Rapid removal and decomposition of gaseous acetaldehyde by the thermo- and photo-catalysis of gold nanoparticle-loaded anatase titanium(IV) oxide

The Superiority of TiO2 Supported on Nickel Foam over Ni-Doped TiO2 in the Photothermal Decomposition of Acetaldehyde

Acetaldehyde decomposition was performed under heating at a temperature range of 25-125 °C and UV irradiation on TiO2 doped by metallic Ni powder and TiO2 supported on nickel foam. The process was carried out in a high-temperature reaction chamber, "The Praying MantisTM", with simultaneous in situ FTIR measurements and UV irradiation. Ni powder was added to TiO2 in the quantity of 0.5 to 5.0 wt%. The photothermal measurements of acetaldehyde decomposition indicated that the highest yield of acetaldehyde conversion on TiO2 and UV irradiation was obtained at 75 °C. The doping of nickel to TiO2 did not increase its photocatalytic activity. Contrary to that, the application of nickel foam as a support for TiO2 appeared to be highly advantageous because it increased the decomposition of acetaldehyde from 31 to 52% at 25 °C, and then to 85% at 100 °C in comparison with TiO2 itself. At the same time, the mineralization of acetaldehyde to CO2 doubled in the presence of nickel foam. However, oxidized nickel foam used as support for TiO2 was detrimental. Most likely, different mechanisms of electron transfer between Ni-TiO2 and NiO-TiO2 occurred. The application of nickel foam greatly enhanced the separation of free carriers in TiO2. As a consequence, high yields from the photocatalytic reactions were obtained.

Effective Removal of Acetaldehyde Using Piperazine/Nitric Acid Co-Impregnated Bead-Type Activated Carbon

Acetaldehyde (CH₃CHO) in the atmosphere is associated with adverse health effects. Among the various options for use in removing CH₃CHO, adsorption is often employed because of its convenient application and economical processes, particularly when using activated carbon. In previous studies, the surface of activated carbon has been modified with amines to remove CH₃CHO from the atmosphere via adsorption. However, these materials are toxic and can have harmful effects on humans when the modified activated carbon is used in air-purifier filters. Therefore, in this study, a customized bead-type activated carbon (BAC) with surface modification options via amination was evaluated for removing CH₃CHO. Various amounts of non-toxic piperazine or piperazine/nitric acid were used in amination. Chemical and physical analyses of the surface-modified BAC samples were performed using Brunauer-Emmett-Teller measurements, elemental analyses, and Fourier transform infrared and X-ray photoelectron spectroscopy. The chemical structures on the surfaces of the modified BACs were analyzed in detail using X-ray absorption spectroscopy. The amine and carboxylic acid groups on the surfaces of the modified BACs are critical in CH₃CHO adsorption. Notably, piperazine amination decreased the pore size and volume of the modified BAC, but piperazine/nitric acid impregnation maintained the pore size and volume of the modified BAC. In terms of CH₃CHO adsorption, piperazine/nitric acid impregnation resulted in a superior performance, with greater chemical adsorption. The linkages between the amine and carboxylic acid groups may function differently in piperazine amination and piperazine/nitric acid treatment.

Behaviors of Cellulose-Based Activated Carbon Fiber for Acetaldehyde Adsorption at Low Concentration

The toxic nature of acetaldehyde renders its removal from a wide range of materials highly desirable. Removal of low-concentration acetaldehyde (a group 1 carcinogenic volatile organic compound) using an adsorbent of cellulose-based activated carbon fiber modified by amine functional group (A@CACF-H) is proposed, using 2 ppm of acetaldehyde balanced with N2/O2 (79/21% v/v) observed under continuous flow, with a total flow rate of 100 mL/min over 50 mg of A@CACF-H. The effective removal of the targeted acetaldehyde is achieved by introducing the functionalized amine at optimized content. The removal mechanism of A@CACF-H is elucidated using two-dimensional gas chromatography coupled with time-of-flight mass spectrometry (2D-GC TOF-MS), indicating the efficacy of the proposed acetaldehyde removal method.

Visible light-induced photocatalytic degradation of gas-phase acetaldehyde with platinum/reduced titanium oxide-loaded carbon paper

A simply fabricated, high-surface-area substrate in a highly efficient photocatalyst for the degradation of air pollutant under visible light irradiation.

Quantum dot sensitized electrospun mesoporous titanium dioxide hollow nanofibers for photocatalytic applications

TiO₂ hollow nanofibers prepared by coaxial electrospinning were sensitized with CdS QDs by SILAR method and their photocatalytic dye degradation performance was investigated.