Use of metal oxides for the adsorptive removal of toxic organic pollutants

Certain organophosphorus molecules are infamous due to their use as highly toxic nerve agents. The filtration materials currently in common use for protection against chemical warfare agents were designed before organophosphorus compounds were used as chemical weapons. A better understanding of the surface chemistry between simulant molecules and the individual filtration-material components is a critical precursor to the development of more effective materials for filtration, destruction, decontamination, and/or sensing of nerve agents. Here, we report on the surface adsorption and reactions of a sarin simulant molecule, dimethyl methylphosphonate (DMMP), with cupric oxide surfaces. In situ ambient pressure X-ray photoelectron and infrared spectroscopies are coupled with density functional calculations to propose mechanisms for DMMP decomposition on CuO. We find extensive room temperature decomposition of DMMP on CuO, with the majority of decomposition fragments bound to the CuO surface. We observe break...

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Spectroscopic and Computational Investigation of Room-Temperature Decomposition of a Chemical Warfare Agent Simulant on Polycrystalline Cupric Oxide

Zr-doped-TiO 2 loaded glass fiber (ZT/GF) composite photocatalysts with different Zr/Ti ratios were prepared with a sol–gel process. Zr 4 + can replace Ti 4 + in the TiO 2 lattice, which is conducive to forming the anatase phase and reducing the calcination temperature. The glass fiber carrier was responsible for better dispersion and loading of Zr-doped-TiO 2 particles, improving the applicability of the Zr-doped-TiO 2 . The ZT/GF photocatalysts were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FT-IR), ultraviolet–visible spectroscopy (UV–vis) and Barrett–Joyner–Halenda (BJH). The performance of photocatalysts with different loading was evaluated in formaldehyde degradation under visible light at room temperature. ZT/GF0.2 exhibited the highest activity, with a formaldehyde removal rate as high as 95.14% being observed, which is better than that of the photocatalyst particles alone. The stability of the catalyst was also tested, and ZT/GF exhibited excellent catalytic performance with 94.38% removal efficiency, even after seven uses.

Highly efficient Zr doped-TiO2/glass fiber photocatalyst and its performance in formaldehyde removal under visible light

The decontamination of chemical warfare agents (CWAs) from structures, environmental media and even personnel has become an area of particular interest in recent years due to increased homeland security concerns. This article reviews applications of catalytic methods used for decontamination of CWAs. Most attention was given to the following methods: thermocatalysis, photocatalysis and enzyme catalysis among the many methods of catalytic CWA decomposition. Unfortunately, there are not enough data obtained with real CWAs due to the difficulty in handling, so we have described also data available for CWAs simulants. These methods can be useful for decontamination systems that can reduce the damage caused by possible terrorism.

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Thermal and catalytic methods used for destruction of chemical warfare agents

In this study, a series of Na–Zr/TiO2 photocatalysts with different Na contents were synthesized via the sol–gel process. The characterization of the materials showed that Na addition facilitates the maintenance of anatase and excess Na led to particle size increases because of the formation of Na2Ti3O7. The XPS results suggested that Na loading can increase the number of oxygen vacancies, leading to more abundant surface hydroxyl groups. The enhanced photocatalytic activities under visible light irradiation can be attributed to a decreasing band gap and increasing oxygen vacancies. The efficiency of the Na–Zr/TiO2 samples was investigated by the degradation of formaldehyde under visible light. A high degradation rate of formaldehyde of approximately 96.6% was obtained with 2.5 mol % Na added to the Zr/TiO2 samples.

Impact of Zr-Doped TiO2 Photocatalyst on Formaldehyde Degradation by Na Addition

Decontamination of Chemical Warfare Agents on sensitive equipment materials using Zr4+ and Ge4+ co-doped TiO2 and hydrofluoroether suspension

Owing to the high structural designability and functional tunability, covalent organic frameworks (COFs) have emerged as a promising platform for designing brilliant photocatalyst candidates. However, their photocatalytic performances are still...

Rational design of a phenothiazine-based donor-acceptor covalent organic framework for enhanced photocatalytic oxidative coupling of amines and cyclization of thioamides

Li-Kun Chen

Papers

Decontamination of Chemical Warfare Agents on sensitive equipment materials using Zr4+ and Ge4+ co-doped TiO2 and hydrofluoroether suspension

Rational design of a phenothiazine-based donor-acceptor covalent organic framework for enhanced photocatalytic oxidative coupling of amines and cyclization of thioamides

Theoretical Study of VX Hydrolysis Mechanism Catalyzed by Phosphotriesterase Mutant H254R

Degradation of chemical warfare agents by nickel doped titanium dioxide powders: Enhanced surface activity

Degradation of Chemical Warfare Agents by Germanium-doped Nanosized TiO2 under Simulated Sunlight Irradiation