Rational Design and Preparation of Pt-LDH/CeO2 Catalyst for High-Efficiency Photothermal Catalytic Oxidation of Toluene

Photothermal Catalytic Degradation of VOCs: Mode, System and Application

Human production and living processes emit excessive VOCs into the atmosphere, posing significant threats to both human health and the environment. The photothermal catalytic oxidation process is an organic combination of photocatalysis and thermocatalysis. Utilizing photothermal catalytic degradation of VOCs can achieve better catalytic activity at lower temperatures, resulting in more rapid and thorough degradation of these compounds. Photothermal catalysis has been increasingly applied in the treatment of atmospheric VOCs due to its many advantages. A brief introduction on the three modes of photothermal catalysis is presented. Depending on the main driving force of the reactions, they can be categorized into thermal-assisted photocatalysis (TAPC), photo-assisted thermal catalysis (PATC) and photo-driven thermal catalysis (PDTC). The commonly used catalyst design methods and reactor types for photothermal catalysis are also briefly introduced. This paper then focuses on recent developments in specific applications for photothermal catalytic oxidation of different types of VOCs and their corresponding principles. Finally, the problems and challenges facing VOC degradation through this method are summarized, along with prospects for future research.

Pd anchored to layered double hydroxide modified with chitosan and Echinophora platyloba extract as a nanocatalyst for the formylation of aryl iodides with formic acid

The novel Zn-Cu-Al layered double hydroxide (LDH) encapsulated within a chitosan/glutaraldehyde matrix, designated as LDH@Cs/G@Pd, was synthesized through simplified methodologies for the preparation of aromatic aldehyde derivatives. Formic acid served as the carbon monoxide source and hydrogen donor, while chitosan/glutaraldehyde acted as the linking agent between the substrate and palladium nanoparticles, with Echinophora platyloba extract functioning as the reducing agent for palladium. The characterization of LDH@Cs/G@Pd was conducted using a variety of analytical techniques, including Fourier-transform infrared spectroscopy (FT-IR), energy-dispersive X-ray spectroscopy (EDS), field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) surface area analysis, and inductively coupled plasma optical emission spectroscopy (ICP-OES). The results indicate that the catalyst has been successfully synthesized and Showed promising characteristics for its intended application. Afterward, the catalyst was utilized to Synthesize aromatic aldehydes. The catalyst developed in this study demonstrated a synthesis yield of approximately 95 % for aromatic aldehydes, confirming its potential as an effective candidate for industrial applications.

Preparation of hollow double-layer Pt@CeO2 nanospheres as oxidase mimetics for the colorimetric-fluorescent-SERS triple-mode detection of glutathione in serum

Glutathione (GSH) is an essential antioxidant in the human body, but its detection is difficult due to the interference of complex components in serum. Herein, hollow double-layer Pt@CeO2 nanospheres were developed as oxidase mimetics, and the light-assisted oxidase mimetics effects were found. The oxidase activity was enhanced significantly by utilizing the synergistic effect of Schottky junction and the localized surface plasmon resonance (LSPR) of Pt under UV light. A novel GSH colorimetric-fluorescent-SERS sensing platform was established, with the sensing performance notably boosted by using the light-assisted oxidase mimetics effects. This platform boasts an exceptionally low detection limit (LOD) of 0.084 μM, while the detection time was shortened from 10 min to just 2 min. The anti-interference detection with high recovery rate (96.84%-107.4 %) in real serum made it be promising for practical application.

Urea-H2O2 defect engineering of δ-MnO2 for propane photothermal oxidation: Structure-activity relationship and synergetic mechanism determination

Photothermal catalysis has an advantage in effective and economical elimination technology of volatile organic compounds (VOCs) in the ascendant. Herein, various surface defect engineering routes were adopted to enhance the low-temperature propane oxidation of δ-MnO₂. Compared to reducing etchants urea and vitamin C, δ-MnO₂ treated with urea - H₂O₂ exhibited an excellent thermal (T₉₀ = 240 ℃) and photothermal (T₉₀ = 196 ℃) activities of propane oxidation. Urea - H₂O₂ treatment provided high concentration of Mn⁴⁺ and surface-active oxygen (Mn⁴⁺-O_sur) species as surface-active sites, and produced numerous oxygen vacancies to improve charge separation and superoxide species generation capacity. Thus, the photothermal conversion efficiency and low-temperature reducibility were remarkably enhanced. Furthermore, the photothermal synergistic catalytic mechanism was proposed based on in-situ diffuse reflectance infrared Fourier transform spectroscopy and control experiments. The strategy here offered insight into the rational design of efficient transition catalysts, and in-depth understanding of the photothermal catalytic VOCs removal mechanism.