the elemental origin of CH 3 OH, which can be further oxidized to HCHO. Additionally, we conducted density functional theory (DFT) simulations to assess the reaction energies of FEP with H 2 O, O 2 , and CH 4 under these conditions. The implications of this methodology, with its potential applicability to a wider array of gas-phase catalytic reactions, underscore a significant advance in catalysis., (© 2024 Wiley-VCH GmbH.)

Perfluoroalkyl substances (PFASs) are persistent and toxic to human health. It is demanding for high-efficient and green technologies to remove PFASs from water. In this study, a novel PFAS treatment technology was developed, utilizing polytetrafluoroethylene (PTFE) particles (1-5 μm) as the catalyst and a low frequency ultrasound (US, 40 kHz, 0.3 W/cm 2 ) for activation. Remarkably, this system can induce near-complete defluorination for different structured PFASs. The underlying mechanism relies on contact electrification between PTFE and water, which induces cumulative electrons on PTFE surface, and creates a high surface voltage (tens of volts). Such high surface voltage can generate abundant reactive oxygen species (ROS, i.e., O 2 ⋅ - , HO⋅, etc.) and a strong interfacial electrostatic field (IEF of 10 9 ~10 10  V/m). Consequently, the strong IEF significantly activates PFAS molecules and reduces the energy barrier of O 2 ⋅ - nucleophilic reaction. Simultaneously, the co-existence of surface electrons (PTFE*(e - )) and HO⋅ enables synergetic reduction and oxidation of PFAS and its intermediates, leading to enhanced and thorough defluorination. The US/PTFE method shows compelling advantages of low energy consumption, zero chemical input, and few harmful intermediates. It offers a new and promising solution for effectively treating the PFAS-contaminated drinking water., (© 2024 Wiley‐VCH GmbH.)